diff options
Diffstat (limited to 'JPratt/src/main/java/com/ashardalon')
46 files changed, 3204 insertions, 0 deletions
diff --git a/JPratt/src/main/java/com/ashardalon/pratt/ParserContext.java b/JPratt/src/main/java/com/ashardalon/pratt/ParserContext.java new file mode 100644 index 0000000..cd6fcc2 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/ParserContext.java @@ -0,0 +1,56 @@ +package com.ashardalon.pratt; + +import com.ashardalon.pratt.tokens.TokenStream; + +/** + * Represents the contextual state passed to a command. + * + * @author EVE + * + * @param <K> + * The key type of the tokens. + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class ParserContext<K, V, C> { + /** + * The source of tokens. + */ + public TokenStream<K, V> tokens; + + /** + * The parser for sub-expressions. + */ + public PrattParser<K, V, C> parse; + + /** + * The state of the parser. + */ + public C state; + + /** + * The initial command for the current expression. + */ + public K initial; + + /** + * Create a new parser context. + * + * @param tokns + * The source of tokens. + * + * @param prse + * The parser to call for sub expressions. + * + * @param stte + * Any state needing to be kept during parsing. + */ + public ParserContext(final TokenStream<K, V> tokns, final PrattParser<K, V, C> prse, final C stte) { + tokens = tokns; + parse = prse; + state = stte; + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/PrattParser.java b/JPratt/src/main/java/com/ashardalon/pratt/PrattParser.java new file mode 100644 index 0000000..ea7afd8 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/PrattParser.java @@ -0,0 +1,334 @@ +package com.ashardalon.pratt; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.HashMap; +import java.util.Iterator; +import java.util.List; +import java.util.Map; + +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.InitialCommand; +import com.ashardalon.pratt.commands.MetaInitialCommand; +import com.ashardalon.pratt.commands.MetaNonInitialCommand; +import com.ashardalon.pratt.commands.NonInitialCommand; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.commands.impls.DefaultInitialCommand; +import com.ashardalon.pratt.commands.impls.DefaultNonInitialCommand; +import com.ashardalon.pratt.tokens.ExpectionNotMet; +import com.ashardalon.pratt.tokens.Token; +import com.ashardalon.pratt.tokens.TokenStream; + +import bjc.data.TransformIterator; +import bjc.data.Tree; +import bjc.utils.funcutils.NumberUtils; +import bjc.utils.parserutils.ParserException; + +/** + * A configurable Pratt parser for expressions. + * + * @author EVE + * + * @param <K> The key type for the tokens. + * + * @param <V> The value type for the tokens. + * + * @param <C> The state type of the parser. + * + * + */ +public class PrattParser<K, V, C> { + /* + * Default commands that error when used. + */ + private final NonInitialCommand<K, V, C> DEFAULT_LEFT_COMMAND = new DefaultNonInitialCommand<>(); + private final List<NonInitialCommand<K, V, C>> DEFAULT_LEFT_LIST = Arrays.asList(DEFAULT_LEFT_COMMAND); + + private final InitialCommand<K, V, C> DEFAULT_NULL_COMMAND = new DefaultInitialCommand<>(); + private final List<InitialCommand<K, V, C>> DEFAULT_NULL_LIST = Arrays.asList(DEFAULT_NULL_COMMAND); + + /* + * Left-commands that depend on what the null command was. + */ + private final Map<K, Map<K, List<NonInitialCommand<K, V, C>>>> dependantLeftCommands; + private final Map<K, Map<K, List<MetaNonInitialCommand<K, V, C>>>> dependantMetaLeftCommands; + /* + * The left commands. + */ + private final Map<K, List<NonInitialCommand<K, V, C>>> leftCommands; + private final Map<K, List<MetaNonInitialCommand<K, V, C>>> metaLeftCommands; + + /* + * The initial commands. + */ + private final Map<K, List<InitialCommand<K, V, C>>> nullCommands; + private final Map<K, List<MetaInitialCommand<K, V, C>>> metaNullCommands; + + /* + * Initial commands only checked for statements. + */ + private final Map<K, List<InitialCommand<K, V, C>>> statementCommands; + private final Map<K, List<MetaInitialCommand<K, V, C>>> metaStatementCommands; + + /** + * Create a new Pratt parser. + * + */ + public PrattParser() { + dependantLeftCommands = new HashMap<>(); + dependantMetaLeftCommands = new HashMap<>(); + + leftCommands = new HashMap<>(); + metaLeftCommands = new HashMap<>(); + + nullCommands = new HashMap<>(); + metaNullCommands = new HashMap<>(); + + statementCommands = new HashMap<>(); + metaStatementCommands = new HashMap<>(); + } + + /** + * Parse an expression. + * + * @param precedence The initial precedence for the expression. + * + * @param tokens The tokens for the expression. + * + * @param state The state of the parser. + * + * @param isStatement Whether or not to parse statements. + * + * @return The expression as an AST. + * + * @throws ParserException If something goes wrong during parsing. + */ + public CommandResult<K, V> parseExpression(final int precedence, final TokenStream<K, V> tokens, final C state, + final boolean isStatement) throws ParserException { + if (precedence < 0) + throw new IllegalArgumentException("Precedence must be greater than zero"); + + ParserContext<K, V, C> parserContext = new ParserContext<>(tokens, this, state); + + Tree<Token<K, V>> ast = null; + CommandResult<K, V> result; + + tokens.mark(); + final Token<K, V> initToken = tokens.current(); + tokens.next(); + tokens.mark(); + + final K initKey = initToken.getKey(); + Iterator<InitialCommand<K, V, C>> nullCommandIter = getInitialCommand(isStatement, initKey, parserContext); + do { + if (!nullCommandIter.hasNext()) { + // Restore to the state we were in before we tried to parse this token. + // Need the commit because rollback doesn't remove marks + tokens.rollback(); + tokens.commit(); + tokens.rollback(); + return CommandResult.backtrack(); + } + + InitialCommand<K, V, C> nullCommand = nullCommandIter.next(); + try { + result = nullCommand.denote(initToken, parserContext); + } catch (ExpectionNotMet enm) { + // TODO: Should enm be used for something here? + result = CommandResult.backtrack(); + } + switch (result.status) { + case SUCCESS: + ast = result.success(); + break; + case FAIL: + return result; + case BACKTRACK: + tokens.rollback(); + break; + default: + throw new IllegalStateException("Unhandled result status " + result.status); + } + parserContext.initial = initKey; + } while (result.status != Status.SUCCESS); + tokens.commit(); + // Think this is right... + // Will get rid of all our active marks. + tokens.commit(); + + int rightPrec = Integer.MAX_VALUE; + + outer: while (true) { + tokens.mark(); + final Token<K, V> tok = tokens.current(); + + final K key = tok.getKey(); + + Iterator<NonInitialCommand<K, V, C>> leftCommandIter = getNonInitialCommand(key, parserContext); + do { + if (!leftCommandIter.hasNext()) { + // Restore to the state we were in before we tried to parse this token. + // Need the commit because rollback doesn't remove marks + tokens.rollback(); + tokens.commit(); + tokens.rollback(); + return CommandResult.backtrack(); + } + + NonInitialCommand<K, V, C> leftCommand = leftCommandIter.next(); + final int leftBind = leftCommand.leftBinding(); + + if (NumberUtils.between(precedence, rightPrec, leftBind)) { + tokens.next(); + tokens.mark(); + + try { + result = leftCommand.denote(ast, tok, parserContext); + rightPrec = leftCommand.nextBinding(); + } catch (ExpectionNotMet enm) { + result = CommandResult.backtrack(); + } + + switch (result.status) { + case SUCCESS: + tokens.commit(); + tokens.commit(); + ast = result.success(); + break; + case FAIL: + return result; + case BACKTRACK: + tokens.rollback(); + break; + default: + throw new IllegalStateException("Unhandled result status " + result.status); + } + } else { + tokens.commit(); + break outer; + } + } while (result.status != Status.SUCCESS); + } + + return CommandResult.success(ast); + } + + /** + * Add a non-initial command to this parser. + * + * @param marker The key that marks the command. + * + * @param comm The command. + */ + public void addNonInitialCommand(final K marker, final NonInitialCommand<K, V, C> comm) { + leftCommands.computeIfAbsent(marker, mrk -> new ArrayList<>()).add(comm); + } + + /** + * Add a initial command to this parser. + * + * @param marker The key that marks the command. + * + * @param comm The command. + */ + public void addInitialCommand(final K marker, final InitialCommand<K, V, C> comm) { + nullCommands.computeIfAbsent(marker, mrk -> new ArrayList<>()).add(comm); + } + + /** + * Add a statement command to this parser. + * + * The difference between statements and initial commands is that statements can + * only appear at the start of the expression. + * + * @param marker The key that marks the command. + * + * @param comm The command. + */ + public void addStatementCommand(final K marker, final InitialCommand<K, V, C> comm) { + statementCommands.computeIfAbsent(marker, mrk -> new ArrayList<>()).add(comm); + } + + /** + * Add a dependent non-initial command to this parser. + * + * @param dependant The dependent that precedes the command. + * + * @param marker The token key that marks the command. + * + * @param comm The command. + */ + public void addDependantCommand(final K dependant, final K marker, final NonInitialCommand<K, V, C> comm) { + Map<K, List<NonInitialCommand<K, V, C>>> dependantMap = dependantLeftCommands.getOrDefault(dependant, + new HashMap<>()); + + dependantMap.computeIfAbsent(marker, mrk -> new ArrayList<>()).add(comm); + } + + /** + * Lookup an initial command. + * + * @param isStatement Whether to look for statement commands or not. + * + * @param key The key of the command. + * + * @param ctx The context for meta-commands. + * + * @return A command attached to that key, or a default implementation. + */ + public Iterator<InitialCommand<K, V, C>> getInitialCommand(boolean isStatement, K key, ParserContext<K, V, C> ctx) { + if (isStatement) { + if (metaStatementCommands.containsKey(key)) { + List<MetaInitialCommand<K, V, C>> lst = metaStatementCommands.get(key); + + return new TransformIterator<>(lst.iterator(), (itm) -> itm.getCommand(ctx)); + } else if (statementCommands.containsKey(key)) { + return statementCommands.get(key).iterator(); + } + } + + if (metaNullCommands.containsKey(key)) { + List<MetaInitialCommand<K, V, C>> lst = metaNullCommands.get(key); + + return new TransformIterator<>(lst.iterator(), (itm) -> itm.getCommand(ctx)); + } + + return nullCommands.getOrDefault(key, DEFAULT_NULL_LIST).iterator(); + } + + /** + * Lookup a non-initial command. + * + * @param key The key of the command. + * + * @param ctx The context for meta-commands. + * + * @return A command attached to that key, or a default implementation. + */ + public Iterator<NonInitialCommand<K, V, C>> getNonInitialCommand(K key, ParserContext<K, V, C> ctx) { + if (dependantMetaLeftCommands.containsKey(ctx.initial)) { + Map<K, List<MetaNonInitialCommand<K, V, C>>> dependantCommands = dependantMetaLeftCommands.get(ctx.initial); + + if (dependantCommands.containsKey(key)) { + List<MetaNonInitialCommand<K, V, C>> lst = dependantCommands.get(key); + + return new TransformIterator<>(lst.iterator(), (itm) -> itm.getCommand(ctx)); + } + } + + if (dependantLeftCommands.containsKey(ctx.initial)) { + Map<K, List<NonInitialCommand<K, V, C>>> dependantCommands = dependantLeftCommands.get(ctx.initial); + + if (dependantCommands.containsKey(key)) { + return dependantCommands.getOrDefault(key, DEFAULT_LEFT_LIST).iterator(); + } + } + + if (metaLeftCommands.containsKey(key)) { + List<MetaNonInitialCommand<K, V, C>> lst = metaLeftCommands.get(key); + return new TransformIterator<>(lst.iterator(), (itm) -> itm.getCommand(ctx)); + } + + return leftCommands.getOrDefault(key, DEFAULT_LEFT_LIST).iterator(); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/blocks/ChainParseBlock.java b/JPratt/src/main/java/com/ashardalon/pratt/blocks/ChainParseBlock.java new file mode 100644 index 0000000..fe04070 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/blocks/ChainParseBlock.java @@ -0,0 +1,86 @@ +package com.ashardalon.pratt.blocks; + +import java.util.Set; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A {@link ParseBlock} for a series of parse blocks, linked by a set of tokens. + * + * Roughly analogous to Perl 6s list associative operators. + * + * @author bjculkin + * + * @param <K> + * The token key type. + * + * @param <V> + * The token value type. + * + * @param <C> + * The parser state type. + * + */ +public class ChainParseBlock<K, V, C> implements ParseBlock<K, V, C> { + private ParseBlock<K, V, C> iner; + + private Set<K> indicators; + + private Token<K, V> trm; + + /** + * Create a new chain parser block. + * + * @param inner + * The block for the chains interior. + * + * @param chainIndicators + * The set of markers that indicate continuing the chain + * + * @param term + * The node in the AST for the expression. + */ + public ChainParseBlock(ParseBlock<K, V, C> inner, Set<K> chainIndicators, Token<K, V> term) { + iner = inner; + indicators = chainIndicators; + trm = term; + } + + @Override + public CommandResult<K, V> parse(ParserContext<K, V, C> ctx) throws ParserException { + CommandResult<K,V> resOuter = iner.parse(ctx); + if (resOuter.status != Status.SUCCESS) return resOuter; + + Tree<Token<K, V>> expression = resOuter.success(); + Token<K, V> currentToken = ctx.tokens.current(); + if(indicators.contains(currentToken.getKey())) { + Tree<Token<K, V>> res = new SimpleTree<>(trm); + res.addChild(expression); + + while(indicators.contains(currentToken.getKey())) { + res.addChild(new SimpleTree<>(currentToken)); + ctx.tokens.next(); + + CommandResult<K,V> resInner = iner.parse(ctx); + if (resInner.status != Status.SUCCESS) return resInner; + + Tree<Token<K, V>> innerExpression = resInner.success(); + res.addChild(innerExpression); + + currentToken = ctx.tokens.current(); + } + + return CommandResult.success(res); + } + + return resOuter; + } + +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/blocks/GrammarParseBlock.java b/JPratt/src/main/java/com/ashardalon/pratt/blocks/GrammarParseBlock.java new file mode 100644 index 0000000..048e9f6 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/blocks/GrammarParseBlock.java @@ -0,0 +1,92 @@ +package com.ashardalon.pratt.blocks; + +import java.util.function.Function; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.PrattParser; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.tokens.Token; +import com.ashardalon.pratt.tokens.TokenStream; + +import bjc.data.Tree; +import bjc.typeclasses.Isomorphism; +import bjc.data.Tree; +import bjc.functypes.*; +import bjc.utils.parserutils.ParserException; + +/** + * A {@link ParseBlock} that parses an expression from a 'inner' grammar. + * + * @author bjculkin + * + * @param <K> The key type of the outer tokens. + * + * @param <V> The value type of the outer tokens. + * + * @param <C> The state type of the outer parser. + * + * @param <K2> The key type of the inner tokens. + * + * @param <V2> The value type of the inner tokens. + * + * @param <C2> The state type of the outer parser. + */ +public class GrammarParseBlock<K, V, C, K2, V2, C2> implements ParseBlock<K, V, C> { + private final PrattParser<K2, V2, C2> innr; + + private final int prcedence; + private final boolean isStatemnt; + + private final Function<TokenStream<K, V>, TokenStream<K2, V2>> tkenTransform; + private final Isomorphism<C, C2> stteTransform; + private final Function<Tree<Token<K2, V2>>, Tree<Token<K, V>>> xpressionTransform; + + /** + * Create a new grammar parser block. + * + * @param inner The inner grammar to parse. + * @param precedence The precedence of the expression to parse. + * @param isStatement Is the expression being parsed in statement + * context? + * @param tokenTransform Function to transform to the new token type. + * @param stateTransform Function to toggle between state types. + * @param expressionTransform Function to transform back to the normal token + * type. + */ + public GrammarParseBlock(final PrattParser<K2, V2, C2> inner, final int precedence, final boolean isStatement, + final Function<TokenStream<K, V>, TokenStream<K2, V2>> tokenTransform, + final Isomorphism<C, C2> stateTransform, + final Function<Tree<Token<K2, V2>>, Tree<Token<K, V>>> expressionTransform) { + innr = inner; + prcedence = precedence; + isStatemnt = isStatement; + tkenTransform = tokenTransform; + stteTransform = stateTransform; + xpressionTransform = expressionTransform; + } + + @Override + public CommandResult<K, V> parse(final ParserContext<K, V, C> ctx) throws ParserException { + final C2 newState = stteTransform.to(ctx.state); + + final TokenStream<K2, V2> newTokens = tkenTransform.apply(ctx.tokens); + + final CommandResult<K2, V2> res = innr.parseExpression(prcedence, newTokens, newState, isStatemnt); + switch (res.status) { + case SUCCESS: + break; + case FAIL: + return CommandResult.fail(); + case BACKTRACK: + return CommandResult.backtrack(); + default: + throw new IllegalStateException("Unhandled status " + res.status); + } + + Tree<Token<K2, V2>> expression = res.success(); + + ctx.state = stteTransform.from(newState); + + return CommandResult.success(xpressionTransform.apply(expression)); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/blocks/ParseBlock.java b/JPratt/src/main/java/com/ashardalon/pratt/blocks/ParseBlock.java new file mode 100644 index 0000000..51aa7fa --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/blocks/ParseBlock.java @@ -0,0 +1,38 @@ +package com.ashardalon.pratt.blocks; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; + +import bjc.utils.parserutils.ParserException; + +/** + * Represents a embedded block in an expression. + * + * @author bjculkin + * + * @param <K> + * The key type of the token. + * + * @param <V> + * The value type of the token. + * + * @param <C> + * The state type of the parser. + */ +@FunctionalInterface +public interface ParseBlock<K, V, C> { + + /** + * Parse the block this represents. + * + * @param ctx + * The context for parsing. + * + * @return A AST for this block. + * + * @throws ParserException + * If something goes wrong during parsing, or the block fails + * validation. + */ + CommandResult<K, V> parse(ParserContext<K, V, C> ctx) throws ParserException; +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/blocks/ParseBlocks.java b/JPratt/src/main/java/com/ashardalon/pratt/blocks/ParseBlocks.java new file mode 100644 index 0000000..89989fd --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/blocks/ParseBlocks.java @@ -0,0 +1,98 @@ +package com.ashardalon.pratt.blocks; + +import java.util.function.Predicate; +import java.util.function.UnaryOperator; + +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; + +/** + * Utility class for creating common implementations of {@link ParseBlock} + * + * @author bjculkin + * + */ +public class ParseBlocks { + /* + * Grammar parse blocks are complex enough to not get a builder method. + */ + + /** + * Create a new repeating parse block. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param inner + * The parse block to repeat. + * + * @param delim + * The token type that separates repetitions. + * + * @param term + * The token type that terminates repetitions. + * + * @param mark + * The token to use as the node in the AST. + * + * @param action + * The action to perform on the state after every repetition. + * + * @return A configured repeating parse block. + */ + public static <K, V, C> ParseBlock<K, V, C> repeating(final ParseBlock<K, V, C> inner, final K delim, + final K term, final Token<K, V> mark, final UnaryOperator<C> action) { + return new RepeatingParseBlock<>(inner, delim, term, mark, action); + } + + /** + * Create a new triggered parse block. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param source + * The block to trigger around. + * + * @param onEnter + * The action to perform upon the state before entering the + * block. + * + * @param onExit + * The action to perform upon the state after exiting the block. + * + * @return A configured trigger parse block. + */ + public static <K, V, C> ParseBlock<K, V, C> trigger(final ParseBlock<K, V, C> source, + final UnaryOperator<C> onEnter, final UnaryOperator<C> onExit) { + return new TriggeredParseBlock<>(onEnter, onExit, source); + } + + /** + * Create a new simple parse block. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of the expression inside the block. + * + * @param terminator + * The key type of the token expected after this block, or null + * if none is expected. + * + * @param validator + * The predicate to use to validate parsed expressions, or null + * if none is used. + * + * @return A configured simple parse block. + */ + public static <K, V, C> ParseBlock<K, V, C> simple(final int precedence, final K terminator, + final Predicate<Tree<Token<K, V>>> validator) { + return new SimpleParseBlock<>(precedence, validator, terminator); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/blocks/RepeatingParseBlock.java b/JPratt/src/main/java/com/ashardalon/pratt/blocks/RepeatingParseBlock.java new file mode 100644 index 0000000..25827b4 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/blocks/RepeatingParseBlock.java @@ -0,0 +1,101 @@ +package com.ashardalon.pratt.blocks; + +import java.util.function.UnaryOperator; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A parse block that can parse a sequnce of zero or more occurances of another + * block. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class RepeatingParseBlock<K, V, C> implements ParseBlock<K, V, C> { + private final ParseBlock<K, V, C> innerBlock; + + private final K delim; + private final K term; + + private final UnaryOperator<C> onDelim; + + private final Token<K, V> mark; + + /** + * Create a new repeating block. + * + * @param inner + * The inner block for elements. + * + * @param delimiter + * The token that delimits elements in the sequence. + * + * @param terminator + * The token that terminates the sequence. + * + * @param marker + * The token to use as the node in the AST. + * + * @param action + * The action to apply to the state after every delimiter. + */ + public RepeatingParseBlock(final ParseBlock<K, V, C> inner, final K delimiter, final K terminator, + final Token<K, V> marker, final UnaryOperator<C> action) { + super(); + + if(inner == null) + throw new NullPointerException("Inner block must not be null"); + else if(delimiter == null) + throw new NullPointerException("Delimiter must not be null"); + else if(terminator == null) throw new NullPointerException("Terminator must not be null"); + + innerBlock = inner; + + delim = delimiter; + term = terminator; + + mark = marker; + + onDelim = action; + } + + @Override + public CommandResult<K, V> parse(final ParserContext<K, V, C> ctx) throws ParserException { + final Tree<Token<K, V>> ret = new SimpleTree<>(mark); + + Token<K, V> tok = ctx.tokens.current(); + + while(!tok.getKey().equals(term)) { + final CommandResult<K,V> resKid = innerBlock.parse(ctx); + if (resKid.status != Status.SUCCESS) return resKid; + Tree<Token<K, V>> kid = resKid.success(); + ret.addChild(kid); + + tok = ctx.tokens.current(); + + ctx.tokens.expect(delim, term); + + if(onDelim != null) { + ctx.state = onDelim.apply(ctx.state); + } + } + + return CommandResult.success(ret); + } + +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/blocks/SimpleParseBlock.java b/JPratt/src/main/java/com/ashardalon/pratt/blocks/SimpleParseBlock.java new file mode 100644 index 0000000..8c4a046 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/blocks/SimpleParseBlock.java @@ -0,0 +1,98 @@ +package com.ashardalon.pratt.blocks; + +import java.util.function.Predicate; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; +import bjc.utils.parserutils.ParserException; + +/** + * Simple implementation of {@link ParseBlock} + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class SimpleParseBlock<K, V, C> implements ParseBlock<K, V, C> { + private final int pow; + + private final K term; + + private final Predicate<Tree<Token<K, V>>> validatr; + + /** + * Create a new block. + * + * @param precedence + * The precedence of this block. + * @param validator + * The predicate to apply to blocks. + * @param terminator + * The token type that terminates the block. If this is null, + * don't check for a terminator. + */ + public SimpleParseBlock(final int precedence, final Predicate<Tree<Token<K, V>>> validator, + final K terminator) { + if(precedence < 0) throw new IllegalArgumentException("Precedence must be non-negative"); + + pow = precedence; + term = terminator; + validatr = validator; + } + + @Override + public CommandResult<K, V> parse(final ParserContext<K, V, C> ctx) throws ParserException { + final CommandResult<K,V> resBlock = ctx.parse.parseExpression(pow, ctx.tokens, ctx.state, false); + if (resBlock.status != Status.SUCCESS) return resBlock; + + Tree<Token<K, V>> res = resBlock.success(); + if(term != null) { + ctx.tokens.expect(term); + } + + if(validatr == null || validatr.test(res)) return CommandResult.success(res); + + // TODO: Figure out the right way to handle error context w/ CommandResult + throw new ParserException("Block failed validation"); + } + + @Override + public int hashCode() { + final int prime = 31; + + int result = 1; + + result = prime * result + pow; + result = prime * result + (term == null ? 0 : term.hashCode()); + + return result; + } + + @Override + public boolean equals(final Object obj) { + if(this == obj) return true; + if(obj == null) return false; + if(!(obj instanceof SimpleParseBlock)) return false; + + final SimpleParseBlock<?, ?, ?> other = (SimpleParseBlock<?, ?, ?>) obj; + + if(pow != other.pow) return false; + + if(term == null) { + if(other.term != null) return false; + } else if(!term.equals(other.term)) return false; + + return true; + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/blocks/TriggeredParseBlock.java b/JPratt/src/main/java/com/ashardalon/pratt/blocks/TriggeredParseBlock.java new file mode 100644 index 0000000..1aeabdb --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/blocks/TriggeredParseBlock.java @@ -0,0 +1,63 @@ +package com.ashardalon.pratt.blocks; + +import java.util.function.UnaryOperator; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.CommandResult.Status; + +import bjc.utils.parserutils.ParserException; + +/** + * A parse block that can adjust the state before handling its context. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * @param <V> + * The value type of the tokens. + * @param <C> + * The state type of the parser. + */ +public class TriggeredParseBlock<K, V, C> implements ParseBlock<K, V, C> { + private final UnaryOperator<C> onEntr; + private final UnaryOperator<C> onExt; + + private final ParseBlock<K, V, C> sourc; + + /** + * Create a new triggered parse block. + * + * @param onEnter + * The action to fire before parsing the block. + * + * @param onExit + * The action to fire after parsing the block. + * + * @param source + * The block to use for parsing. + */ + public TriggeredParseBlock(final UnaryOperator<C> onEnter, final UnaryOperator<C> onExit, + final ParseBlock<K, V, C> source) { + onEntr = onEnter; + onExt = onExit; + sourc = source; + } + + @Override + public CommandResult<K, V> parse(final ParserContext<K, V, C> ctx) throws ParserException { + final C newState = onEntr.apply(ctx.state); + + final ParserContext<K, V, C> newCtx = new ParserContext<>(ctx.tokens, ctx.parse, newState); + + final CommandResult<K,V> res = sourc.parse(newCtx); + + if (res.status != Status.SUCCESS) return res; + + ctx.state = onExt.apply(newState); + + return res; + } + +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/AbstractInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/AbstractInitialCommand.java new file mode 100644 index 0000000..c38aa9b --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/AbstractInitialCommand.java @@ -0,0 +1,45 @@ +package com.ashardalon.pratt.commands; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.tokens.Token; + +import bjc.utils.parserutils.ParserException; + +/** + * Abstract base for initial commands. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public abstract class AbstractInitialCommand<K, V, C> implements InitialCommand<K, V, C> { + @Override + public CommandResult<K, V> denote(final Token<K, V> operator, + final ParserContext<K, V, C> ctx) throws ParserException { + return intNullDenotation(operator, ctx); + } + + /** + * Internal null denotation method. + * + * @param operator + * The operator that was parsed. + * @param ctx + * The parser context at this point. + * + * @return The tree that this method parsed. + * + * @throws ParserException + * If something went wrong while parsing. + */ + protected abstract CommandResult<K, V> intNullDenotation(Token<K, V> operator, + ParserContext<K, V, C> ctx) throws ParserException; + +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/BinaryCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/BinaryCommand.java new file mode 100644 index 0000000..739cb44 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/BinaryCommand.java @@ -0,0 +1,55 @@ +package com.ashardalon.pratt.commands; + +import bjc.data.Tree; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A binary operator. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public abstract class BinaryCommand<K, V, C> extends BinaryPostCommand<K, V, C> { + /** + * Create a new binary operator with the specified precedence. + * + * @param precedence + * The precedence of the operator. + */ + public BinaryCommand(final int precedence) { + super(precedence); + } + + /** + * The right-binding power (right-precedence) of this command. + * + * @return The right binding power of this command. + */ + protected abstract int rightBinding(); + + @Override + public CommandResult<K, V> denote(final Tree<Token<K, V>> operand, + final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + final CommandResult<K,V> opr + = ctx.parse.parseExpression(rightBinding(), ctx.tokens, ctx.state, false); + + if (opr.status != Status.SUCCESS) return opr; + + return CommandResult.success(new SimpleTree<>(operator, operand, opr.success())); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/BinaryPostCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/BinaryPostCommand.java new file mode 100644 index 0000000..bacab23 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/BinaryPostCommand.java @@ -0,0 +1,36 @@ +package com.ashardalon.pratt.commands; + +/** + * A operator with fixed precedence. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public abstract class BinaryPostCommand<K, V, C> extends NonInitialCommand<K, V, C> { + private final int leftPower; + + /** + * Create a new operator with fixed precedence. + * + * @param precedence + * The precedence of the operator. + */ + public BinaryPostCommand(final int precedence) { + if(precedence < 0) throw new IllegalArgumentException("Precedence must be non-negative"); + + leftPower = precedence; + } + + @Override + public int leftBinding() { + return leftPower; + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/BranchInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/BranchInitialCommand.java new file mode 100644 index 0000000..0e17287 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/BranchInitialCommand.java @@ -0,0 +1,39 @@ +package com.ashardalon.pratt.commands; + +import java.util.Map; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.tokens.Token; + +import bjc.utils.parserutils.ParserException; + +/** + * Represents a initial command that has a number of 'sub-commands' in the way that Go/Git CLI does. + * + * @author bjcul + * + * @param <K> Token key type + * @param <V> Token value type + * @param <C> Parser context type + */ +public class BranchInitialCommand<K, V, C> implements InitialCommand<K, V, C> { + private Map<K, InitialCommand<K, V, C>> comMap; + + /** + * Create a new branch initial command + * + * @param mep The map containing the commands + */ + public BranchInitialCommand(Map<K, InitialCommand<K, V, C>> mep) { + this.comMap = mep; + } + + @Override + public CommandResult<K, V> denote(Token<K, V> operator, ParserContext<K, V, C> ctx) throws ParserException { + Token<K, V> curToken = ctx.tokens.current(); + ctx.tokens.expect(comMap.keySet()); + + return comMap.get(curToken.getKey()).denote(curToken, ctx); + } + +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/CommandResult.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/CommandResult.java new file mode 100644 index 0000000..45c1788 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/CommandResult.java @@ -0,0 +1,113 @@ +package com.ashardalon.pratt.commands; + +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; + +/** + * Represents the result of executing a command. + * + * @author bjcul + * + * @param <K> The key type of the tokens + * @param <V> The value type of the tokens + */ +public class CommandResult<K, V> { + /** + * Represents the status of a command execution + * + * @author bjcul + * + */ + public static enum Status { + /** + * The command successfully parsed. + */ + SUCCESS, + /** + * The command failed, in a non-recoverable way + */ + FAIL, + /** + * The command failed. Attempt recovery via backtracking + */ + BACKTRACK + } + + /** + * The status of this command. + */ + public final Status status; + + private Tree<Token<K, V>> success; + + private CommandResult(Status status) { + this.status = status; + } + + /** + * Get the success value of this command, or null if it failed. + * + * @return The success value of the command + */ + public Tree<Token<K, V>> success() { + return success; + } + + /** + * Create a success result + * + * @param <K2> The key type of the token + * @param <V2> The value type of the token + * + * @param succ The tree produced by the command + * + * @return A command result representing a success + */ + public static <K2, V2> CommandResult<K2, V2> success(Tree<Token<K2, V2>> succ) { + CommandResult<K2, V2> result = new CommandResult<>(Status.SUCCESS); + result.success = succ; + return result; + } + + /** + * Create a non-backtracking failure result. + * + * @param <K2> The key type of the token + * @param <V2> The value type of the token + * + * @return A command result representing a non-backtracking fail + */ + public static <K2, V2> CommandResult<K2, V2> fail() { + CommandResult<K2, V2> result = new CommandResult<>(Status.FAIL); + return result; + } + + /** + * Create a backtracking failure result. + * + * @param <K2> The key type of the token + * @param <V2> The value type of the token + * + * @return A command result representing a backtracking fail + */ + public static <K2, V2> CommandResult<K2, V2> backtrack() { + CommandResult<K2, V2> result = new CommandResult<>(Status.BACKTRACK); + return result; + } + + @Override + public String toString() { + StringBuilder builder = new StringBuilder(); + builder.append("CommandResult [status="); + builder.append(status); + if (status == Status.SUCCESS) { + builder.append(", success="); + builder.append(success); + } + builder.append("]"); + return builder.toString(); + } + + +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/InitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/InitialCommand.java new file mode 100644 index 0000000..3b613a3 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/InitialCommand.java @@ -0,0 +1,40 @@ +package com.ashardalon.pratt.commands; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.tokens.Token; + +import bjc.utils.parserutils.ParserException; + +/** + * Represents an initial command in parsing. + * + * @author EVE + * + * @param <K> + * The key type for the tokens. + * + * @param <V> + * The value type for the tokens. + * + * @param <C> + * The state type of the parser. + * + * + */ +@FunctionalInterface +public interface InitialCommand<K, V, C> { + /** + * Construct the null denotation of this command. + * + * @param operator + * The operator for this command. + * @param ctx + * The context for the command. + * + * @return The result of executing the command. + * + * @throws ParserException + * If something goes wrong during parsing. + */ + CommandResult<K, V> denote(Token<K, V> operator, ParserContext<K, V, C> ctx) throws ParserException; +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/MetaInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/MetaInitialCommand.java new file mode 100644 index 0000000..7b9aae0 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/MetaInitialCommand.java @@ -0,0 +1,27 @@ +package com.ashardalon.pratt.commands;
+
+import com.ashardalon.pratt.ParserContext;
+
+/**
+ * A 'meta-command' that yields the actual command to use.
+ *
+ * @author bjculkin
+ *
+ * @param <K>
+ * The key type of the context.
+ * @param <V>
+ * The value type of the context.
+ * @param <C>
+ * The storage type of the context.
+ *
+ */
+public interface MetaInitialCommand<K, V, C> {
+ /**
+ * Get the command to use.
+ *
+ * @param ctx
+ * The current parser context.
+ * @return The command to use.
+ */
+ InitialCommand<K, V, C> getCommand(ParserContext<K, V, C> ctx);
+}
diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/MetaNonInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/MetaNonInitialCommand.java new file mode 100644 index 0000000..4aa5120 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/MetaNonInitialCommand.java @@ -0,0 +1,28 @@ +package com.ashardalon.pratt.commands; + +import com.ashardalon.pratt.ParserContext; + +/** + * A 'meta-command' for non-initial commands. + * + * @author bjculkin + * + * @param <K> + * The token key type. + * + * @param <V> + * The token value type. + * + * @param <C> + * The parser state type. + */ +public interface MetaNonInitialCommand<K, V, C> { + /** + * Get the command to use. + * + * @param ctx + * The context to use. + * @return The command to use. + */ + NonInitialCommand<K, V, C> getCommand(ParserContext<K, V, C> ctx); +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/NonInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/NonInitialCommand.java new file mode 100644 index 0000000..a521e5c --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/NonInitialCommand.java @@ -0,0 +1,66 @@ +package com.ashardalon.pratt.commands; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; +import bjc.utils.parserutils.ParserException; + +/** + * Represents a non-initial command in parsing. + * + * @author EVE + * + * @param <K> + * The key type for the tokens. + * + * @param <V> + * The value type for the tokens. + * + * @param <C> + * The state type of the parser. + * + */ +public abstract class NonInitialCommand<K, V, C> { + /** + * Construct the left denotation of this command. + * + * @param operand + * The left-hand operand of this command. + * @param operator + * The operator for this command. + * + * @param ctx + * The state needed for commands. + * + * @return The result of executing the command. + * + * @throws ParserException + * If something went wrong during parsing. + */ + public abstract CommandResult<K, V> denote(Tree<Token<K, V>> operand, Token<K, V> operator, + ParserContext<K, V, C> ctx) throws ParserException; + + /** + * Get the left-binding power of this command. + * + * This represents the general precedence of this command. + * + * @return The left-binding power of this command. + */ + public abstract int leftBinding(); + + /** + * Get the next-binding power of this command. + * + * This represents the highest precedence of command this command can be + * the left operand of. + * + * This is the same as the left-binding power by default. + * + * @return The next-binding power of this command. + */ + public int nextBinding() { + return leftBinding(); + } +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/BlockInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/BlockInitialCommand.java new file mode 100644 index 0000000..612167a --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/BlockInitialCommand.java @@ -0,0 +1,43 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.blocks.ParseBlock; +import com.ashardalon.pratt.commands.AbstractInitialCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.tokens.Token; + +import bjc.utils.parserutils.ParserException; + +/** + * An initial command that delegates all the work to a {@link ParseBlock} + * + * @author bjculkin + * @param <K> + * The token key type. + * + * @param <V> + * The token value type. + * + * @param <C> + * The parser state type. + * + */ +public class BlockInitialCommand<K, V, C> extends AbstractInitialCommand<K, V, C> { + private final ParseBlock<K, V, C> blck; + + /** + * Create a new block initial command. + * + * @param block + * The block to delegate to. + */ + public BlockInitialCommand(final ParseBlock<K, V, C> block) { + blck = block; + } + + @Override + protected CommandResult<K, V> intNullDenotation(final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + return blck.parse(ctx); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/ChainCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/ChainCommand.java new file mode 100644 index 0000000..5ba84ef --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/ChainCommand.java @@ -0,0 +1,83 @@ +package com.ashardalon.pratt.commands.impls; + +import java.util.Set; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.BinaryPostCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * Create a new chained operator. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class ChainCommand<K, V, C> extends BinaryPostCommand<K, V, C> { + private final Set<K> chainWith; + + private final Token<K, V> chain; + + /** + * Create a new chained operator. + * + * @param precedence + * The precedence of this operator. + * + * @param chainSet + * The operators to chain with. + * + * @param chainMarker + * The token to use as the node in the AST. + */ + public ChainCommand(final int precedence, final Set<K> chainSet, final Token<K, V> chainMarker) { + super(precedence); + + chainWith = chainSet; + chain = chainMarker; + } + + @Override + public CommandResult<K, V> denote(final Tree<Token<K, V>> operand, final Token<K, V> operator, + final ParserContext<K, V, C> ctx) throws ParserException { + CommandResult<K, V> resOuter = ctx.parse.parseExpression(1 + leftBinding(), ctx.tokens, ctx.state, + false); + if (resOuter.status != Status.SUCCESS) return resOuter; + final Tree<Token<K, V>> tree = resOuter.success(); + + final Tree<Token<K, V>> res = new SimpleTree<>(operator, operand, tree); + + if(chainWith.contains(ctx.tokens.current().getKey())) { + final Token<K, V> tok = ctx.tokens.current(); + ctx.tokens.next(); + + CommandResult<K, V> resOther = denote(tree, tok, + new ParserContext<>(ctx.tokens, ctx.parse, ctx.state)); + if (resOther.status != Status.SUCCESS) return resOther; + + final Tree<Token<K, V>> other = resOther.success(); + + return CommandResult.success(new SimpleTree<>(chain, res, other)); + } + + return CommandResult.success(res); + } + + @Override + public int nextBinding() { + return leftBinding() - 1; + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/ConstantCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/ConstantCommand.java new file mode 100644 index 0000000..dd80205 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/ConstantCommand.java @@ -0,0 +1,43 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.InitialCommand; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; +import bjc.utils.parserutils.ParserException; + +/** + * A command that represents a specific tree. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class ConstantCommand<K, V, C> implements InitialCommand<K, V, C> { + private final Tree<Token<K, V>> val; + + /** + * Create a new constant. + * + * @param con + * The tree this constant represents. + */ + public ConstantCommand(final Tree<Token<K, V>> con) { + val = con; + } + + @Override + public CommandResult<K, V> denote(final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + return CommandResult.success(val); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/DefaultInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/DefaultInitialCommand.java new file mode 100644 index 0000000..1c218c9 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/DefaultInitialCommand.java @@ -0,0 +1,30 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.InitialCommand; +import com.ashardalon.pratt.tokens.Token; + +import bjc.utils.parserutils.ParserException; + +/** + * Default implementation of an initial command. + * + * @author EVE + * + * @param <K> + * The key type of the token. + * + * @param <V> + * The value type of the token. + * + * @param <C> + * The state type of the parser. + */ +public class DefaultInitialCommand<K, V, C> implements InitialCommand<K, V, C> { + @Override + public CommandResult<K, V> denote(final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + throw new ParserException("Unexpected token " + operator); + } +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/DefaultNonInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/DefaultNonInitialCommand.java new file mode 100644 index 0000000..8666713 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/DefaultNonInitialCommand.java @@ -0,0 +1,35 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.NonInitialCommand; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; + +/** + * Default implementation of a non-initial command. + * + * @author EVE + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class DefaultNonInitialCommand<K, V, C> extends NonInitialCommand<K, V, C> { + @Override + public CommandResult<K, V> denote(final Tree<Token<K, V>> operand, final Token<K, V> operator, + final ParserContext<K, V, C> ctx) { + throw new UnsupportedOperationException("Default command has no left denotation"); + } + + @Override + public int leftBinding() { + return -1; + } +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/DenestingCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/DenestingCommand.java new file mode 100644 index 0000000..438101e --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/DenestingCommand.java @@ -0,0 +1,50 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.AbstractInitialCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.InitialCommand; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.utils.parserutils.ParserException; + +/** + * A command that denests a input tree. + * + * Useful for processing the result of passing a complex parse group to a + * command. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + * + */ +public class DenestingCommand<K, V, C> extends AbstractInitialCommand<K, V, C> { + private final InitialCommand<K, V, C> wrapped; + + /** + * Create a new transforming initial command. + * + * @param internal + * The initial command to delegate to. + */ + public DenestingCommand(final InitialCommand<K, V, C> internal) { + wrapped = internal; + } + + @Override + protected CommandResult<K, V> intNullDenotation(final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + CommandResult<K, V> res = wrapped.denote(operator, ctx); + if (res.status != Status.SUCCESS) return res; + return CommandResult.success(res.success().getChild(0)); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/GroupingCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/GroupingCommand.java new file mode 100644 index 0000000..284c1e9 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/GroupingCommand.java @@ -0,0 +1,55 @@ +package com.ashardalon.pratt.commands.impls; + +import bjc.data.Tree; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.blocks.ParseBlock; +import com.ashardalon.pratt.commands.AbstractInitialCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A grouping operator. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class GroupingCommand<K, V, C> extends AbstractInitialCommand<K, V, C> { + private final ParseBlock<K, V, C> innerBlock; + + private final Token<K, V> mark; + + /** + * Create a new grouping command. + * + * @param inner + * The inner block. + * + * @param marker + * The token to use as the node in the AST. + */ + public GroupingCommand(final ParseBlock<K, V, C> inner, final Token<K, V> marker) { + innerBlock = inner; + + mark = marker; + } + + @Override + protected CommandResult<K, V> intNullDenotation(final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + final CommandResult<K,V> resOpr = innerBlock.parse(ctx); + Tree<Token<K, V>> opr = resOpr.success(); + return CommandResult.success(new SimpleTree<>(mark, opr)); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/InitialCommands.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/InitialCommands.java new file mode 100644 index 0000000..f4b0bbe --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/InitialCommands.java @@ -0,0 +1,242 @@ +package com.ashardalon.pratt.commands.impls; + +import static com.ashardalon.pratt.blocks.ParseBlocks.repeating; +import static com.ashardalon.pratt.blocks.ParseBlocks.simple; +import static com.ashardalon.pratt.blocks.ParseBlocks.trigger; + +import java.util.function.UnaryOperator; + +import com.ashardalon.pratt.blocks.ParseBlock; +import com.ashardalon.pratt.commands.*; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; +import bjc.functypes.MapBuilder; + +/** + * * Contains factory methods for producing common implementations of + * {@link InitialCommand} + * + * @author EVE + * + */ +public class InitialCommands { + /** + * Create a new unary operator. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of the operator. + * + * @return A command implementing that operator. + */ + public static <K, V, C> InitialCommand<K, V, C> unary(final int precedence) { + return new UnaryCommand<>(precedence); + } + + /** + * Create a new grouping operator. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of the expression in the operator. + * + * @param term + * The type that closes the group. + * + * @param mark + * The token for the AST node of the group. + * + * @return A command implementing the operator. + */ + public static <K, V, C> InitialCommand<K, V, C> grouping(final int precedence, final K term, + final Token<K, V> mark) { + final ParseBlock<K, V, C> innerBlock = simple(precedence, term, null); + + return new GroupingCommand<>(innerBlock, mark); + } + + /** + * Create a new leaf operator. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @return A command implementing the operator. + */ + public static <K, V, C> InitialCommand<K, V, C> leaf() { + return new LeafCommand<>(); + } + + /** + * Create a new pre-ternary operator, like an if-then-else statement. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param cond1 + * The priority of the first block. + * + * @param block1 + * The priority of the second block. + * + * @param block2 + * The priority of the third block. + * + * @param mark1 + * The marker that ends the first block. + * + * @param mark2 + * The marker that ends the second block. + * + * @param term + * The token for the AST node of the group. + * + * @return A command implementing the operator. + */ + public static <K, V, C> InitialCommand<K, V, C> preTernary(final int cond1, final int block1, final int block2, + final K mark1, final K mark2, final Token<K, V> term) { + final ParseBlock<K, V, C> condBlock = simple(cond1, mark1, null); + final ParseBlock<K, V, C> opblock1 = simple(block1, mark2, null); + final ParseBlock<K, V, C> opblock2 = simple(block2, null, null); + + return new PreTernaryCommand<>(condBlock, opblock1, opblock2, term); + } + + /** + * Create a new named constant. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param val + * The value of the constant. + * + * @return A command implementing the constant. + */ + public static <K, V, C> InitialCommand<K, V, C> constant(final Tree<Token<K, V>> val) { + return new ConstantCommand<>(val); + } + + /** + * Create a new delimited command. This is for block-like constructs. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param inner + * The precedence of the inner blocks. + * + * @param delim + * The marker between sub-blocks. + * + * @param mark + * The block terminator. + * + * @param term + * The token for the AST node of the group. + * + * @param onEnter + * The function to apply to the state on entering the block. + * + * @param onDelim + * The function to apply to the state on finishing a sub-block. + * + * @param onExit + * The function to apply to the state on exiting the block. + * + * @param statement + * Whether or not the sub-blocks are statements or expressions. + * + * @return A command implementing the operator. + */ + public static <K, V, C> InitialCommand<K, V, C> delimited(final int inner, final K delim, final K mark, + final Token<K, V> term, final UnaryOperator<C> onEnter, final UnaryOperator<C> onDelim, + final UnaryOperator<C> onExit, final boolean statement) { + final ParseBlock<K, V, C> innerBlock = simple(inner, null, null); + final ParseBlock<K, V, C> delimsBlock = repeating(innerBlock, delim, mark, term, onDelim); + final ParseBlock<K, V, C> scopedBlock = trigger(delimsBlock, onEnter, onExit); + + final GroupingCommand<K, V, C> command = new GroupingCommand<>(scopedBlock, term); + + /* + * Remove the wrapper layer from grouping-command on top of + * RepeatingParseBlock. + */ + return denest(command); + } + + /** + * Create a new denesting command. + * + * This removes one tree-level, and is useful when combining complex + * parse blocks with commands. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param comm + * The command to denest. + * + * @return A command that denests the result of the provided command. + */ + public static <K, V, C> InitialCommand<K, V, C> denest(final InitialCommand<K, V, C> comm) { + return new DenestingCommand<>(comm); + } + + /** + * Create a new 'panfix' command. + * + * Form is <term> <expr> <term> <expr> <term> + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence The precedence for this operator + * @param term The indicator for the operator + * @param marker The token to mark this tree + * + * @return A command that implements a panfix operator + */ + public static <K, V, C> InitialCommand<K, V, C> panfix(final int precedence, final K term, final Token<K, V> marker) { + return new PanfixCommand<>(marker, term, precedence); + } + + /** + * Create a command that unconditionally returns a failure result. + * + * @param <K> Token key type + * @param <V> Token value type + * @param <C> Context type + * + * @return A command that unconditionally fails + */ + public static <K, V, C> InitialCommand<K, V, C> fail() { + return (operator, ctx) -> CommandResult.fail(); + } + + /** + * Create a new builder for branching/sub-command style commands. + * + * @param <K> Token key type + * @param <V> Value key type + * @param <C> Context type + * + * @return A builder for branching/sub-command style commands + */ + public static <K, V, C> MapBuilder<K, InitialCommand<K, V, C>, InitialCommand<K, V, C>> branch() { + return MapBuilder.from(BranchInitialCommand::new); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/LeafCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/LeafCommand.java new file mode 100644 index 0000000..886a377 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/LeafCommand.java @@ -0,0 +1,31 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.InitialCommand; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A operator that stands for itself. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class LeafCommand<K, V, C> implements InitialCommand<K, V, C> { + @Override + public CommandResult<K, V> denote(final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + return CommandResult.success(new SimpleTree<>(operator)); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/LeftBinaryCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/LeftBinaryCommand.java new file mode 100644 index 0000000..c5408d6 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/LeftBinaryCommand.java @@ -0,0 +1,34 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.commands.BinaryCommand; + +/** + * A left-associative operator. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class LeftBinaryCommand<K, V, C> extends BinaryCommand<K, V, C> { + /** + * Create a new left-associative operator. + * + * @param precedence + * The precedence of the operator. + */ + public LeftBinaryCommand(final int precedence) { + super(precedence); + } + + @Override + protected int rightBinding() { + return 1 + leftBinding(); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/NonBinaryCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/NonBinaryCommand.java new file mode 100644 index 0000000..aca3784 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/NonBinaryCommand.java @@ -0,0 +1,39 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.commands.BinaryCommand; + +/** + * A non-associative operator. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class NonBinaryCommand<K, V, C> extends BinaryCommand<K, V, C> { + /** + * Create a new non-associative operator. + * + * @param precedence + * The precedence of the operator. + */ + public NonBinaryCommand(final int precedence) { + super(precedence); + } + + @Override + protected int rightBinding() { + return 1 + leftBinding(); + } + + @Override + public int nextBinding() { + return leftBinding() - 1; + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/NonInitialCommands.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/NonInitialCommands.java new file mode 100644 index 0000000..41f0bab --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/NonInitialCommands.java @@ -0,0 +1,167 @@ +package com.ashardalon.pratt.commands.impls; + +import java.util.Set; + +import com.ashardalon.pratt.blocks.ParseBlock; +import com.ashardalon.pratt.blocks.SimpleParseBlock; +import com.ashardalon.pratt.commands.NonInitialCommand; +import com.ashardalon.pratt.tokens.Token; + +/** + * Contains factory methods for producing common implementations of + * {@link NonInitialCommand} + * + * @author EVE + * + */ +public class NonInitialCommands { + /** + * Create a left-associative infix operator. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of the operator. + * + * @return A command implementing that operator. + */ + public static <K, V, C> NonInitialCommand<K, V, C> infixLeft(final int precedence) { + return new LeftBinaryCommand<>(precedence); + } + + /** + * Create a right-associative infix operator. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of the operator. + * + * @return A command implementing that operator. + */ + public static <K, V, C> NonInitialCommand<K, V, C> infixRight(final int precedence) { + return new RightBinaryCommand<>(precedence); + } + + /** + * Create a non-associative infix operator. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of the operator. + * + * @return A command implementing that operator. + */ + public static <K, V, C> NonInitialCommand<K, V, C> infixNon(final int precedence) { + return new NonBinaryCommand<>(precedence); + } + + /** + * Create a chained operator. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of the operator. + * + * @param chainSet + * The operators it forms a chain with. + * + * @param marker + * The token to use as the AST node for the chained operators. + * + * @return A command implementing that operator. + */ + public static <K, V, C> NonInitialCommand<K, V, C> chain(final int precedence, final Set<K> chainSet, + final Token<K, V> marker) { + return new ChainCommand<>(precedence, chainSet, marker); + } + + /** + * Create a postfix operator. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of the operator. + * + * @return A command implementing that operator. + */ + public static <K, V, C> NonInitialCommand<K, V, C> postfix(final int precedence) { + return new PostfixCommand<>(precedence); + } + + /** + * Create a post-circumfix operator. + * + * This is an operator in form similar to array indexing. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of this operator + * + * @param insidePrecedence + * The precedence of the expression inside the operator + * + * @param closer + * The token that closes the circumfix. + * + * @param marker + * The token to use as the AST node for the operator. + * + * @return A command implementing that operator. + */ + public static <K, V, C> NonInitialCommand<K, V, C> postCircumfix(final int precedence, + final int insidePrecedence, final K closer, final Token<K, V> marker) { + final ParseBlock<K, V, C> innerBlock = new SimpleParseBlock<>(insidePrecedence, null, closer); + + return new PostCircumfixCommand<>(precedence, innerBlock, marker); + } + + /** + * Create a ternary operator. + * + * This is like C's ?: operator. + * + * @param <K> The key type for the tokens. + * @param <V> The value type for the tokens. + * @param <C> The context type for the tokens. + * + * @param precedence + * The precedence of the operator. + * + * @param insidePrecedence + * The precedence of the inner section of the operator. + * + * @param closer + * The token that marks the end of the inner section. + * + * @param marker + * The token to use as the AST node for the operator. + * + * @param nonassoc + * True if the command is non-associative, false otherwise. + * + * @return A command implementing this operator. + */ + public static <K, V, C> NonInitialCommand<K, V, C> ternary(final int precedence, final int insidePrecedence, + final K closer, final Token<K, V> marker, final boolean nonassoc) { + final ParseBlock<K, V, C> innerBlock = new SimpleParseBlock<>(insidePrecedence, null, closer); + + return new TernaryCommand<>(precedence, innerBlock, marker, nonassoc); + } +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PanfixCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PanfixCommand.java new file mode 100644 index 0000000..99d43c8 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PanfixCommand.java @@ -0,0 +1,55 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.InitialCommand; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.SimpleTree; +import bjc.data.Tree; +import bjc.utils.parserutils.ParserException; + +/** + * Represents a 'panfix' command, one where the operator is repeated prefix, infix and postfix. + * @author bjcul + * + * @param <K> The key type of the token + * @param <V> The value type of the token + * @param <C> The context type of the parser + */ +public final class PanfixCommand<K, V, C> implements InitialCommand<K, V, C> { + private final Token<K, V> marker; + private final K term; + private final int precedence; + + /** + * Create a new panfix command. + * + * @param marker The marker token. + * @param term The value to use as the root of the result-tree + * @param precedence The precedence for this command + */ + public PanfixCommand(Token<K, V> marker, K term, int precedence) { + this.marker = marker; + this.term = term; + this.precedence = precedence; + } + + @Override + public CommandResult<K, V> denote(Token<K, V> operator, ParserContext<K, V, C> ctx) throws ParserException { + CommandResult<K,V> resLeftSide = ctx.parse.parseExpression(precedence + 1, ctx.tokens, ctx.state, false); + if (resLeftSide.status != Status.SUCCESS) return resLeftSide; + Tree<Token<K, V>> leftSide = resLeftSide.success(); + ctx.tokens.expect(term); + ctx.tokens.next(); + + CommandResult<K, V> resRightSide = ctx.parse.parseExpression(precedence + 1, ctx.tokens, ctx.state, false); + if (resLeftSide.status != Status.SUCCESS) return resRightSide; + Tree<Token<K,V>> rightSide = resRightSide.success(); + ctx.tokens.expect(term); + ctx.tokens.next(); + + return CommandResult.success(new SimpleTree<>(marker, leftSide, rightSide)); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PostCircumfixCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PostCircumfixCommand.java new file mode 100644 index 0000000..c5b60a1 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PostCircumfixCommand.java @@ -0,0 +1,64 @@ +package com.ashardalon.pratt.commands.impls; + +import bjc.data.Tree; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.blocks.ParseBlock; +import com.ashardalon.pratt.commands.BinaryPostCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A post-circumfix operator, like array indexing. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class PostCircumfixCommand<K, V, C> extends BinaryPostCommand<K, V, C> { + private final ParseBlock<K, V, C> innerBlock; + + private final Token<K, V> mark; + + /** + * Create a new post-circumfix operator. + * + * @param precedence + * The precedence of the operator. + * + * @param inner + * The block inside the expression. + * + * @param marker + * The token to use as the node for the AST. + */ + public PostCircumfixCommand(final int precedence, final ParseBlock<K, V, C> inner, final Token<K, V> marker) { + super(precedence); + + if(inner == null) throw new NullPointerException("Inner block must not be null"); + + innerBlock = inner; + + mark = marker; + } + + @Override + public CommandResult<K, V> denote(final Tree<Token<K, V>> operand, final Token<K, V> operator, + final ParserContext<K, V, C> ctx) throws ParserException { + final CommandResult<K,V> insideRes = innerBlock.parse(ctx); + if (insideRes.status != Status.SUCCESS) return insideRes; + Tree<Token<K, V>> inside = insideRes.success(); + return CommandResult.success(new SimpleTree<>(mark, operand, inside)); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PostfixCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PostfixCommand.java new file mode 100644 index 0000000..84ac61d --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PostfixCommand.java @@ -0,0 +1,43 @@ +package com.ashardalon.pratt.commands.impls; + +import bjc.data.Tree; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.BinaryPostCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A postfix operator. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class PostfixCommand<K, V, C> extends BinaryPostCommand<K, V, C> { + /** + * Create a new postfix operator. + * + * @param precedence + * The precedence of the operator. + */ + public PostfixCommand(final int precedence) { + super(precedence); + } + + @Override + public CommandResult<K, V> denote(final Tree<Token<K, V>> operand, final Token<K, V> operator, + final ParserContext<K, V, C> ctx) throws ParserException { + return CommandResult.success(new SimpleTree<>(operator, operand)); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PreTernaryCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PreTernaryCommand.java new file mode 100644 index 0000000..cd01333 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/PreTernaryCommand.java @@ -0,0 +1,85 @@ +package com.ashardalon.pratt.commands.impls; + +import bjc.data.Tree; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.blocks.ParseBlock; +import com.ashardalon.pratt.commands.AbstractInitialCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A prefix ternary operator, like an if/then/else group. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class PreTernaryCommand<K, V, C> extends AbstractInitialCommand<K, V, C> { + private final Token<K, V> trm; + + private final ParseBlock<K, V, C> condBlock; + + private final ParseBlock<K, V, C> opblock1; + private final ParseBlock<K, V, C> opblock2; + + /** + * Create a new ternary statement. + * + * @param cond + * The block for handling the condition. + * + * @param op1 + * The block for handling the first operator. + * + * @param op2 + * The block for handling the second operator. + * + * @param term + * The token to use as the node for the AST. + */ + public PreTernaryCommand(final ParseBlock<K, V, C> cond, final ParseBlock<K, V, C> op1, + final ParseBlock<K, V, C> op2, final Token<K, V> term) { + super(); + + if(cond == null) + throw new NullPointerException("Cond block must not be null"); + else if(op1 == null) + throw new NullPointerException("Op block #1 must not be null"); + else if(op2 == null) throw new NullPointerException("Op block #2 must not be null"); + + condBlock = cond; + opblock1 = op1; + opblock2 = op2; + + trm = term; + } + + @Override + protected CommandResult<K, V> intNullDenotation(final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + final CommandResult<K,V> condRes = condBlock.parse(ctx); + if (condRes.status != Status.SUCCESS) return condRes; + Tree<Token<K, V>> cond = condRes.success(); + + final CommandResult<K,V> op1Res = opblock1.parse(ctx); + if (op1Res.status != Status.SUCCESS) return op1Res; + Tree<Token<K, V>> op1 = op1Res.success(); + + final CommandResult<K,V> op2Res = opblock2.parse(ctx); + if (op2Res.status != Status.SUCCESS) return op2Res; + Tree<Token<K, V>> op2 = op2Res.success(); + return CommandResult.success(new SimpleTree<>(trm, cond, op1, op2)); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/RightBinaryCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/RightBinaryCommand.java new file mode 100644 index 0000000..9145fd6 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/RightBinaryCommand.java @@ -0,0 +1,32 @@ +package com.ashardalon.pratt.commands.impls; + +import com.ashardalon.pratt.commands.BinaryCommand; + +/** + * A right-associative binary operator. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * @param <V> + * The value type of the tokens. + * @param <C> + * The state type of the parser. + */ +public class RightBinaryCommand<K, V, C> extends BinaryCommand<K, V, C> { + /** + * Create a new right-associative operator. + * + * @param precedence + * The precedence of the operator. + */ + public RightBinaryCommand(final int precedence) { + super(precedence); + } + + @Override + protected int rightBinding() { + return leftBinding(); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/TernaryCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/TernaryCommand.java new file mode 100644 index 0000000..b52107f --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/TernaryCommand.java @@ -0,0 +1,78 @@ +package com.ashardalon.pratt.commands.impls; + +import bjc.data.Tree; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.blocks.ParseBlock; +import com.ashardalon.pratt.commands.BinaryPostCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A ternary command, like C's ?: + * + * @author bjculkin + * + * @param <K> The key type of the tokens. + * + * @param <V> The value type of the tokens. + * + * @param <C> The state type of the parser. + */ +public class TernaryCommand<K, V, C> extends BinaryPostCommand<K, V, C> { + private final ParseBlock<K, V, C> innerBlck; + + private final Token<K, V> mark; + + private final boolean nonassoc; + + /** + * Create a new ternary command. + * + * @param precedence The precedence of this operator. + * + * @param innerBlock The representation of the inner block of the expression. + * + * @param marker The token to use as the root of the AST node. + * + * @param isNonassoc Whether or not the conditional is associative. + */ + public TernaryCommand(final int precedence, final ParseBlock<K, V, C> innerBlock, final Token<K, V> marker, + final boolean isNonassoc) { + super(precedence); + + if (innerBlock == null) + throw new NullPointerException("Inner block must not be null"); + else if (marker == null) + throw new NullPointerException("Marker must not be null"); + + innerBlck = innerBlock; + mark = marker; + nonassoc = isNonassoc; + } + + @Override + public CommandResult<K, V> denote(final Tree<Token<K, V>> operand, final Token<K, V> operator, + final ParserContext<K, V, C> ctx) throws ParserException { + final CommandResult<K, V> innerRes = innerBlck.parse(ctx); + if (innerRes.status != Status.SUCCESS) return innerRes; + Tree<Token<K, V>> inner = innerRes.success(); + + final CommandResult<K,V> outerRes = ctx.parse.parseExpression(1 + leftBinding(), ctx.tokens, ctx.state, false); + if (outerRes.status != Status.SUCCESS) return outerRes; + Tree<Token<K, V>> outer = outerRes.success(); + return CommandResult.success(new SimpleTree<>(mark, inner, operand, outer)); + } + + @Override + public int nextBinding() { + if (nonassoc) + return leftBinding() - 1; + + return leftBinding(); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/TransformingInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/TransformingInitialCommand.java new file mode 100644 index 0000000..9a08c44 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/TransformingInitialCommand.java @@ -0,0 +1,59 @@ +package com.ashardalon.pratt.commands.impls; + +import java.util.function.UnaryOperator; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.AbstractInitialCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.InitialCommand; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.Tree; +import bjc.utils.parserutils.ParserException; + +/** + * An initial command that transforms the result of another command. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class TransformingInitialCommand<K, V, C> extends AbstractInitialCommand<K, V, C> { + private final InitialCommand<K, V, C> internl; + + private final UnaryOperator<Tree<Token<K, V>>> transfrm; + + /** + * Create a new transforming initial command. + * + * @param internal + * The initial command to delegate to. + * + * @param transform + * The transform to apply to the returned tree. + */ + public TransformingInitialCommand(final InitialCommand<K, V, C> internal, + final UnaryOperator<Tree<Token<K, V>>> transform) { + super(); + internl = internal; + transfrm = transform; + } + + @Override + protected CommandResult<K, V> intNullDenotation(final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + CommandResult<K,V> result = internl.denote(operator, ctx); + if (result.status != Status.SUCCESS) return result; + + return CommandResult.success(transfrm.apply(result.success())); + } + +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/UnaryCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/UnaryCommand.java new file mode 100644 index 0000000..a7efdc3 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/UnaryCommand.java @@ -0,0 +1,52 @@ +package com.ashardalon.pratt.commands.impls; + +import bjc.data.Tree; + +import com.ashardalon.pratt.ParserContext; +import com.ashardalon.pratt.commands.AbstractInitialCommand; +import com.ashardalon.pratt.commands.CommandResult; +import com.ashardalon.pratt.commands.CommandResult.Status; +import com.ashardalon.pratt.tokens.Token; + +import bjc.data.SimpleTree; +import bjc.utils.parserutils.ParserException; + +/** + * A unary operator. + * + * @author bjculkin + * + * @param <K> + * The key type of the tokens. + * + * @param <V> + * The value type of the tokens. + * + * @param <C> + * The state type of the parser. + */ +public class UnaryCommand<K, V, C> extends AbstractInitialCommand<K, V, C> { + private final int nullPwer; + + /** + * Create a new unary command. + * + * @param precedence + * The precedence of this operator. + */ + public UnaryCommand(final int precedence) { + if(precedence < 0) throw new IllegalArgumentException("Precedence must be non-negative"); + + nullPwer = precedence; + } + + @Override + protected CommandResult<K, V> intNullDenotation(final Token<K, V> operator, final ParserContext<K, V, C> ctx) + throws ParserException { + CommandResult<K,V> result = ctx.parse.parseExpression(nullPwer, ctx.tokens, ctx.state, false); + if (result.status != Status.SUCCESS) return result; + final Tree<Token<K, V>> opr = result.success(); + + return CommandResult.success(new SimpleTree<>(operator, opr)); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/parsing/package-info.java b/JPratt/src/main/java/com/ashardalon/pratt/parsing/package-info.java new file mode 100644 index 0000000..7108bc2 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/parsing/package-info.java @@ -0,0 +1 @@ +package com.ashardalon.pratt.parsing;
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/tokens/ExpectionNotMet.java b/JPratt/src/main/java/com/ashardalon/pratt/tokens/ExpectionNotMet.java new file mode 100644 index 0000000..b700203 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/tokens/ExpectionNotMet.java @@ -0,0 +1,23 @@ +package com.ashardalon.pratt.tokens; + +import bjc.utils.parserutils.ParserException; + +/** + * The exception thrown when an expectation fails. + * + * @author EVE + * + */ +public class ExpectionNotMet extends ParserException { + private static final long serialVersionUID = 4299299480127680805L; + + /** + * Create a new exception with the specified message. + * + * @param msg + * The message of the exception. + */ + public ExpectionNotMet(final String msg) { + super(msg); + } +}
\ No newline at end of file diff --git a/JPratt/src/main/java/com/ashardalon/pratt/tokens/SimpleToken.java b/JPratt/src/main/java/com/ashardalon/pratt/tokens/SimpleToken.java new file mode 100644 index 0000000..ee68835 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/tokens/SimpleToken.java @@ -0,0 +1,60 @@ +package com.ashardalon.pratt.tokens; + +import java.util.Objects; + +/** + * Simple token implementation + * + * @author bjcul + * + * @param <K> The key type + * @param <V> The value type + * + */ +public class SimpleToken<K, V> implements Token<K, V> { + private K key; + private V value; + + /** + * Create a new token + * @param key The key + * @param value The value + */ + public SimpleToken(K key, V value) { + super(); + this.key = key; + this.value = value; + } + + @Override + public K getKey() { + return key; + } + + @Override + public V getValue() { + return value; + } + + @Override + public int hashCode() { + return Objects.hash(key, value); + } + + @Override + public boolean equals(Object obj) { + if (this == obj) + return true; + if (obj == null) + return false; + if (getClass() != obj.getClass()) + return false; + SimpleToken<?, ?> other = (SimpleToken<?, ?>) obj; + return Objects.equals(key, other.key) && Objects.equals(value, other.value); + } + + @Override + public String toString() { + return "SimpleToken [key=" + key + ", value=" + value + "]"; + } +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/tokens/SimpleTokenStream.java b/JPratt/src/main/java/com/ashardalon/pratt/tokens/SimpleTokenStream.java new file mode 100644 index 0000000..cc751d1 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/tokens/SimpleTokenStream.java @@ -0,0 +1,82 @@ +package com.ashardalon.pratt.tokens; + +import java.util.Iterator; + +import bjc.data.MarkListIterator; + +/** + * Simple token stream implementation + * @author bjcul + * + * @param <K> The key type + * @param <V> The value type + */ +public class SimpleTokenStream<K, V> extends TokenStream<K, V> { + private final MarkListIterator<Token<K, V>> iter; + + private Token<K, V> curr; + + private Token<K, V> terminal; + /** + * Create a new token stream from a iterator. + * + * @param itr The iterator to use. + * @param terminal The terminal token to use for end-of-stream + * + */ + public SimpleTokenStream(final Iterator<Token<K, V>> itr, Token<K, V> terminal) { + this.iter = new MarkListIterator<>(itr); + this.terminal = terminal; + } + + @Override + public Token<K, V> current() { + // Prime stream if necessary + if (curr == null) + return next(); + return curr; + } + + @Override + public Token<K, V> next() { + if (iter.hasNext()) { + curr = iter.next(); + } else { + curr = terminal; + } + + return curr; + } + + @Override + public boolean hasNext() { + return iter.hasNext(); + } + + @Override + public void mark() { + iter.mark(); + } + + @Override + public void commit() { + iter.commit(); + + if (!iter.hasMark()) { + // No marks outstanding; we can release the previous state + iter.reset(); + } + } + + @Override + public void rollback() { + iter.rollback(); + + curr = iter.current(); + } + + @Override + public boolean hasMark() { + return iter.hasMark(); + } +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/tokens/StringToken.java b/JPratt/src/main/java/com/ashardalon/pratt/tokens/StringToken.java new file mode 100644 index 0000000..e9b17dc --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/tokens/StringToken.java @@ -0,0 +1,83 @@ +package com.ashardalon.pratt.tokens; + +/** + * Simple token implementation for strings. + * + * @author EVE + * + */ +public class StringToken implements Token<String, String> { + private final String key; + private final String val; + + /** + * Create a new string token. + * + * @param ky + * The key for the token. + * + * @param vl + * The value for the token. + */ + public StringToken(final String ky, final String vl) { + key = ky; + val = vl; + } + + @Override + public String getKey() { + return key; + } + + @Override + public String getValue() { + return val; + } + + @Override + public int hashCode() { + final int prime = 31; + + int result = 1; + result = prime * result + (key == null ? 0 : key.hashCode()); + result = prime * result + (val == null ? 0 : val.hashCode()); + + return result; + } + + @Override + public boolean equals(final Object obj) { + if(this == obj) return true; + if(obj == null) return false; + if(!(obj instanceof StringToken)) return false; + + final StringToken other = (StringToken) obj; + + if(key == null) { + if(other.key != null) return false; + } else if(!key.equals(other.key)) return false; + + if(val == null) { + if(other.val != null) return false; + } else if(!val.equals(other.val)) return false; + + return true; + } + + @Override + public String toString() { + return String.format("StringToken [key='%s', val='%s']", key, val); + } + + /** + * Create a new literal token (has same key/value). + * + * @param val + * The value for the literal token. + * + * @return A literal token with that key. + */ + public static StringToken litToken(final String val) { + return new StringToken(val, val); + } +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/tokens/StringTokenStream.java b/JPratt/src/main/java/com/ashardalon/pratt/tokens/StringTokenStream.java new file mode 100644 index 0000000..fb25016 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/tokens/StringTokenStream.java @@ -0,0 +1,84 @@ +package com.ashardalon.pratt.tokens; + +import static com.ashardalon.pratt.tokens.StringToken.litToken; + +import java.util.Iterator; + +import bjc.data.MarkListIterator; + +/** + * Simple implementation of token stream for strings. + * + * The terminal token here is represented by a token with type and value + * '(end)'. + * + * @author EVE + * + */ +public class StringTokenStream extends TokenStream<String, String> { + private final MarkListIterator<Token<String, String>> iter; + + private Token<String, String> curr; + + /** + * Create a new token stream from a iterator. + * + * @param itr + * The iterator to use. + * + */ + public StringTokenStream(final Iterator<Token<String, String>> itr) { + iter = new MarkListIterator<>(itr); + } + + @Override + public Token<String, String> current() { + // Prime stream if necessary + if (curr == null) + return next(); + return curr; + } + + @Override + public Token<String, String> next() { + if(iter.hasNext()) { + curr = iter.next(); + } else { + curr = litToken("(end)"); + } + + return curr; + } + + @Override + public boolean hasNext() { + return iter.hasNext(); + } + + @Override + public void mark() { + iter.mark(); + } + + @Override + public void commit() { + iter.commit(); + + if (!iter.hasMark()) { + // No marks outstanding; we can release the previous state + iter.reset(); + } + } + + @Override + public void rollback() { + iter.rollback(); + + curr = iter.current(); + } + + @Override + public boolean hasMark() { + return iter.hasMark(); + } +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/tokens/Token.java b/JPratt/src/main/java/com/ashardalon/pratt/tokens/Token.java new file mode 100644 index 0000000..86f0d05 --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/tokens/Token.java @@ -0,0 +1,30 @@ +package com.ashardalon.pratt.tokens; + +/** + * Represents a simple parsing token. + * + * @author EVE + * + * @param <K> + * The key type of this token. Represents the type of the token. + * + * @param <V> + * The value type of this token. Represents any additional data for the + * token. + * + */ +public interface Token<K, V> { + /** + * Get the key for this token. + * + * @return The key for this token + */ + K getKey(); + + /** + * Get the value for this token. + * + * @return The value for this token. + */ + V getValue(); +} diff --git a/JPratt/src/main/java/com/ashardalon/pratt/tokens/TokenStream.java b/JPratt/src/main/java/com/ashardalon/pratt/tokens/TokenStream.java new file mode 100644 index 0000000..3f2681b --- /dev/null +++ b/JPratt/src/main/java/com/ashardalon/pratt/tokens/TokenStream.java @@ -0,0 +1,106 @@ +package com.ashardalon.pratt.tokens; + +import java.util.Arrays; +import java.util.HashSet; +import java.util.Iterator; +import java.util.Set; + +import bjc.utils.funcutils.StringUtils; + +/** + * A stream of tokens. + * + * @author EVE + * + * @param <K> + * The key type of the token. + * + * @param <V> + * The value type of the token. + */ +public abstract class TokenStream<K, V> implements Iterator<Token<K, V>> { + /** + * Get the current token. + * + * @return The current token. + */ + public abstract Token<K, V> current(); + + @Override + public abstract Token<K, V> next(); + + @Override + public abstract boolean hasNext(); + + /** + * Place a mark in the current stream, which can be either returned to or abandoned later on. + */ + public abstract void mark(); + + /** + * Reset the stream to the state it was in when the last mark was taken. + */ + public abstract void rollback(); + + /** + * Check if the stream has at least one mark. + * + * @return Whether or not at least one mark exists. + */ + public abstract boolean hasMark(); + + /** + * Remove the last mark placed into the stream. This prevents returning to it later on. + */ + public abstract void commit(); + + /** + * Utility method for checking that the next token is one of a specific + * set of types, and then consuming it. + * + * @param expectedKeys + * The expected values + * + * @throws ExpectionNotMet + * If the token is not one of the expected types. + */ + public void expect(final Set<K> expectedKeys) throws ExpectionNotMet { + final K curKey = current().getKey(); + + if(!expectedKeys.contains(curKey)) { + final String expectedList = StringUtils.toEnglishList(expectedKeys.toArray(), false); + + throw new ExpectionNotMet("One of '" + expectedList + "' was expected, not " + curKey); + } + + next(); + } + + /** + * Utility method for checking that the next token is one of a specific + * set of types, and then consuming it. + * + * @param expectedKeys + * The expected values + * + * @throws ExpectionNotMet + * If the token is not one of the expected types. + */ + @SafeVarargs + public final void expect(final K... expectedKeys) throws ExpectionNotMet { + HashSet<K> keys = new HashSet<>(Arrays.asList(expectedKeys)); + expect(keys); + } + + /** + * Check whether the head token is a certain type. + * + * @param val + * The type to check for. + * + * @return Whether or not the head token is of that type. + */ + public boolean headIs(final K val) { + return current().getKey().equals(val); + } +} |