diff options
| author | Ben Culkin <scorpress@gmail.com> | 2020-11-12 20:05:01 -0500 |
|---|---|---|
| committer | Ben Culkin <scorpress@gmail.com> | 2020-11-12 20:05:01 -0500 |
| commit | 6dcd129a10af0034b38bfe843d223c4593deee09 (patch) | |
| tree | e27cf2574a10da36d9a737e1fef48da8e5681da8 /base/src/main/java/bjc/utils/parserutils/TokenTransformer.java | |
| parent | c41cfde634d70c3a50adf3979cc5239e5ae52e73 (diff) | |
Cleanup part 2
Diffstat (limited to 'base/src/main/java/bjc/utils/parserutils/TokenTransformer.java')
| -rw-r--r-- | base/src/main/java/bjc/utils/parserutils/TokenTransformer.java | 148 |
1 files changed, 0 insertions, 148 deletions
diff --git a/base/src/main/java/bjc/utils/parserutils/TokenTransformer.java b/base/src/main/java/bjc/utils/parserutils/TokenTransformer.java deleted file mode 100644 index 6cf2da5..0000000 --- a/base/src/main/java/bjc/utils/parserutils/TokenTransformer.java +++ /dev/null @@ -1,148 +0,0 @@ -package bjc.utils.parserutils; - -import java.util.Deque; -import java.util.function.Consumer; -import java.util.function.Function; -import java.util.function.Predicate; -import java.util.function.UnaryOperator; - -import bjc.data.IHolder; -import bjc.data.ITree; -import bjc.data.Pair; -import bjc.data.Tree; -import bjc.utils.parserutils.TreeConstructor.ConstructorState; -import bjc.utils.parserutils.TreeConstructor.QueueFlattener; - -/* - * Handle creating ASTs from tokens. - */ -final class TokenTransformer<TokenType> implements Consumer<TokenType> { - /* - * Handle operators - */ - private final class OperatorHandler - implements UnaryOperator<ConstructorState<TokenType>> { - /* The handled element. */ - private final TokenType element; - - /* Create a new operator handler. */ - public OperatorHandler(final TokenType element) { - this.element = element; - } - - @Override - public ConstructorState<TokenType> apply(final ConstructorState<TokenType> pair) { - /* - * Replace the current AST with the result of handling an operator - */ - return new ConstructorState<>( - pair.bindLeft(queuedASTs -> handleOperator(queuedASTs))); - } - - private ConstructorState<TokenType> - handleOperator(final Deque<ITree<TokenType>> queuedASTs) { - /* - * The AST we're going to hand back - */ - ITree<TokenType> newAST; - - /* - * Handle special operators - */ - if (isSpecialOperator.test(element)) { - newAST = handleSpecialOperator.apply(element).apply(queuedASTs); - } else { - /* - * Error if we don't have enough for a binary operator - */ - if (queuedASTs.size() < 2) { - final String msg = String.format( - "Attempted to parse binary operator without enough operands\n\tProblem operator is: %s\n\tPossible operand is: %s", - element.toString(), queuedASTs.peek().toString()); - - throw new IllegalStateException(msg); - } - - /* - * Grab the two operands - */ - final ITree<TokenType> right = queuedASTs.pop(); - final ITree<TokenType> left = queuedASTs.pop(); - - /* - * Create a new AST - */ - newAST = new Tree<>(element, left, right); - } - - /* - * Stick it onto the stack - */ - queuedASTs.push(newAST); - - /* - * Hand back the state - */ - return new ConstructorState<>(queuedASTs, newAST); - } - } - - /* The initial state of the transformer. */ - private final IHolder<ConstructorState<TokenType>> initialState; - - /* The predicate tot use to detect operators. */ - private final Predicate<TokenType> operatorPredicate; - - /* The predicate for detecting special operators. */ - private final Predicate<TokenType> isSpecialOperator; - /* The function for handling special operators. */ - private final Function<TokenType, QueueFlattener<TokenType>> handleSpecialOperator; - - /** - * Create a new transformer - * - * @param initialState - * The initial state of the transformer. - * - * @param operatorPredicate - * The predicate to use to identify operators. - * - * @param isSpecialOperator - * The predicate used to identify special - * operators. - * - * @param handleSpecialOperator - * The function used for handling special - * operators. - */ - public TokenTransformer(final IHolder<ConstructorState<TokenType>> initialState, - final Predicate<TokenType> operatorPredicate, - final Predicate<TokenType> isSpecialOperator, - final Function<TokenType, QueueFlattener<TokenType>> handleSpecialOperator) { - this.initialState = initialState; - this.operatorPredicate = operatorPredicate; - this.isSpecialOperator = isSpecialOperator; - this.handleSpecialOperator = handleSpecialOperator; - } - - @Override - public void accept(final TokenType element) { - /* - * Handle operators - */ - if (operatorPredicate.test(element)) { - initialState.transform(new OperatorHandler(element)); - } else { - final ITree<TokenType> newAST = new Tree<>(element); - - /* - * Insert the new tree into the AST - */ - initialState.transform(pair -> new ConstructorState<>(pair.bindLeft(queue -> { - queue.push(newAST); - - return new Pair<>(queue, newAST); - }))); - } - } -} |
