diff options
Diffstat (limited to 'RGens/src/main/java/bjc/rgens/newparser/RGrammarParser.java')
| -rw-r--r-- | RGens/src/main/java/bjc/rgens/newparser/RGrammarParser.java | 94 |
1 files changed, 41 insertions, 53 deletions
diff --git a/RGens/src/main/java/bjc/rgens/newparser/RGrammarParser.java b/RGens/src/main/java/bjc/rgens/newparser/RGrammarParser.java index 9717eee..22e0ca7 100644 --- a/RGens/src/main/java/bjc/rgens/newparser/RGrammarParser.java +++ b/RGens/src/main/java/bjc/rgens/newparser/RGrammarParser.java @@ -20,9 +20,9 @@ public class RGrammarParser { /* * Templates for level-dependent delimiters. */ - private static final String TMPL_PRAGMA_BLOCK_DELIM = "\\R\\t{%d}(?!\\t)"; + private static final String TMPL_PRAGMA_BLOCK_DELIM = "\\R\\t{%d}(?!\\t)"; private static final String TMPL_RULEDECL_BLOCK_DELIM = "\\R\\t\\t{%d}"; - private static final String TMPL_WHERE_BLOCK_DELIM = "\\R\\t{%d}(?:in|end)\\R"; + private static final String TMPL_WHERE_BLOCK_DELIM = "\\R\\t{%d}(?:in|end)\\R"; private static final String TMPL_TOPLEVEL_BLOCK_DELIM = "\\R\\t{%d}\\.?\\R"; /* @@ -40,7 +40,8 @@ public class RGrammarParser { int sep = body.indexOf(' '); if (sep != -1) { - throw new GrammarException("Initial-rule pragma takes only one argument, the name of the initial rule"); + String msg = "Initial-rule pragma takes only one argument, the name of the initial rule"; + throw new GrammarException(msg); } build.setInitialRule(body); @@ -58,36 +59,22 @@ public class RGrammarParser { String[] parts = body.trim().split(" "); if (parts.length != 2) { - throw new GrammarException("Suffix-with pragma takes two arguments," - + " the name of the rule to suffix, then what to suffix it with"); + String msg = "Suffix-with pragma takes two arguments, the name of the rule to suffix, then what to suffix it with"; + throw new GrammarException(msg); } - String name = parts[0]; - String suffix = parts[1]; - - if (name.equals("")) { - throw new GrammarException("The empty string is not a valid rule name"); - } - - build.suffixWith(name, suffix); + build.suffixWith(parts[0], parts[1]); }); pragmas.put("prefix-with", (body, build, level) -> { String[] parts = body.trim().split(" "); if (parts.length != 2) { - throw new GrammarException("Prefix-with pragma takes two arguments," - + " the name of the rule to prefix, then what to prefix it with"); - } - - String name = parts[0]; - String prefix = parts[1]; - - if (name.equals("")) { - throw new GrammarException("The empty string is not a valid rule name"); + String msg = "Prefix-with pragma takes two arguments, the name of the rule to prefix, then what to prefix it with"; + throw new GrammarException(msg); } - build.prefixWith(name, prefix); + build.prefixWith(parts[0], parts[1]); }); } @@ -103,8 +90,9 @@ public class RGrammarParser { * Thrown if the grammar has a syntax error. */ public static RGrammar readGrammar(Reader is) throws GrammarException { - try (BlockReader reader = new SimpleBlockReader(String.format(TMPL_TOPLEVEL_BLOCK_DELIM, - 0), is)) { + String dlm = String.format(TMPL_TOPLEVEL_BLOCK_DELIM, 0); + + try (BlockReader reader = new SimpleBlockReader(dlm, is)) { if (!reader.hasNextBlock()) { throw new GrammarException("At least one top-level block must be present"); } @@ -118,10 +106,11 @@ public class RGrammarParser { return build.toRGrammar(); } catch (GrammarException gex) { - throw new GrammarException(String.format("Error in block (%s)", reader.getBlock()), gex); + String msg = String.format("Error in block (%s)", reader.getBlock()); + throw new GrammarException(msg, gex); } } catch (Exception ex) { - throw new GrammarException(String.format("Unknown error handling block"), ex); + throw new GrammarException("Unknown error handling block", ex); } } @@ -135,22 +124,16 @@ public class RGrammarParser { private static void handleBlock(RGrammarBuilder build, String block, int level) throws GrammarException { /* - * Discard empty blocks + * Discard empty blocks. */ - if (block.equals("")) - return; - - if (block.equals("\n")) - return; - - if (block.equals("\r\n")) + if (block.equals("") || block.matches("\\R")) return; int typeSep = block.indexOf(' '); if (typeSep == -1) { throw new GrammarException( - "A block must start with a type, followed by a space, then the rest of the block"); + "A block must start with a introducer, followed by a space, then the rest of the block"); } String blockType = block.substring(0, typeSep); @@ -164,10 +147,14 @@ public class RGrammarParser { } else if (blockType.equalsIgnoreCase("#")) { /* * Comment block. + * + * @Incomplete Attach these to the grammar builder so + * that they can be re-output during formatting. */ return; } else { - throw new GrammarException(String.format("Unknown block type: '%s'", blockType)); + String msg = String.format("Unknown block type: '%s'", blockType); + throw new GrammarException(msg); } } @@ -176,9 +163,8 @@ public class RGrammarParser { */ private static void handlePragmaBlock(String block, RGrammarBuilder build, int level) throws GrammarException { - try (BlockReader pragmaReader = new SimpleBlockReader(String.format( - TMPL_PRAGMA_BLOCK_DELIM, level), - new StringReader(block))) { + String dlm = String.format(TMPL_PRAGMA_BLOCK_DELIM, level); + try (BlockReader pragmaReader = new SimpleBlockReader(dlm, new StringReader(block))) { try { pragmaReader.forEachBlock((pragma) -> { String pragmaContents = pragma.contents; @@ -186,16 +172,16 @@ public class RGrammarParser { int pragmaSep = pragmaContents.indexOf(' '); if (pragmaSep == -1) { - throw new GrammarException("A pragma invocation must consist of the word pragma," - + " followed by a space, then the body of the pragma"); + String msg = "A pragma invocation must consist of the word pragma, followed by a space, then the body of the pragma"; + throw new GrammarException(msg); } String pragmaLeader = pragmaContents.substring(0, pragmaSep); String pragmaBody = pragmaContents.substring(pragmaSep + 1); if (!pragmaLeader.equalsIgnoreCase("pragma")) { - throw new GrammarException( - String.format("Illegal line leader in pragma block: '%s'", pragmaLeader)); + String msg = String.format("Illegal line leader in pragma block: '%s'", pragmaLeader); + throw new GrammarException(msg); } handlePragma(pragmaBody, build, level); @@ -203,14 +189,15 @@ public class RGrammarParser { } catch (GrammarException gex) { Block pragma = pragmaReader.getBlock(); - throw new GrammarException(String.format("Error in pragma: (%s)", pragma), gex); + String msg = String.format("Error in pragma: (%s)", pragma); + throw new GrammarException(msg, gex); } } catch (Exception ex) { throw new GrammarException("Unknown error handling pragma block", ex); } } - /*msg + /* * Handle an individual pragma in a block. */ private static void handlePragma(String pragma, RGrammarBuilder build, @@ -227,10 +214,12 @@ public class RGrammarParser { try { pragmas.get(pragmaName).accept(pragmaBody, build, level); } catch (GrammarException gex) { - throw new GrammarException(String.format("Error in '%s' pragma", pragmaName), gex); + String msg = String.format("Error in pragma '%s'", pragmaName); + throw new GrammarException(msg, gex); } } else { - throw new GrammarException(String.format("Unknown pragma named '%s'", pragmaName)); + String msg = String.format("Unknown pragma '%s'", pragmaName) + throw new GrammarException(msg); } } @@ -239,9 +228,8 @@ public class RGrammarParser { */ private static void handleRuleBlock(String ruleBlock, RGrammarBuilder build, int level) throws GrammarException { - try (BlockReader ruleReader = new SimpleBlockReader(String.format( - TMPL_RULEDECL_BLOCK_DELIM, level), - new StringReader(ruleBlock))) { + String msg = String.format(TMPL_RULEDECL_BLOCK_DELIM, level); + try (BlockReader ruleReader = new SimpleBlockReaderformat(msg, new StringReader(ruleBlock)) { try { if (ruleReader.hasNextBlock()) { /* @@ -267,8 +255,8 @@ public class RGrammarParser { build.finishRule(); } } catch (GrammarException gex) { - throw new GrammarException(String.format("Error in rule case (%s)", - ruleReader.getBlock()), gex); + String msg = String.format("Error in rule case (%s)", ruleReader.getBlock()); + throw new GrammarException(msg, gex); } } catch (Exception ex) { throw new GrammarException("Unknown error handling rule block", ex); |