Highlight Features

This version's main target is to optimize the performance.

Tested with dt0, the time spent on parser building reduced 26% (~130ms => ~95ms).

Highlight Features

• Add high-level resolver APIs: builder.priority/leftSA/rightSA.
• Add builder.use to apply custom decorators.
• builder.resolveRS/resolveRR support *+?.
• Provide versioned documentation.

Breaking Changes

• ParserBuilder.checkSymbols is now private, use options in ParserBuilder.build instead.
• Remove AdvancedBuilder.expand, make AdvancedBuilder extend ParserBuilder, they both implement IParserBuilder.

Breaking Changes

ParserBuilder.generateResolvers/checkConflicts is now private, and ParserBuilder.checkAll is removed. Use options in ParserBuilder.build instead.

Highlight Features

• Add debug option to AdvancedBuilder.expand.
• Auto resolve R-S conflicts when AdvancedBuilder.expand.
• Allow '*' as the next when resolve RS/RR conflicts.
• Optimize performance.

Highlight Features

Add ELR.AdvancedBuilder to support meta characters like +*? when defining grammar rules!

Highlight Features

• Add ASTNode.traverse and DefinitionContext.traverser to make it super easy to invoke a top-down traverse after the AST is built.
• Add ASTNode.$ to query children by its type name or literal value.

Highlight Features

• Add DefinicionContext.rollback so you can rollback global state when re-lex. (ELR parser only)
• Add parser.commit to commit existing changes to prevent re-lex. (ELR parser only)

Highlight Features

Introducing ELR(Expectational LR) Parser

• The ELR parser will actively use the Lexer to lex the input string to tokens according to the grammar rules.
• Re-Lex: If the lexed token can't be accepted, the ELR parser will try to restore & re-lex input.

Lexer

• Add Lexer.trimStart/clone/dryClone/take.

Highlight Features

• LR parser support conflict detection (for reduce-shift conflicts and reduce-reduce conflicts), and will try to auto resolve those conflicts by LR-1 peeking.
• Add ParserBuilder.generateResolver to generate code to manually resolve conflicts which can not be auto resolved.
• DFA will cache computed states on the fly to optimize performance. You can also use DFA.calculateAllStates to calculate and cache all states ahead of time.
• ASTNode can be serialized to a JSON object to co-work with other tools (e.g. compiler backend libs).

TODO

• Optimize errors and output.
• Add wiki and Chinese documents.
• Optimize test code.

CHANGELOG

For detailed information, see CHANGELOG.