Hi Groovy-Dev Here’s another update on the progress on the Antlr4 parser, as maintained on https://github.com/jespersm/groovy.git (in the antlr4 branch). To play with it, try:
$ git clone -b antlr4 https://jespe...@github.com/jespersm/groovy.git $ cd groovy $ gradle -PuseAntlr4=true console I’ve fixed a number of issues: Support method pointer operator Attributes/method/property names as strings/gstrings Real support for unary plus and minus (mimics old parser’s behaviour) Compilation units not ending with semicolon or newline Slashy strings could span lines, confusing division statements and comments I can now explore the new grammar and AST building using the Console, which is fun, but it’s very easy to find unsupported constructs. Mapping out the full Groovy grammar from the documentation alone is quite a task. Just today, I discovered lacking support for ‘assert’ and for ’super’-calls. The smaller issues currently are: assert super() Full Unicode letter support for identifiers Support identifiers as property names and map literal entry names The bigger issue is with converting the ASTBuilder to pure Java, a task I havn’t started yet. Actually, this poses a different question for AST generation: Whether to switch from tree-walking the parse tree (so whole tree must be kept in memory), to the listener-based approach, where the AST is built mostly bottom-up, ensuring smaller memory footprint. So you can help me with a couple of answers: Memory: Is this an issue I should be focusing on — and is there a test to baseline against? I’ve discovered a small issue with unary syntax. Currently, nested unary expressions are not supported without parenthesis: Try e.g. - -1 or + -1. Is this intentional, or just an artifact of the precedence-refactored Java grammar? -Jesper
