| // Taken from "tool-testsuite/test/org/antlr/v4/test/tool/TestXPath.java" |
| // Builds ExprLexer.py and ExprParser.py |
| |
| grammar Expr; |
| prog: func+ ; |
| func: 'def' ID '(' arg (',' arg)* ')' body ; |
| body: '{' stat+ '}' ; |
| arg : ID ; |
| stat: expr ';' # printExpr |
| | ID '=' expr ';' # assign |
| | 'return' expr ';' # ret |
| | ';' # blank |
| ; |
| expr: expr ('*'|'/') expr # MulDiv |
| | expr ('+'|'-') expr # AddSub |
| | primary # prim |
| ; |
| primary |
| : INT # int |
| | ID # id |
| | '(' expr ')' # parens |
| ; |
| MUL : '*' ; // assigns token name to '*' used above in grammar |
| DIV : '/' ; |
| ADD : '+' ; |
| SUB : '-' ; |
| RETURN : 'return' ; |
| ID : [a-zA-Z]+ ; // match identifiers |
| INT : [0-9]+ ; // match integers |
| NEWLINE:'\r'? '\n' -> skip; // return newlines to parser (is end-statement signal) |
| WS : [ \t]+ -> skip ; // toss out whitespace |
