Perform a Kleene transform of a grammar
Replace a rule with an EBNF form if it contains direct left or direct right recursion.
trkleene ?
trkleene refactors rules in a grammar with direct left or direct right
recursion. The program first reads from stdin the parse tree data of
grammar files(x). It then searches
the parse tree for the nodes identified by the XPath expression argument
or if none given, all parser and lexer rules in the grammar.
The XPath argument can select any node for the rule (e.g., the LHS symbol,
any RHS symbol, the colon in the rule, etc). The program will finally
replace the RHS of each rule selected with a "Kleene" version of the rule,
removing the recursion. The updated grammar(s) as parse tree data
is outputed to stdout.
trparse A.g4 | trkleene
trparse A.g4 | trkleene "//parserRuleSpec/RULE_REF[text()='packageOrTypeName']"
If you are running MSYS2 on Windows, you may notice that XPaths are not being processed by this command correctly. To avoid the Bash shell from altering XPaths, type export MSYS2_ARG_CONV_EXCL="*", then execute your command.
0.23.11 Fix trgen for st*.g4 grammars. Add template processing for target-specific files in a grammmar.
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Copyright (c) 2024 Ken Domino
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