pegjs-strip is a utility for removing Javascript code fragments from the specified PEG.js grammar file.
The utility removes all code-related statements such as the initializer block, actions and labels. The semantic predicate &{<code>} and !{<code>} are replaced with &{return true;} or !{return false;} respectively.
By default, the utility does not strip comment blocks. To remove comments, --strip-comment option can be used.
Usage: pegjs-strip [options] file
Options:
-h, --help show this help.
--strip-comment Strip comments.
--keep-initializer Keep the initializer block.
--keep-action Keep actions.
--keep-label Keep labels.
--keep-semantic-predicate Keep semantic predicates.
The following grammar is from the PEG.js documentation.
start
= additive
additive
= left:multiplicative "+" right:additive { return left + right; }
/ multiplicative
multiplicative
= left:primary "*" right:multiplicative { return left * right; }
/ primary
primary
= integer
/ "(" additive:additive ")" { return additive; }
integer "integer"
= digits:[0-9]+ { return parseInt(digits.join(""), 10); }
To remove all the code in the grammar, just run the utility with the grammar file as the first argument. The result is then written to the standard output as follows.
$ pegjs-strip example.pegjs
start
= additive
additive
= multiplicative "+" additive
/ multiplicative
multiplicative
= primary "*" multiplicative
/ primary
primary
= integer
/ "(" additive ")"
integer "integer"
= [0-9]+
--keep-label option is available to leave all labels in the resulting output.
$ pegjs-strip --keep-label example.pegjs
start
= additive
additive
= left:multiplicative "+" right:additive
/ multiplicative
multiplicative
= left:primary "*" right:multiplicative
/ primary
primary
= integer
/ "(" additive:additive ")"
integer "integer"
= digits:[0-9]+