comment and keyword handling in treetop

May 8th, 2008 • Uncategorized

# whitespace
rule white
[ \r\t\n]+
end

# mandatory space
rule SPACE
(white / comment)+
end

# optional space
rule space
SPACE?
end

# anything but not white
rule non_white_char
!white .
end

# typical keyword rule
rule var_keyword
'var' !non_white_char
end

rule comment
comment_to_eol / multiline_comment
end

rule multiline_comment
'/*' (!'*/' . )* '*/'
end

rule comment_to_eol
# TODO find out why this doesn't work in specs
#'#' (!"\n" .)+ "\n"

'#' (!"\n" .)*
end

Tags: peg, ruby, treetop

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