39 lines
1014 B
Ruby
39 lines
1014 B
Ruby
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# Matches a special kind of regular expression that only ever matches one
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# character at a time. Useful members of this family are: <code>character
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# ranges, \\w, \\d, \\r, \\n, ...</code>
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#
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# Example:
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#
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# match('[a-z]') # matches a-z
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# match('\s') # like regexps: matches space characters
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#
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class Parslet::Atoms::Re < Parslet::Atoms::Base
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attr_reader :match, :re
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def initialize(match)
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super()
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@match = match.to_s
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@re = Regexp.new(self.match, Regexp::MULTILINE)
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@error_msgs = {
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:premature => "Premature end of input",
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:failed => "Failed to match #{match.inspect[1..-2]}"
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}
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end
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def try(source, context, consume_all)
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return succ(source.consume(1)) if source.matches?(@re)
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# No string could be read
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return context.err(self, source, @error_msgs[:premature]) \
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if source.chars_left < 1
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# No match
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return context.err(self, source, @error_msgs[:failed])
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end
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def to_s_inner(prec)
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match.inspect[1..-2]
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end
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end
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