rubyx/lib/parslet/atoms/re.rb

39 lines
1014 B
Ruby

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