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Contents
# encoding: utf-8
module Crass
# Like {Scanner}, but for tokens!
class TokenScanner
attr_reader :current, :pos, :tokens
def initialize(tokens)
@tokens = tokens.to_a
reset
end
# Executes the given block, collects all tokens that are consumed during its
# execution, and returns them.
def collect
start = @pos
yield
@tokens[start...@pos] || []
end
# Consumes the next token and returns it, advancing the pointer. Returns
# `nil` if there is no next token.
def consume
@current = @tokens[@pos]
@pos += 1 if @current
@current
end
# Returns the next token without consuming it, or `nil` if there is no next
# token.
def peek
@tokens[@pos]
end
# Reconsumes the current token, moving the pointer back one position.
#
# http://www.w3.org/TR/2013/WD-css-syntax-3-20130919/#reconsume-the-current-input-token
def reconsume
@pos -= 1 if @pos > 0
end
# Resets the pointer to the first token in the list.
def reset
@current = nil
@pos = 0
end
end
end
Version data entries
43 entries across 39 versions & 16 rubygems