lib/sass/repl.rb
require 'readline' module Sass # Runs a SassScript read-eval-print loop. # It presents a prompt on the terminal, # reads in SassScript expressions, # evaluates them, # and prints the result. class Repl # @param options [{Symbol => Object}] An options hash. def initialize(options = {}) @options = options end # Starts the read-eval-print loop. def run environment = Environment.new environment.set_var('important', Script::String.new('!important')) @line = 0 loop do @line += 1 unless text = Readline.readline('>> ') puts return end Readline::HISTORY << text parse_input(environment, text) end end private def parse_input(environment, text) case text when Script::MATCH name = $1 guarded = $2 == '||=' val = Script::Parser.parse($3, @line, text.size - $3.size) unless guarded && environment.var(name) environment.set_var(name, val.perform(environment)) end p environment.var(name) else p Script::Parser.parse(text, @line, 0).perform(environment) end rescue Sass::SyntaxError => e puts "SyntaxError: #{e.message}" if @options[:trace] e.backtrace.each do |e| puts "\tfrom #{e}" end end end end end