lib/temple/filters/control_flow.rb
# frozen_string_literal: true module Temple module Filters # Control flow filter which processes [:if, condition, yes-exp, no-exp] # and [:block, code, content] expressions. # This is useful for ruby code generation with lots of conditionals. # # @api public class ControlFlow < Filter def on_if(condition, yes, no = nil) result = [:multi, [:code, "if #{condition}"], compile(yes)] while no && no.first == :if result << [:code, "elsif #{no[1]}"] << compile(no[2]) no = no[3] end result << [:code, 'else'] << compile(no) if no result << [:code, 'end'] result end def on_case(arg, *cases) result = [:multi, [:code, arg ? "case (#{arg})" : 'case']] cases.map do |c| condition, exp = c result << [:code, condition == :else ? 'else' : "when #{condition}"] << compile(exp) end result << [:code, 'end'] result end def on_cond(*cases) on_case(nil, *cases) end def on_block(code, exp) [:multi, [:code, code], compile(exp), [:code, 'end']] end end end end