def process_iter(exp)
call = process exp.shift
var = process exp.shift
body = process exp.shift
var = s(:dasgn_curr, Unique.next) if var.nil?
assert_type call, :call
if call[2] != :each then
call.shift
lhs = call.shift
method_name = call.shift
case method_name
when :downto then
var.shift
start_value = lhs
finish_value = call.pop.pop
var_name = var.shift
body.find_and_replace_all(:dvar, :lvar)
result = s(:dummy,
s(:lasgn, var_name, start_value),
s(:while,
s(:call, s(:lvar, var_name), :>=,
s(:arglist, finish_value)),
s(:block,
body,
s(:lasgn, var_name,
s(:call, s(:lvar, var_name), :-,
s(:arglist, s(:lit, 1))))), true))
when :upto then
var.shift
start_value = lhs
finish_value = call.pop.pop
var_name = var.shift
body.find_and_replace_all(:dvar, :lvar)
result = s(:dummy,
s(:lasgn, var_name, start_value),
s(:while,
s(:call, s(:lvar, var_name), :<=,
s(:arglist, finish_value)),
s(:block,
body,
s(:lasgn, var_name,
s(:call, s(:lvar, var_name), :+,
s(:arglist, s(:lit, 1))))), true))
when :define_method then
var.find_and_replace_all(:dasgn_curr, :args)
body.find_and_replace_all(:dvar, :lvar)
result = s(:block, var, body)
else
result = s(:iter, s(:call, lhs, method_name, call.shift), var, body)
end
else
if var.nil? then
var = s(:lvar, Unique.next)
end
s(:iter, call, var, body)
end
end