1  # frozen_string_literal: true
   2 
   3  require "test_helper"
   4 
   5 
   6  module Umu
   7 
   8  module Test
   9 
  10  module Grammar
  11 
  12  module CoreLanguage
  13 
  14  module Declaration
  15 
  16  class RecursiveTest < Minitest::Test
  17  =begin
  18  <recursive-declaration> ::=
  19      FUN REC <pattern> "=" <binding> { AND <binding> } ;
  20 
  21  <binding> ::= ID "=" <function-body> ;
  22 
  23  /* <function-body> ::= ... ;  See FunctionTest */
  24  =end
  25      def setup
  26          @interp = Api.setup_interpreter
  27      end
  28 
  29 
  30      def test_recursive
  31          interp = Api.eval_decls @interp, <<-EOS
  32              fun rec fact = x ->
  33                  if x <= 1 then
  34                      1
  35                  else
  36                      x * fact (x - 1)
  37              EOS
  38 
  39          value = Api.eval_expr interp, "fact 1"
  40          assert_instance_of VCAN::Int, value
  41          assert_equal       1,         value.val
  42 
  43          value = Api.eval_expr interp, "fact 3"
  44          assert_instance_of VCAN::Int, value
  45          assert_equal       6,         value.val
  46      end
  47 
  48 
  49      def test_mutual_recursive
  50          interp = Api.eval_decls @interp, <<-EOS
  51              fun rec even? = x -> if x == 0 then TRUE  else odd?  (x - 1)
  52              and     odd?  = x -> if x == 0 then FALSE else even? (x - 1)
  53              EOS
  54 
  55          value = Api.eval_expr interp, "even? 2"
  56          assert_instance_of VCA::Bool, value
  57          assert_equal       true,      value.val
  58 
  59          value = Api.eval_expr interp, "even? 3"
  60          assert_instance_of VCA::Bool, value
  61          assert_equal       false,      value.val
  62 
  63          value = Api.eval_expr interp, "odd? 2"
  64          assert_instance_of VCA::Bool, value
  65          assert_equal       false,     value.val
  66 
  67          value = Api.eval_expr interp, "odd? 3"
  68          assert_instance_of VCA::Bool, value
  69          assert_equal       true,      value.val
  70      end
  71 
  72 
  73      def test_should_not_be_duplicated_function_names
  74          assert_raises(X::SyntaxError) do
  75              Api.eval_decls @interp, <<-EOS
  76                  fun rec f = x -> f 3
  77                  and     f = x -> f 4
  78                  EOS
  79          end
  80      end
  81  end
  82 
  83  end # Umu::Test::Grammar::CoreLanguage::Declaration
  84 
  85  end # Umu::Test::Grammar::CoreLanguage
  86 
  87  end # Umu::Test::Grammar
  88 
  89  end # Umu::Test
  90 
  91  end # Umu