require 'test/unit'
require 'rockit/dparser'

class ATestOperatorGrammar < Test::Unit::TestCase
  MaybeTestGrammar = Rockit::DParser::Grammar.new do
    start :M, [[:A, maybe(:Digit)]], ast(:M, 0, 1)
    term :A, ["a"]
    term :Digit, [/[0-9]+/]
  end

  def test_01_use_maybe_parser
    parser = MaybeTestGrammar.new_parser

    ast = parser.parse "a1"
    assert_equal("M", ast.name)
    assert_kind_of(parser.astclass_of_name(:M), ast)
    assert_equal(2, ast.num_children)
    assert_equal("a", ast[0])
    assert_equal("1", ast[1])    

    ast = parser.parse "a"
    assert_equal("M", ast.name)
    assert_kind_of(parser.astclass_of_name(:M), ast)
    assert_equal(2, ast.num_children)
    assert_equal("a", ast[0])
    assert_equal(nil, ast[1])    
  end

  OperatorTestGrammar = Rockit::DParser::Grammar.new do
    start :Str, [[:A, plus(:B), plus(:A), mult(:C), maybe(:D)]], 
      ast(:Str, 0, 1, 3, 4)
    term :A, ["a"]
    term :B, ["b"]
    term :C, ["c"]
    term :D, ["d"]
  end

  def test_02_use_parser
    parser = OperatorTestGrammar.new_parser
    ast = parser.parse "abbbac"
    assert_equal("Str", ast.name)
    assert_kind_of(parser.astclass_of_name(:Str), ast)
    assert_equal(4, ast.num_children)
    assert_equal("a", ast[0])
    assert_equal(["b", "b", "b"], ast[1])
    assert_equal(["c"], ast[2])
    assert_equal(nil, ast[3])
  end

  def test_03_use_parser
    parser = OperatorTestGrammar.new_parser
    ast = parser.parse "a b a c  c d"
    assert_equal("Str", ast.name)
    assert_kind_of(parser.astclass_of_name(:Str), ast)
    assert_equal(4, ast.num_children)
    assert_equal("a", ast[0])
    assert_equal(["b"], ast[1])
    assert_equal(["c", "c"], ast[2])
    assert_equal("d", ast[3])
  end
end