From: steve <oksteev@...>
Date: 2008-02-04T13:14:45+09:00
Subject: Re: [QUIZ] Parsing JSON (#155)

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Here are some extra unit tests i wrote.  Let me know if you think any of
them are incorrect (per the spec):

def test_more_numbers
assert_equal(5, @parser.parse("5"))
assert_equal(-5, @parser.parse("-5"))
assert_equal 45.33, @parser.parse("45.33")
assert_equal 0.33, @parser.parse("0.33")
assert_equal 0.0, @parser.parse("0.0")
assert_equal 0, @parser.parse("0")
assert_raises(RuntimeError) { @parser.parse("-5.-4") }
assert_raises(RuntimeError) { @parser.parse("01234") }
assert_equal(0.2e1, @parser.parse("0.2E1"))
assert_equal(42e10, @parser.parse("42E10"))
end

def test_more_string
  assert_equal("abc\befg", @parser.parse(%Q{"abc\\befg"}))
  assert_equal("abc\nefg", @parser.parse(%Q{"abc\\nefg"}))
  assert_equal("abc\refg", @parser.parse(%Q{"abc\\refg"}))
  assert_equal("abc\fefg", @parser.parse(%Q{"abc\\fefg"}))
  assert_equal("abc\tefg", @parser.parse(%Q{"abc\\tefg"}))
  assert_equal("abc\\efg", @parser.parse(%Q{"abc\\\\efg"}))
  assert_equal("abc/efg", @parser.parse(%Q{"abc\\/efg"}))
end

def test_more_object_parsing
  assert_equal({'a'=>2,'b'=>4}, @parser.parse(%Q{{   "a" : 2 , "b":4 }}))
  assert_raises(RuntimeError) { @parser.parse(%Q{{   "a" : 2, }}) }
  assert_raises(RuntimeError) { @parser.parse(%Q{[   "a" , 2, ]}) }
end


On Feb 1, 2008 8:55 PM, Ruby Quiz <james@grayproductions.net> wrote:

> The three rules of Ruby Quiz:
>
> 1.  Please do not post any solutions or spoiler discussion for this quiz
> until
> 48 hours have passed from the time on this message.
>
> 2.  Support Ruby Quiz by submitting ideas as often as you can:
>
> http://www.rubyquiz.com/
>
> 3.  Enjoy!
>
> Suggestion:  A [QUIZ] in the subject of emails about the problem helps
> everyone
> on Ruby Talk follow the discussion.  Please reply to the original quiz
> message,
> if you can.
>
>
> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>
> There has been a lot of talk recently about parsing with Ruby.  We're
> seeing
> some parser generator libraries pop up that make the task that much easier
> and
> they've been stirring up interest.
>
> In honor of that, this week's Ruby Quiz is to write a parser for JSON.
>
> JSON turns out to turns out to be a great little example for writing
> parsers for
> two reasons.  First, it's pretty easy stuff.  You can hand-roll a JSON
> parser in
> under 100 lines of Ruby.  The second advantage is that the data format is
> wonderfully documented:
>
>        http://json.org/
>
> Since JSON is just a data format and Ruby supports all of the data types,
> I vote
> we just use Ruby itself as the abstract syntax tree produced by the parse.
>
> Feel free to show off your favorite parser generator, if you don't want to
> roll
> your own.  Anything goes.
>
> Here are a few tests to get you started:
>
>        require "test/unit"
>
>        class TestJSONParser < Test::Unit::TestCase
>          def setup
>            @parser = JSONParser.new
>          end
>
>          def test_keyword_parsing
>            assert_equal(true,  @parser.parse("true"))
>            assert_equal(false, @parser.parse("false"))
>            assert_equal(nil,   @parser.parse("null"))
>          end
>
>          def test_number_parsing
>            assert_equal(42,      @parser.parse("42"))
>            assert_equal(-13,     @parser.parse("-13"))
>            assert_equal(3.1415,  @parser.parse("3.1415"))
>            assert_equal(-0.01,   @parser.parse("-0.01"))
>
>            assert_equal(0.2e1,   @parser.parse("0.2e1"))
>            assert_equal(0.2e+1,  @parser.parse("0.2e+1"))
>            assert_equal(0.2e-1,  @parser.parse("0.2e-1"))
>            assert_equal(0.2E1,   @parser.parse("0.2e1"))
>          end
>
>          def test_string_parsing
>            assert_equal(String.new,          @parser.parse(%Q{""}))
>            assert_equal("JSON",              @parser.parse(%Q{"JSON"}))
>
>            assert_equal( %Q{nested "quotes"},
>                          @parser.parse('"nested \"quotes\""') )
>            assert_equal("\n",                @parser.parse(%Q{"\\n"}))
>            assert_equal( "a",
>                          @parser.parse(%Q{"\\u#{"%04X" % ?a}"}) )
>          end
>
>          def test_array_parsing
>            assert_equal(Array.new, @parser.parse(%Q{[]}))
>            assert_equal( ["JSON", 3.1415, true],
>                          @parser.parse(%Q{["JSON", 3.1415, true]}) )
>            assert_equal([1, [2, [3]]], @parser.parse(%Q{[1, [2, [3]]]}))
>          end
>
>          def test_object_parsing
>            assert_equal(Hash.new, @parser.parse(%Q{{}}))
>            assert_equal( {"JSON" => 3.1415, "data" => true},
>                          @parser.parse(%Q{{"JSON": 3.1415, "data": true}})
> )
>            assert_equal( { "Array"  => [1, 2, 3],
>                            "Object" => {"nested" => "objects"} },
>                          @parser.parse(<<-END_OBJECT) )
>            {"Array": [1, 2, 3], "Object": {"nested": "objects"}}
>            END_OBJECT
>          end
>
>          def test_parse_errors
>            assert_raise(RuntimeError) { @parser.parse("{") }
>            assert_raise(RuntimeError) { @parser.parse(%q{{"key": true
> false}}) }
>
>            assert_raise(RuntimeError) { @parser.parse("[") }
>            assert_raise(RuntimeError) { @parser.parse("[1,,2]") }
>
>            assert_raise(RuntimeError) { @parser.parse(%Q{"}) }
>            assert_raise(RuntimeError) { @parser.parse(%Q{"\\i"}) }
>
>            assert_raise(RuntimeError) { @parser.parse("$1,000") }
>            assert_raise(RuntimeError) { @parser.parse("1_000") }
>            assert_raise(RuntimeError) { @parser.parse("1K") }
>
>            assert_raise(RuntimeError) { @parser.parse("unknown") }
>          end
>        end
>
>

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