Add JSON parser test case

spec/json_types.d

@@ -0,0 +1,63 @@
+class JSONValue
+{
+}
+
+class JSONObject : JSONValue
+{
+    JSONValue[string] value;
+
+    this()
+    {
+    }
+
+    this(JSONValue[string] value)
+    {
+        this.value = value;
+    }
+}
+
+class JSONArray : JSONValue
+{
+    JSONValue[] value;
+
+    this()
+    {
+    }
+
+    this(JSONValue[] value)
+    {
+        this.value = value;
+    }
+}
+
+class JSONNumber : JSONValue
+{
+    double value;
+
+    this(double value)
+    {
+        this.value = value;
+    }
+}
+
+class JSONString : JSONValue
+{
+    string value;
+
+    this(string value)
+    {
+        this.value = value;
+    }
+}
+
+class JSONTrue : JSONValue
+{
+}
+
+class JSONFalse : JSONValue
+{
+}
+
+class JSONNull : JSONValue
+{
+}

spec/propane_spec.rb

@@ -334,4 +334,190 @@ EOF
     expect(results.stderr).to eq ""
     expect(results.status).to eq 0
   end
+
+  it "allows creating a JSON parser" do
+    write_grammar <<EOF
+<<
+    import std.math;
+    import json_types;
+    string string_value;
+>>
+
+ptype JSONValue;
+ptype array = JSONValue[];
+ptype dict = JSONValue[string];
+ptype string = string;
+
+drop /\\s+/;
+token lbrace /\\{/;
+token rbrace /\\}/;
+token lbracket /\\[/;
+token rbracket /\\]/;
+token comma /,/;
+token colon /:/;
+token number /-?(0|[1-9][0-9]*)(\\.[0-9]+)?([eE][-+]?[0-9]+)?/ <<
+    double n;
+    bool negative;
+    size_t i = 0u;
+    if (match[i] == '-')
+    {
+        negative = true;
+        i++;
+    }
+    while ('0' <= match[i] && match[i] <= '9')
+    {
+        n *= 10.0;
+        n += (match[i] - '0');
+        i++;
+    }
+    if (match[i] == '.')
+    {
+        i++;
+        double mult = 0.1;
+        while ('0' <= match[i] && match[i] <= '9')
+        {
+            n += mult * (match[i] - '0');
+            mult /= 10.0;
+            i++;
+        }
+    }
+    if (match[i] == 'e' || match[i] == 'E')
+    {
+        bool exp_negative;
+        i++;
+        if (match[i] == '-')
+        {
+            exp_negative = true;
+            i++;
+        }
+        else if (match[i] == '+')
+        {
+            i++;
+        }
+        long exp;
+        while ('0' <= match[i] && match[i] <= '9')
+        {
+            exp *= 10;
+            exp += (match[i] - '0');
+            i++;
+        }
+        if (exp_negative)
+        {
+            exp = -exp;
+        }
+        n = pow(n, exp);
+    }
+    if (negative)
+    {
+        n = -n;
+    }
+    $$ = new JSONNumber(n);
+>>
+token true <<
+  $$ = new JSONTrue();
+>>
+token false <<
+  $$ = new JSONFalse();
+>>
+token null <<
+  $$ = new JSONNull();
+>>
+/"/ <<
+  $mode(string);
+  string_value = "";
+>>
+string: token string (string) /"/ <<
+  $$ = string_value;
+  $mode(default);
+>>
+string: /\\\\"/ <<
+  string_value ~= "\\"";
+>>
+string: /\\\\\\\\/ <<
+  string_value ~= "\\\\";
+>>
+string: /\\\\\\// <<
+  string_value ~= "/";
+>>
+string: /\\\\b/ <<
+  string_value ~= "\\b";
+>>
+string: /\\\\f/ <<
+  string_value ~= "\\f";
+>>
+string: /\\\\n/ <<
+  string_value ~= "\\n";
+>>
+string: /\\\\r/ <<
+  string_value ~= "\\r";
+>>
+string: /\\\\t/ <<
+  string_value ~= "\\t";
+>>
+string: /\\\\u[0-9a-fA-F]{4}/ <<
+  /* Not actually going to encode the code point for this example... */
+  string_value ~= "{" ~ match[2..6] ~ "}";
+>>
+string: /[^\\\\]/ <<
+  string_value ~= match;
+>>
+Start -> Value <<
+  $$ = $1;
+>>
+Value -> string <<
+  $$ = new JSONString($1);
+>>
+Value -> number <<
+  $$ = $1;
+>>
+Value -> Object <<
+  $$ = $1;
+>>
+Value -> Array <<
+  $$ = $1;
+>>
+Value -> true <<
+  $$ = $1;
+>>
+Value -> false <<
+  $$ = $1;
+>>
+Value -> null <<
+  $$ = $1;
+>>
+Object -> lbrace rbrace <<
+  $$ = new JSONObject();
+>>
+Object -> lbrace KeyValues rbrace <<
+  $$ = new JSONObject($2);
+>>
+KeyValues (dict) -> KeyValue <<
+  $$ = $1;
+>>
+KeyValues -> KeyValues comma KeyValue <<
+  foreach (key, value; $3)
+  {
+    $1[key] = value;
+  }
+  $$ = $1;
+>>
+KeyValue (dict) -> string colon Value <<
+  $$ = [$1: $3];
+>>
+Array -> lbracket rbracket <<
+  $$ = new JSONArray();
+>>
+Array -> lbracket Values rbracket <<
+  $$ = new JSONArray($2);
+>>
+Values (array) -> Value <<
+  $$ = [$1];
+>>
+Values -> Values comma Value <<
+  $$ = $1 ~ [$3];
+>>
+EOF
+    build_parser
+    compile("spec/test_parsing_json.d", "spec/json_types.d")
+  end
 end

spec/test_parsing_json.d

@@ -0,0 +1,55 @@
+import testparser;
+import std.stdio;
+import json_types;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = ``;
+    auto parser = new Testparser.Parser(input);
+    assert(parser.parse());
+
+    input = `{}`;
+    parser = new Testparser.Parser(input);
+    assert(parser.parse());
+    assert(cast(JSONObject)parser.result);
+
+    input = `[]`;
+    parser = new Testparser.Parser(input);
+    assert(parser.parse());
+    assert(cast(JSONArray)parser.result);
+
+    input = `-45.6`;
+    parser = new Testparser.Parser(input);
+    assert(parser.parse());
+    assert(cast(JSONNumber)parser.result);
+    assert((cast(JSONNumber)parser.result).value == -45.6);
+
+    input = `2E-2`;
+    parser = new Testparser.Parser(input);
+    assert(parser.parse());
+    assert(cast(JSONNumber)parser.result);
+    assert((cast(JSONNumber)parser.result).value == 0.02);
+
+    input = `{"hi":true}`;
+    parser = new Testparser.Parser(input);
+    assert(parser.parse());
+    assert(cast(JSONObject)parser.result);
+    JSONObject o = cast(JSONObject)parser.result;
+    assert(o.value["hi"]);
+    assert(cast(JSONTrue)o.value["hi"]);
+
+    input = `{"ff": false, "nn": null}`;
+    parser = new Testparser.Parser(input);
+    assert(parser.parse());
+    assert(cast(JSONObject)parser.result);
+    o = cast(JSONObject)parser.result;
+    assert(o.value["ff"]);
+    assert(cast(JSONFalse)o.value["ff"]);
+    assert(o.value["nn"]);
+    assert(cast(JSONNull)o.value["nn"]);
+}