src/syntax/parsers/definitions/indexer.ghul

1		namespace Syntax.Parsers.Definitions is
2		use IO.Std;
3
4		use Source;
5
6		class INDEXER(
7		identifier_parser: Parser[Trees.Identifiers.Identifier],
8		type_parser: Parser[Trees.TypeExpressions.TypeExpression],
9		modifier_list_parser: Parser[Trees.Modifiers.LIST],
10		variable_parser: Parser[Trees.Variables.VARIABLE],
11		body_parser: Parser[Trees.Bodies.Body]
12		): Base[Trees.Definitions.INDEXER] is
13		description: string => "indexer";
14
15		super();
16
17		parse(context: CONTEXT) -> Trees.Definitions.INDEXER? is
18		let name: Trees.Identifiers.Identifier? mut = null;
19		let start = context.location;
20
21		if context.current.token == Lexical.TOKEN.IDENTIFIER then
22		name = identifier_parser.parse(context);
23		fi
24
25		if !context.next_token(Lexical.TOKEN.SQUARE_OPEN) then
26		return null;
27		fi
28
29		let index_argument = variable_parser.parse(context);
30
31		let fail mut = !context.next_token(Lexical.TOKEN.SQUARE_CLOSE);
32
33		let type_expression: Trees.TypeExpressions.TypeExpression mut;
34
35		if !fail \/ context.current.token == Lexical.TOKEN.COLON then
36		context.next_token();
37		type_expression = type_parser.parse(context)!;
38
39		else
40		type_expression = Trees.TypeExpressions.INFER(context.location);
41		fi
42
43		let modifiers = modifier_list_parser.parse(context)!;
44		let read_body: Trees.Bodies.Body? mut = null;
45		let assign_body: Trees.Bodies.Body? mut = null;
46		let setter_argument_name: Trees.Identifiers.Identifier? mut = null;
47		let expect_semicolon mut = true;
48
49		let progress mut = false;
50
51		do
52		if fail then break ; fi
53
54		if context.current.token == Lexical.TOKEN.ASSIGN then
55		if setter_argument_name? then
56		context.error(context.location, "replacing assign");
57		fi
58		context.next_token();
59		progress = true;
60		setter_argument_name = identifier_parser.parse(context);
61		expect_semicolon = context.current.token != Lexical.TOKEN.COMMA /\ context.current.token != Lexical.TOKEN.IS;
62		assign_body = body_parser.parse(context);
63		if context.current.token == Lexical.TOKEN.COMMA then
64		context.next_token();
65		else
66		break;
67		fi
68		elif context.current.token == Lexical.TOKEN.IS \/ context.current.token == Lexical.TOKEN.ARROW_FAT then
69		expect_semicolon = context.current.token == Lexical.TOKEN.ARROW_FAT;
70		if read_body? then
71		context.error(context.location, "replacing read");
72		fi
73		read_body = body_parser.parse(context);
74		if context.current.token == Lexical.TOKEN.COMMA then
75		progress = true;
76		context.next_token();
77		else
78		break;
79		fi
80		elif context.current_token == Lexical.TOKEN.SEMICOLON then
81		break;
82		elif context.current_token == Lexical.TOKEN.COMMA then
83		if read_body? then
84		context.error(context.location, "replacing read");
85		elif assign_body? then
86		context.error(context.location, "empty read body must precede write body");
87		else
88		progress = true;
89		context.next_token();
90
91		read_body = Syntax.Trees.Bodies.NULL(context.current.location);
92		fi
93		else
94		if !fail then
95		context.error(context.location, "unexpected input in indexer");
96		fi
97
98		fail = true;
99
100		break;
101		fi
102
103		if !progress then
104		Std.error.write_line("no progress in indexer: {context.current_token_name}");
105		return null;
106		fi
107
108		expect_semicolon = true;
109		od
110
111		if context.in_trait /\ read_body == null then
112		read_body = Trees.Bodies.NULL(context.location);
113		fi
114
115		let result: Trees.Definitions.INDEXER? mut = null;
116
117		if index_argument? then
118		result =
119		Trees.Definitions.INDEXER(
120		start::context.location,
121		name,
122		index_argument,
123		type_expression,
124		modifiers,
125		read_body,
126		setter_argument_name,
127		assign_body
128		);
129		fi
130
131		if expect_semicolon then
132		context.next_token(Lexical.TOKEN.SEMICOLON);
133		fi
134
135		return result;
136		si
137		si
138		si