src/syntax/parsers/definitions/property.ghul

1		namespace Syntax.Parsers.Definitions is
2		use IO.Std
3
4		use Source
5
6		use Logging
7
8		class PROPERTY(
9		identifier_parser: Parser[Trees.Identifiers.Identifier],
10		type_parser: Parser[Trees.TypeExpressions.TypeExpression],
11		modifier_list_parser: Parser[Trees.Modifiers.LIST],
12		body_parser: Parser[Trees.Bodies.Body]
13		): Base[Trees.Definitions.PROPERTY] is
14		super()
15
16		parse(context: CONTEXT) -> Trees.Definitions.PROPERTY is
17		let fail mut = false
18		let progress mut = false
19
20		try
21		if context.in_classy then
22		context.in_member = true
23		context.member_indent = context.location.start_column
24		else
25		context.in_global_function = true
26		context.global_indent = context.location.start_column
27		fi
28
29		let start = context.location
30		let name = identifier_parser.parse(context)
31		let type_expression: Trees.TypeExpressions.TypeExpression mut
32
33		if context.current.token == Lexical.TOKEN.COLON then
34		context.next_token()
35		progress = true
36
37		if let parsed = type_parser.parse(context) then
38		type_expression = parsed
39
40		if parsed.is_poisoned then
41		fail = true
42		fi
43		else
44		type_expression = Trees.TypeExpressions.INFER(context.location)
45		fail = true
46		fi
47		else
48		type_expression = Trees.TypeExpressions.INFER(context.location)
49		fi
50
51		let modifiers = modifier_list_parser.parse(context)!
52		let read_body: Trees.Bodies.Body? mut = null
53		let assign_body: Trees.Bodies.Body? mut = null
54		let setter_argument_name: Trees.Identifiers.Identifier? mut = null
55		let expect_semicolon mut = true
56
57		do
58		if context.current.token == Lexical.TOKEN.ASSIGN then
59		if setter_argument_name? then
60		context.error(context.location, "replacing assign")
61		fi
62
63		context.next_token()
64		progress = true
65
66		setter_argument_name = identifier_parser.parse(context)
67		expect_semicolon = context.current.token == Lexical.TOKEN.ARROW_FAT \/ context.current.token == Lexical.TOKEN.INNATE
68
69		try
70		assign_body = body_parser.parse(context)
71		catch ue: UNWIND_TO_MEMBER_EXCEPTION
72		assign_body = Trees.Bodies.NULL(context.location)
73		fail = true
74		yrt
75
76		if context.current.token == Lexical.TOKEN.COMMA then
77		context.next_token()
78		progress = true
79		else
80		if isa Trees.Bodies.NULL(assign_body) then
81		expect_semicolon = true
82		fi
83
84		break
85		fi
86		elif
87		context.current.token == Lexical.TOKEN.IS \/
88		context.current.token == Lexical.TOKEN.ARROW_FAT \/
89		context.current.token == Lexical.TOKEN.INNATE
90		then
91		expect_semicolon = context.current.token == Lexical.TOKEN.ARROW_FAT \/ context.current.token == Lexical.TOKEN.INNATE
92
93		if read_body? then
94		context.error(context.location, "replacing read")
95		fi
96
97		try
98		read_body = body_parser.parse(context)
99		catch ue: UNWIND_TO_MEMBER_EXCEPTION
100		read_body = Trees.Bodies.NULL(context.location)
101		fail = true
102		yrt
103
104		if context.current.token == Lexical.TOKEN.COMMA then
105		context.next_token()
106		progress = true
107		else
108		if isa Trees.Bodies.NULL(read_body) then
109		expect_semicolon = true
110		else
111		progress = true
112		fi
113
114		break
115		fi
116		elif context.current_token == Lexical.TOKEN.SEMICOLON then
117		break
118		elif context.at_inferred_terminator then
119		// a line break ends a bare declaration the same way
120		// a `;` does; the terminator check below reports it
121		break
122		elif context.current_token == Lexical.TOKEN.COMMA then
123		if read_body? then
124		context.error(context.location, "replacing read")
125		elif assign_body? then
126		context.error(context.location, "empty read body must precede write body")
127		else
128		progress = true
129		context.next_token()
130
131		read_body = Syntax.Trees.Bodies.NULL(context.current.location)
132		fi
133		else
134		if !fail then
135		context.error(context.location, "syntax error in property: unexpected token {context.current_token_name}")
136		fi
137
138		fail = true
139
140		// A function header damaged so that it reads as a
141		// property, `f n: int) -> int is`, still has its body
142		// after it. Read to a body opener on this line, so the
143		// body is kept rather than its statements being read
144		// one at a time as members.
145		while
146		!context.is_end_of_file /\
147		!context.current.first_on_line /\
148		context.current.token != Lexical.TOKEN.IS /\
149		context.current.token != Lexical.TOKEN.ARROW_FAT
150		do
151		context.next_token()
152		progress = true
153		od
154
155		if
156		!context.current.first_on_line /\
157		(context.current.token == Lexical.TOKEN.IS \/ context.current.token == Lexical.TOKEN.ARROW_FAT) /\
158		!read_body?
159		then
160		continue
161		fi
162
163		break
164		fi
165
166		expect_semicolon = true
167		od
168
169		if context.in_trait /\ read_body == null then
170		read_body = Trees.Bodies.NULL(context.location)
171		fi
172
173		let result =
174		Trees.Definitions.PROPERTY(
175		start::context.location,
176		type_expression,
177		name,
178		modifiers,
179		read_body,
180		setter_argument_name,
181		assign_body
182		)
183
184		if expect_semicolon then
185		if !fail \/ context.current.token == Lexical.TOKEN.SEMICOLON then
186		context.accept_terminator()
187		fi
188		fi
189
190		if fail /\ !progress then
191		debug_always("no progress parsing property at {context.location}")
192		IoC.CONTAINER.instance.watchdog.request_restart()
193
194		context.error(context.location, "syntax error in property: unexpected token {context.current_token_name}")
195		context.next_token()
196
197		throw UNWIND_BAD_PROPERTY_EXCEPTION(null)
198		fi
199
200		result.poison(fail)
201
202		return result
203		finally
204		context.in_member = false
205		yrt
206		si
207		si
208		si