src/syntax/trees/statements/list.ghul

1		namespace Syntax.Trees.Statements is
2
3		use Source
4
5		use Logging
6
7		class LIST: Trees.Statements.Statement, Collections.Iterable[Statement] is
8		_statements: Collections.List[Statement]
9		statements: Collections.Iterable[Statement] => _statements
10
11		// False when the final statement of this list reached the list's
12		// terminator without the `;` that would have ended it - the shape
13		// that makes a function-body tail an implicit return value. Set by
14		// the statement-list parser; every other path leaves it true.
15		last_was_terminated: bool public
16
17		// Stamped by compile-expressions on a function body list whose
18		// final statement is an implicit tail return: the walk judges the
19		// tail against the declared return type (including the async
20		// TASK[T] wrap) while scope and flow state are live.
21		function_tail: bool public => list_state.function_tail, = value is list_state.function_tail = value si
22
23		list_state: Syntax.Process.LIST_STATE field
24
25		is_tuple_literal: bool =>
26		let l = last in
27
28		if l? then
29		l.is_tuple_literal
30		else
31		false
32		fi
33
34		// Disposal bookkeeping recorded by compile-expressions, read by
35		// IL generation; contents owned by that pass.
36		dispose_state: Syntax.Process.LIST_DISPOSAL_STATE field
37
38		variables_to_dispose: Collections.List[Semantic.Symbols.Variable] => dispose_state.variables_to_dispose!
39
40		want_dispose: bool => dispose_state.want_dispose
41		provides_value: bool => true
42
43		init(location: LOCATION, statements: Collections.List[Statement]) is
44		super.init(location)
45
46		_statements = statements
47		last_was_terminated = true
48		si
49
50		iterator: Collections.Iterator[Statement] => _statements.iterator
51
52		is_empty: bool => _statements.count == 0
53
54		last: Statement? =>
55		if _statements.count == 0 then
56		null
57		else
58		_statements[_statements.count - 1]
59		fi
60
61		set_expected_type(expected_type: Semantic.Types.Type?, error_message: string?) =>
62		let l = last in
63
64		if l? then
65		l.set_expected_type(expected_type, error_message)
66		fi
67
68		clear_expected_type() =>
69		let l = last in
70
71		if l? then
72		l.clear_expected_type()
73		fi
74
75		add_variable_to_dispose(v: Semantic.Symbols.Variable) is
76		dispose_state.add(v)
77		si
78
79		clear() is
80		super.clear()
81		dispose_state.clear()
82		list_state.clear()
83		si
84
85		clear_outputs() is
86		super.clear_outputs()
87		dispose_state.clear()
88		si
89
90		// In-place replacement of the underlying statements.
91		replace_all(new_statements: Collections.Iterable[Statement]) is
92		_statements = Collections.LIST[Statement](new_statements)
93		si
94
95		add(statement: Statement) is
96		let grown = Collections.LIST[Statement]()
97		for s in _statements do
98		grown.add(s)
99		od
100		grown.add(statement)
101
102		_statements = grown
103		si
104
105		accept(visitor: Visitor) is
106		visitor.visit(self)
107		si
108
109		walk(visitor: Visitor) is
110		if !visitor.pre(self) then
111		for s in statements do
112		visitor.enter_node(s)
113		try
114		s.walk(visitor)
115		finally
116		visitor.leave_node(s)
117		yrt
118		od
119		fi
120
121		accept(visitor)
122		si
123		si
124		si