Line data Source code
1 : /* valaforstatement.vala
2 : *
3 : * Copyright (C) 2006-2010 Jürg Billeter
4 : *
5 : * This library is free software; you can redistribute it and/or
6 : * modify it under the terms of the GNU Lesser General Public
7 : * License as published by the Free Software Foundation; either
8 : * version 2.1 of the License, or (at your option) any later version.
9 :
10 : * This library is distributed in the hope that it will be useful,
11 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 : * Lesser General Public License for more details.
14 :
15 : * You should have received a copy of the GNU Lesser General Public
16 : * License along with this library; if not, write to the Free Software
17 : * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 : *
19 : * Author:
20 : * Jürg Billeter <j@bitron.ch>
21 : */
22 :
23 : using GLib;
24 :
25 : /**
26 : * Represents a for iteration statement in the source code.
27 : */
28 12590 : public class Vala.ForStatement : Loop, Statement {
29 9532 : private List<Expression> initializer = new ArrayList<Expression> ();
30 9532 : private List<Expression> iterator = new ArrayList<Expression> ();
31 :
32 : /**
33 : * Creates a new for statement.
34 : *
35 : * @param condition loop condition
36 : * @param body loop body
37 : * @param source_reference reference to source code
38 : * @return newly created for statement
39 : */
40 14298 : public ForStatement (Expression? condition, Block body, SourceReference? source_reference = null) {
41 4766 : base (condition, body, source_reference);
42 : }
43 :
44 : /**
45 : * Appends the specified expression to the list of initializers.
46 : *
47 : * @param init an initializer expression
48 : */
49 3078 : public void add_initializer (Expression init) {
50 3078 : init.parent_node = this;
51 3078 : initializer.add (init);
52 : }
53 :
54 : /**
55 : * Returns the list of initializers.
56 : *
57 : * @return initializer list
58 : */
59 0 : public unowned List<Expression> get_initializer () {
60 0 : return initializer;
61 : }
62 :
63 : /**
64 : * Appends the specified expression to the iterator.
65 : *
66 : * @param iter an iterator expression
67 : */
68 4769 : public void add_iterator (Expression iter) {
69 4769 : iter.parent_node = this;
70 4769 : iterator.add (iter);
71 : }
72 :
73 : /**
74 : * Returns the iterator.
75 : *
76 : * @return iterator
77 : */
78 0 : public unowned List<Expression> get_iterator () {
79 0 : return iterator;
80 : }
81 :
82 4442 : public override void accept (CodeVisitor visitor) {
83 4442 : visitor.visit_for_statement (this);
84 : }
85 :
86 4442 : public override void accept_children (CodeVisitor visitor) {
87 10166 : foreach (Expression init_expr in initializer) {
88 2862 : init_expr.accept (visitor);
89 2862 : visitor.visit_end_full_expression (init_expr);
90 : }
91 :
92 4442 : if (condition != null) {
93 4441 : condition.accept (visitor);
94 :
95 4441 : visitor.visit_end_full_expression (condition);
96 : }
97 :
98 13332 : foreach (Expression it_expr in iterator) {
99 4445 : it_expr.accept (visitor);
100 4445 : visitor.visit_end_full_expression (it_expr);
101 : }
102 :
103 4442 : body.accept (visitor);
104 : }
105 :
106 0 : public override void replace_expression (Expression old_node, Expression new_node) {
107 0 : base.replace_expression (old_node, new_node);
108 :
109 0 : for (int i=0; i < initializer.size; i++) {
110 0 : if (initializer[i] == old_node) {
111 0 : initializer[i] = new_node;
112 0 : new_node.parent_node = this;
113 : }
114 : }
115 0 : for (int i=0; i < iterator.size; i++) {
116 0 : if (iterator[i] == old_node) {
117 0 : iterator[i] = new_node;
118 0 : new_node.parent_node = this;
119 : }
120 : }
121 : }
122 :
123 4424 : public override bool check (CodeContext context) {
124 4424 : if (checked) {
125 0 : return !error;
126 : }
127 :
128 4424 : checked = true;
129 :
130 : // convert to simple loop
131 :
132 4424 : var block = new Block (source_reference);
133 :
134 : // initializer
135 10124 : foreach (var init_expr in initializer) {
136 2850 : block.add_statement (new ExpressionStatement (init_expr, init_expr.source_reference));
137 : }
138 :
139 : // do not generate if block if condition is always true
140 4424 : if (condition == null || condition.is_always_true ()) {
141 8843 : } else if (condition.is_always_false ()) {
142 : // do not generate if block if condition is always false
143 1 : body.insert_statement (0, new BreakStatement (condition.source_reference));
144 : } else {
145 : // condition
146 4421 : var if_condition = new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, condition, condition.source_reference);
147 4421 : var true_block = new Block (condition.source_reference);
148 4421 : true_block.add_statement (new BreakStatement (condition.source_reference));
149 4421 : var if_stmt = new IfStatement (if_condition, true_block, null, condition.source_reference);
150 4421 : body.insert_statement (0, if_stmt);
151 : }
152 :
153 : // iterator
154 4424 : var first_local = new LocalVariable (context.analyzer.bool_type.copy (), get_temp_name (), new BooleanLiteral (true, source_reference), source_reference);
155 4424 : block.add_statement (new DeclarationStatement (first_local, source_reference));
156 :
157 4424 : var iterator_block = new Block (source_reference);
158 13278 : foreach (var it_expr in iterator) {
159 4427 : iterator_block.add_statement (new ExpressionStatement (it_expr, it_expr.source_reference));
160 : }
161 :
162 4424 : var first_if = new IfStatement (new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, new MemberAccess.simple (first_local.name, source_reference), source_reference), iterator_block, null, source_reference);
163 4424 : body.insert_statement (0, first_if);
164 4424 : body.insert_statement (1, new ExpressionStatement (new Assignment (new MemberAccess.simple (first_local.name, source_reference), new BooleanLiteral (false, source_reference), AssignmentOperator.SIMPLE, source_reference), source_reference));
165 :
166 4424 : block.add_statement (new LoopStatement (body, source_reference));
167 :
168 4424 : unowned Block parent_block = (Block) parent_node;
169 4424 : parent_block.replace_statement (this, block);
170 :
171 4424 : if (!block.check (context)) {
172 0 : error = true;
173 : }
174 :
175 4424 : return !error;
176 : }
177 : }
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