1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
/* ____ ____ ____ ____ ______ *\
** / __// __ \/ __// __ \/ ____/ SOcos COmpiles Scala **
** __\_ \/ /_/ / /__/ /_/ /\_ \ (c) 2002, LAMP/EPFL **
** /_____/\____/\___/\____/____/ **
** **
** $Id$
\* */
package scalac.transformer.matching;
import scalac.*;
import scalac.ast.*;
import scalac.atree.AConstant;
import scalac.symtab.*;
import PatternNode.*;
import Tree.*;
import scalac.util.Name ;
import scalac.util.Names ;
//import scalac.ast.printer.TextTreePrinter ;
import java.util.Vector ;
import java.util.Iterator ;
/** Matthias' algebraic pattern matcher, with some things factored out
* @author Matthias Zenger, Burak Emir
*/
public class AlgebraicMatcher extends PatternMatcher {
PartialMatcher _m;
/** constructor
*/
public AlgebraicMatcher( Unit unit ) {
super( unit );
this.delegateSequenceMatching = true;
this.optimize = false;
}
/** constructs an algebraic pattern matcher from cases
*/
public void construct( PartialMatcher m, Tree[] cases) {
construct(m, cases, true);
}
/** constructs an algebraic pattern matcher from cases
*/
public void construct( PartialMatcher m, Tree[] cases, boolean doBinding) {
this._m = m;
super.initialize( _m.selector, _m.owner, _m.resultType, doBinding );
for( int i = 0; i < cases.length; i++ ) {
enter( cases[ i ] );//(CaseDef) cases[i], i);
}
if (unit.global.log()) {
unit.global.log("internal pattern matching structure");
print();
}
_m.tree = toTree();
}
/** initializes this AlgebraicMatcher, see Matcher.initialize
void initialize() {
}
*/
boolean isStarApply( Tree.Apply tree ) {
Symbol params[] = tree.fun.type.valueParams();
//System.err.println( tree.fun.type.resultType().symbol() );
return (tree.args.length == 1)
&& (tree.type.symbol().flags & Modifiers.CASE) != 0
&& params.length > 0
&& (params[params.length-1].flags & Modifiers.REPEATED) != 0;
}
//////////// generator methods
public Tree toTree() {
Tree[] ts = {
gen.ValDef(root.symbol(), _m.selector ),
gen.ValDef(resultVar,
gen.mkDefaultValue(_m.pos, resultVar.info()) )};
Tree res = gen.If( toTree(root.and),
gen.Ident( _m.pos, resultVar ),
cf.ThrowMatchError( _m.pos, _m.resultType ));
/*
gen.If(
_m.pos,
toTree(root.and),
gen.Ident( _m.pos, resultVar ),
cf.ThrowMatchError( _m.resultType ));
*/
return gen.mkBlock(_m.pos, ts, res);
}
protected Tree toTree(PatternNode node, Tree selector) {
//System.err.println("AM.toTree called"+node);
if (node == null)
return gen.mkBooleanLit(_m.pos, false);
switch (node) {
case SeqContainerPat( _, _ ):
return callSequenceMatcher( node,
selector );
default:
return super.toTree( node, selector );
}
}
/** collects all sequence patterns and returns the default
*/
PatternNode collectSeqPats( PatternNode node,
Vector seqPatNodes,
Vector bodies ) {
PatternNode defaultNode = null;
do {
if( node == null )
break;// defaultNode = node;
else
switch( node ) {
case SeqContainerPat( _, _ ):
seqPatNodes.add( node );
bodies.add( toTree( node.and ) );
node = node.or;
break;
default:
defaultNode = node;
}
} while (defaultNode == null) ;
return defaultNode;
}
Tree callSequenceMatcher( PatternNode node,
Tree selector) {
/* ???????????????????????? necessary to test whether is a Seq?
gen.If(selector.pos,
maybe cf.And( cf.Is(selector, seqpat.type())
...
*/
// translate the _.and subtree of this SeqContainerPat
Vector seqPatNodes = new Vector();
Vector bodies = new Vector();
PatternNode defaultNode = collectSeqPats( node,
seqPatNodes,
bodies );
Tree defaultCase = toTree( defaultNode, selector );
SequenceMatcher wordRec = new SequenceMatcher(unit);
PartialMatcher m = new PartialMatcher( _m.owner,
selector,
defs.BOOLEAN_TYPE() );
Tree pats[] = new Tree[ seqPatNodes.size() ];
Tree body[] = new Tree[ seqPatNodes.size() ];
Object tmp[] = bodies.toArray();
int j = 0;
for( Iterator it = seqPatNodes.iterator();
it.hasNext();) {
pats[ j ] = ((SeqContainerPat) it.next()).seqpat;
body[ j ] = (Tree) tmp[j];
j++;
}
//Tree defaultTree = toTree( node.or, selector ); // cdef.body ;
wordRec.construct( m, pats, body, defaultCase, doBinding );
//_m.defs.addAll( m.defs );
return m.tree;
}
}
|
