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Java > Open Source Codes > polyglot > ext > jl > ast > Catch_c


1 package polyglot.ext.jl.ast;
2
3 import polyglot.ast.*;
4
5 import polyglot.util.*;
6 import polyglot.types.*;
7 import polyglot.visit.*;
8 import java.util.*;
9
10 /**
11  * A <code>Catch</code> represents one half of a <code>try-catch</code>
12  * statement. Specifically, the second half.
13  */
14 public class Catch_c extends Stmt_c implements Catch
15 {
16     protected Formal formal;
17     protected Block body;
18
19     public Catch_c(Position pos, Formal formal, Block body) {
20     super(pos);
21     this.formal = formal;
22     this.body = body;
23     }
24
25     /** Get the catchType of the catch block. */
26     public Type catchType() {
27         return formal.declType();
28     }
29
30     /** Get the formal of the catch block. */
31     public Formal formal() {
32     return this.formal;
33     }
34
35     /** Set the formal of the catch block. */
36     public Catch formal(Formal formal) {
37     Catch_c n = (Catch_c) copy();
38     n.formal = formal;
39     return n;
40     }
41
42     /** Get the body of the catch block. */
43     public Block body() {
44     return this.body;
45     }
46
47     /** Set the body of the catch block. */
48     public Catch body(Block body) {
49     Catch_c n = (Catch_c) copy();
50     n.body = body;
51     return n;
52     }
53
54     /** Reconstruct the catch block. */
55     protected Catch_c reconstruct(Formal formal, Block body) {
56     if (formal != this.formal || body != this.body) {
57         Catch_c n = (Catch_c) copy();
58         n.formal = formal;
59         n.body = body;
60         return n;
61     }
62
63     return this;
64     }
65
66     /** Visit the children of the catch block. */
67     public Node visitChildren(NodeVisitor v) {
68     Formal formal = (Formal) visitChild(this.formal, v);
69     Block body = (Block) visitChild(this.body, v);
70     return reconstruct(formal, body);
71     }
72
73     public Context enterScope(Context c) {
74         return c.pushBlock();
75     }
76
77     /** Type check the catch block. */
78     public Node typeCheck(TypeChecker tc) throws SemanticException {
79         TypeSystem ts = tc.typeSystem();
80
81     if (! catchType().isThrowable()) {
82         throw new SemanticException(
83         "Can only throw subclasses of \"" +
84         ts.Throwable() + "\".", formal.position());
85
86     }
87
88     return this;
89     }
90
91     public String JavaDoc toString() {
92     return "catch (" + formal + ") " + body;
93     }
94
95     /** Write the catch block to an output file. */
96     public void prettyPrint(CodeWriter w, PrettyPrinter tr) {
97     w.write("catch (");
98     printBlock(formal, w, tr);
99     w.write(")");
100     printSubStmt(body, w, tr);
101     }
102
103     public Term entry() {
104         return formal.entry();
105     }
106
107     public List acceptCFG(CFGBuilder v, List succs) {
108         v.visitCFG(formal, body.entry());
109         v.visitCFG(body, this);
110         return succs;
111     }
112 }
113
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