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1 package kawa.standard;
2 import gnu.mapping.*;
3 import java.io.PrintWriter  ;
4 import gnu.math.IntNum;
5 import gnu.kawa.functions.ObjectFormat;
6
7
8
9 public class TracedProcedure extends ProcedureN
10 {
11 public Procedure proc;
12 boolean enabled;
13
14 static int indentationStep = 2;
15 static Symbol curIndentSym = Symbol.makeUninterned("current-indentation");
16
17 public TracedProcedure (Procedure proc, boolean enable)
18 {
19 this.proc = proc;
20 this.enabled = enable;
21 String name = proc.getName();
22 if (name != null)
23 setName(name);
24 }
25
26 static void put(Object value, PrintWriter out)
27 {
28 try
29 {
30 if (! ObjectFormat.format(value, out, 50, true))
31 out.print("...");
32 }
33 catch (java.io.IOException ex)
34 {
35 out.print("<caught ");
36 out.print(ex);
37 out.print('>');
38 }
39 }
40
41 static void indent(int i, PrintWriter out)
42 {
43 while (--i >= 0)
44 out.print(' ');
45 }
46
47 public Object applyN(Object [] args) throws Throwable
48 {
49 if (enabled)
50 {
51 Environment env = Environment.getCurrent();
52 Location curIndentLoc = env.getLocation(curIndentSym);
53 Object oldIndent = curIndentLoc.get(null);
54 int curIndent;
55 if (! (oldIndent instanceof IntNum))
56 {
57 curIndent = 0;
58 curIndentLoc.set(IntNum.zero());
59 }
60 else
61 curIndent = ((IntNum) oldIndent).intValue();
62 PrintWriter out = OutPort.errDefault();
63 String name = getName();
64 if (name == null)
65 name = "??";
66
67 indent(curIndent, out);
69 out.print("call to ");
70 out.print(name);
71 int len = args.length;
72 out.print(" (");
73 for (int i = 0; i < len; i++)
74 {
75 if (i > 0)
76 out.print(' ');
77 put(args[i], out);
78 }
79 out.println(")");
80
81 CallContext context = CallContext.getInstance();
83 IntNum newIndentation = IntNum.make(curIndent+indentationStep);
84 Object result;
85 Object save = curIndentLoc.setWithSave(newIndentation, context);
86 try
87 {
88 result = proc.applyN(args);
89 }
90 catch (RuntimeException e)
91 {
92 indent(curIndent, out);
93 out.println("procedure " + name + " throws exception " + e);
94 throw e;
95 }
96 finally
97 {
98 curIndentLoc.setRestore(save, context);
99 }
100
101 indent(curIndent, out);
103 out.print("return from ");
104 out.print(name);
105 out.print(" => ");
106 put(result, out);
107 out.println();
108 return result;
109 }
110 return proc.applyN(args);
111 }
112
113 public static Procedure doTrace(Procedure proc, boolean enable)
114 {
115 if (proc instanceof TracedProcedure)
116 {
117 ((TracedProcedure) proc).enabled = enable;
118 return proc;
119 }
120 else
121 return new TracedProcedure(proc, enable);
122 }
123
124 public void print(java.io.PrintWriter ps)
125 {
126 ps.print ("#<procedure ");
127 String n = getName();
128 if (n == null)
129 ps.print ("<unnamed>");
130 else
131 ps.print (n);
132 ps.print(enabled? ", traced>" : ">");
133 }
134 }
135 |
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