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1
4 package kawa.lang;
5 import gnu.mapping.*;
6 import gnu.expr.*;
7 import gnu.text.SourceMessages;
8 import gnu.lists.*;
9
10
11
12 public class Eval extends Procedure1or2
13 {
14 public static final Eval eval = new Eval();
15 static { eval.setName("eval"); }
16
17 final static String  evalFunctionName = "atEvalLevel";
18
19 public static void eval (Object sexpr, Environment env, CallContext ctx)
20 throws Throwable
21 {
22 PairWithPosition body;
23 if (sexpr instanceof PairWithPosition)
24 body = new PairWithPosition((PairWithPosition) sexpr,
25 sexpr, LList.Empty);
26 else
27 {
28 body = new PairWithPosition(sexpr, LList.Empty);
29 body.setFile("<eval>");
30 }
31 evalBody(body, env, new SourceMessages(), ctx);
32 }
33
34 public static Object evalBody (Object body, Environment env,
35 SourceMessages messages)
36 throws Throwable
37 {
38 CallContext ctx = CallContext.getInstance();
39 int oldIndex = ctx.startFromContext();
40 try
41 {
42 evalBody(body, env, messages, ctx);
43 return ctx.getFromContext(oldIndex);
44 }
45 catch (Throwable ex)
46 {
47 ctx.cleanupFromContext(oldIndex);
48 throw ex;
49 }
50 }
51
52 public static Object eval (Object sexpr, Environment env)
53 throws Throwable
54 {
55 CallContext ctx = CallContext.getInstance();
56 int oldIndex = ctx.startFromContext();
57 try
58 {
59 eval(sexpr, env, ctx);
60 return ctx.getFromContext(oldIndex);
61 }
62 catch (Throwable ex)
63 {
64 ctx.cleanupFromContext(oldIndex);
65 throw ex;
66 }
67 }
68
69 public static void evalBody (Object body, Environment env,
70 SourceMessages messages, CallContext ctx)
71 throws Throwable
72 {
73 Language language = Language.getDefaultLanguage();
74 Environment saveGlobalEnv = Environment.getCurrent();
75 try
76 {
77 if (env != saveGlobalEnv)
78 Environment.setCurrent(env);
79 Translator tr = new Translator(language, messages);
80 tr.immediate = true;
81 ModuleExp mod = tr.pushNewModule((String ) null);
82 Compilation save_comp = Compilation.getCurrent();
83 try
84 {
85 Compilation.setCurrent(tr);
86 int first = tr.formStack.size();
87 tr.scanBody(body, mod, false);
88 tr.firstForm = first;
89 tr.finishModule(mod);
90 }
91 finally
92 {
93 Compilation.setCurrent(save_comp);
94 }
95
96 if (body instanceof PairWithPosition)
97 mod.setFile(((PairWithPosition) body).getFileName());
98 mod.setName (evalFunctionName);
99 ModuleExp.evalModule(env, ctx, tr, null, null);
100 if (messages.seenErrors())
101 throw new RuntimeException ("invalid syntax in eval form:\n"
102 + messages.toString(20));
103 }
104 finally
105 {
106 if (env != saveGlobalEnv)
107 Environment.setCurrent(saveGlobalEnv);
108 }
109 }
110
111 public Object apply1 (Object arg1)
112 throws Throwable
113 {
114 return eval (arg1, Environment.user ());
115 }
116
117 public Object apply2 (Object arg1, Object arg2)
118 throws Throwable
119 {
120 return eval (arg1, (Environment) arg2);
121 }
122
123 public void apply (CallContext ctx)
124 throws Throwable
125 {
126 Procedure.checkArgCount(this, ctx.count);
127 Object exp = ctx.getNextArg();
128 Environment env;
129 env = (Environment) ctx.getNextArg(null);
130 if (env == null)
131 env = Environment.user();
132 ctx.lastArg();
133 eval(exp, env, ctx);
134 }
135 }
136 |
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