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1
4 package kawa.standard;
5 import kawa.lang.*;
6 import gnu.expr.*;
7 import gnu.bytecode.ClassType;
8 import gnu.mapping.*;
9 import gnu.lists.*;
10
11 public class define_syntax extends Syntax
12 {
13 public static final define_syntax define_macro
14 = new define_syntax("%define-macro", false);
15
16 public static final define_syntax define_syntax
17 = new define_syntax("%define-syntax", true);
18
19 public define_syntax ()
20 {
21 this.hygienic = true;
22 }
23
24 public define_syntax (Object  name, boolean hygienic)
25 {
26 super(name);
27 this.hygienic = hygienic;
28 }
29
30 static ClassType typeMacro = ClassType.make("kawa.lang.Macro");
31 static PrimProcedure makeHygienic
32 = new PrimProcedure(typeMacro.getDeclaredMethod("make", 3));
33 static PrimProcedure makeNonHygienic
34 = new PrimProcedure(typeMacro.getDeclaredMethod("makeNonHygienic", 3));
35 static PrimProcedure setCapturedScope
36 = new PrimProcedure(typeMacro.getDeclaredMethod("setCapturedScope", 1));
37
38 boolean hygienic;
39
40 public Expression rewriteForm (Pair form, Translator tr)
41 {
42 return tr.syntaxError("define-syntax not in a body");
43 }
44
45 public void scanForm (Pair st, ScopeExp defs, Translator tr)
46 {
47 SyntaxForm syntax = null;
48 Object st_cdr = st.cdr;
49 while (st_cdr instanceof SyntaxForm)
50 {
51 syntax = (SyntaxForm) st_cdr;
52 st_cdr = syntax.form;
53 }
54 Object p = st_cdr;
55 Object name;
56 if (p instanceof Pair)
57 {
58 Pair pp = (Pair) p;
59 name = pp.car;
60 p = pp.cdr;
61 }
62 else
63 name = null;
64 SyntaxForm nameSyntax = syntax;
65 while (name instanceof SyntaxForm)
66 {
67 nameSyntax = (SyntaxForm) name;
68 name = nameSyntax.form;
69 }
70 name = tr.namespaceResolve(name);
71 if (! (name instanceof String || name instanceof Symbol))
72 {
73 tr.formStack.addElement(tr.syntaxError("missing macro name for "+Translator.safeCar(st)));
74 return;
75 }
76 if (p == null || Translator.safeCdr(p) != LList.Empty)
77 {
78 tr.formStack.addElement(tr.syntaxError("invalid syntax for "+getName()));
79 return;
80 }
81
82 Declaration decl = tr.define(name, nameSyntax, defs);
83 decl.setType(typeMacro);
84 tr.push(decl);
85
86 Macro savedMacro = tr.currentMacroDefinition;
87 Macro macro = Macro.make(decl);
88 macro.setHygienic(hygienic);
89 tr.currentMacroDefinition = macro;
90 Expression rule = tr.rewrite_car((Pair) p, syntax);
91 tr.currentMacroDefinition = savedMacro;
92 macro.expander = rule;
93
94 if (rule instanceof LambdaExp)
95 ((LambdaExp) rule).setFlag(LambdaExp.NO_FIELD);
96 Expression args[] = new Expression[3];
97 args[0] = new QuoteExp(name);
98 args[1] = rule;
99 args[2] = ThisExp.makeGivingContext(defs);
100 rule = new ApplyExp(hygienic ? makeHygienic : makeNonHygienic,
101 args);
102 decl.noteValue(rule);
103 decl.setProcedureDecl(true);
104
105 if (decl.context instanceof ModuleExp)
106 {
107 SetExp result = new SetExp (decl, rule);
108 result.setDefining (true);
109 if (tr.getLanguage().hasSeparateFunctionNamespace())
110 result.setFuncDef(true);
111
112 tr.formStack.addElement(result);
113
114 if (tr.immediate)
115 {
116 args = new Expression[2];
117 args[0] = new ReferenceExp(decl);
118 args[1] = new QuoteExp(defs);
119 tr.formStack.addElement(new ApplyExp(setCapturedScope, args));
120 }
121 }
122 }
123 }
124 |
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