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1 package gnu.commonlisp.lang;
2 import gnu.mapping.*;
3 import gnu.lists.*;
4
5
7
8 public class Symbols
9 {
10 private Symbols ()
11 {
12 }
13
14 public static boolean isSymbol(Object  val)
15 {
16 return val instanceof String || val == Lisp2.FALSE
17 || val instanceof Symbol;
18 }
19
20 public static boolean isBound(Object sym)
21 {
22 if (sym == Lisp2.FALSE)
23 return true;
24 Environment env = Environment.getCurrent();
25 Symbol symbol;
26 if (sym instanceof Symbol)
27 symbol = (Symbol) sym;
28 else
29 symbol = env.defaultNamespace().lookup((String ) sym);
30 return symbol != null && env.isBound(symbol);
31 }
32
33 public static Symbol getSymbol(Environment env, Object sym)
34 {
35 if (sym == Lisp2.FALSE)
36 sym = "nil";
37 return sym instanceof Symbol ? (Symbol) sym
38 : env.defaultNamespace().getSymbol((String ) sym);
39 }
40
41 public static Symbol getSymbol(Object sym)
42 {
43 if (sym == Lisp2.FALSE)
44 sym = "nil";
45 return sym instanceof Symbol ? (Symbol) sym
46 : Namespace.getDefaultSymbol((String ) sym); }
48
49 public static Object getPrintName(Object sym)
50 {
51 return sym == Lisp2.FALSE ? "nil"
52 : Lisp2.getString(((Symbol) sym).getName());
53 }
54
55 public static Object getFunctionBinding (Object symbol)
56 {
57 return Environment.getCurrent().getFunction(getSymbol(symbol));
58 }
59
60 public static Object getFunctionBinding (Environment environ, Object symbol)
61 {
62 return environ.getFunction(getSymbol(symbol));
63 }
64
65 public static void setFunctionBinding (Environment environ,
66 Object symbol, Object newValue)
67 {
68 environ.put(getSymbol(symbol), EnvironmentKey.FUNCTION, newValue);
69 }
70
71 }
72 |
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