1 // Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
4 // FIXME: should allow parentScope to be a JS, not a JSScope
5 // FIXME: Index local vars by number and lookup in an array
6 /** Implementation of a JavaScript Scope */
7 public class JSScope extends JS {
9 private JSScope parentScope;
11 private static final Object NULL_PLACEHOLDER = new Object();
13 public JSScope(JSScope parentScope) { this.parentScope = parentScope; }
14 public void declare(String s) throws JSExn { super.put(s, NULL_PLACEHOLDER); }
15 public JSScope getParentScope() { return parentScope; }
17 public Object get(Object key) throws JSExn {
18 Object o = super.get(key);
19 if (o != null) return o == NULL_PLACEHOLDER ? null : o;
20 else return parentScope == null ? null : parentScope.get(key);
23 public boolean has(Object key) throws JSExn { return super.get(key) != null; }
24 public void put(Object key, Object val) throws JSExn {
25 if (parentScope != null && !has(key)) parentScope.put(key, val);
26 else super.put(key, val == null ? NULL_PLACEHOLDER : val);
29 public JSScope top() {
31 while(s.parentScope != null) s = s.parentScope;
35 public static class Global extends JSScope {
36 private final static Double NaN = new Double(Double.NaN);
37 private final static Double POSITIVE_INFINITY = new Double(Double.POSITIVE_INFINITY);
39 public Global() { super(null); }
40 public Object get(Object key) throws JSExn {
42 case "NaN": return NaN;
43 case "Infinity": return POSITIVE_INFINITY;
44 case "undefined": return null;
45 case "stringFromCharCode": return METHOD;
46 case "parseInt": return METHOD;
47 case "parseFloat": return METHOD;
48 case "isNaN": return METHOD;
49 case "isFinite": return METHOD;
50 case "decodeURI": return METHOD;
51 case "decodeURIComponent": return METHOD;
52 case "encodeURI": return METHOD;
53 case "encodeURIComponent": return METHOD;
54 case "escape": return METHOD;
55 case "unescape": return METHOD;
57 return super.get(key);
60 public Object callMethod(Object method, Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
64 case "stringFromCharCode":
65 char buf[] = new char[nargs];
66 for(int i=0; i<nargs; i++) buf[i] = (char)(JS.toInt(i==0?a0:i==1?a1:i==2?a2:rest[i-3]) & 0xffff);
67 return new String(buf);
73 case "parseInt": return parseInt(a0, N(0));
74 case "parseFloat": return parseFloat(a0);
75 case "isNaN": { double d = toDouble(a0); return d == d ? F : T; }
76 case "isFinite": { double d = toDouble(a0); return (d == d && !Double.isInfinite(d)) ? T : F; }
77 case "decodeURI": throw new JSExn("unimplemented");
78 case "decodeURIComponent": throw new JSExn("unimplemented");
79 case "encodeURI": throw new JSExn("unimplemented");
80 case "encodeURIComponent": throw new JSExn("unimplemented");
81 case "escape": throw new JSExn("unimplemented");
82 case "unescape": throw new JSExn("unimplemented");
88 case "parseInt": return parseInt(a0, a1);
93 return super.callMethod(method, a0, a1, a2, rest, nargs);
96 private Object parseInt(Object arg, Object r) throws JSExn {
97 int radix = JS.toInt(r);
98 String s = JS.toString(arg);
100 int length = s.length();
103 if(radix != 0 && (radix < 2 || radix > 36)) return NaN;
104 while(start < length && Character.isWhitespace(s.charAt(start))) start++;
105 if((length >= start+1) && (s.charAt(start) == '+' || s.charAt(start) == '-')) {
106 sign = s.charAt(start) == '+' ? 1 : -1;
109 if(radix == 0 && length >= start+1 && s.charAt(start) == '0') {
111 if(length >= start+1 && (s.charAt(start) == 'x' || s.charAt(start) == 'X')) {
116 if(length == start || Character.digit(s.charAt(start+1),8)==-1) return JS.ZERO;
119 if(radix == 0) radix = 10;
120 if(length == start || Character.digit(s.charAt(start),radix) == -1) return NaN;
121 // try the fast way first
123 String s2 = start == 0 ? s : s.substring(start);
124 return JS.N(sign*Integer.parseInt(s2,radix));
125 } catch(NumberFormatException e) { }
126 // fall through to a slower but emca-compliant method
127 for(int i=start;i<length;i++) {
128 int digit = Character.digit(s.charAt(i),radix);
131 if(n < 0) return NaN; // overflow;
133 if(n <= Integer.MAX_VALUE) return JS.N(sign*(int)n);
134 return JS.N((long)sign*n);
137 private Object parseFloat(Object arg) throws JSExn {
138 String s = JS.toString(arg);
140 int length = s.length();
141 while(start < length && Character.isWhitespace(s.charAt(0))) start++;
143 // as long as the string has no trailing garbage,this is fast, its slow with
147 return JS.N(s.substring(start,length));
148 } catch(NumberFormatException e) { }