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1 package jfun.yan.xml.nuts.optional;
2
3 import java.lang.reflect.Array  ;
4 import java.util.Collection ;
5 import java.util.Iterator ;
6
7 import jfun.yan.Binder;
8 import jfun.yan.Components;
9 import jfun.yan.Creator;
10 import jfun.yan.Monad;
11 import jfun.yan.xml.nuts.DelegatingBinderNut;
12
13
24 public class ForeachNut extends DelegatingBinderNut {
25 public Binder eval() throws Exception {
26 final Binder binder = getMandatory();
27 return new Binder(){
28 public Creator bind(Object v)
29 throws Throwable {
30 if(v==null) return Components.value(null);
31 final Creator[] steps = getNextSteps(v, binder);
32 return Monad.sequence(steps);
33 }
34 public String toString(){
35 return "foreach";
36 }
37 };
38 }
39 private static Creator[] getNextSteps(Object obj, Binder next)
40 throws Throwable {
41 if(obj instanceof java.util.Map ){
42 return getNextSteps((java.util.Map )obj, next);
43 }
44 else if(obj instanceof Object []){
45 return getNextSteps((Object [])obj, next);
46 }
47 else if(obj instanceof Collection ){
48 return getNextSteps((Collection )obj, next);
49 }
50 else if(obj.getClass().isArray()){
51 return getNextStepsForArray(obj, next);
52 }
53 else{
54 return new Creator[]{next.bind(obj)};
55 }
56 }
57 private static Creator[] getNextStepsForArray(Object arr, Binder next)
58 throws Throwable {
59 final int sz = Array.getLength(arr);
60 final Creator[] result = new Creator[sz];
61 for(int i=0; i<sz ;i++){
62 result[i] = next.bind(Array.get(arr, i));
63 }
64 return result;
65 }
66
67 private static Creator[] getNextSteps(Object [] arr, Binder next)
68 throws Throwable {
69 final Creator[] result = new Creator[arr.length];
70 for(int i=0; i<arr.length ;i++){
71 result[i] = next.bind(arr[i]);
72 }
73 return result;
74 }
75 private static Creator[] getNextSteps(java.util.Map m, Binder next)
76 throws Throwable {
77 return getNextSteps(m.values(), next);
78 }
79 private static Creator[] getNextSteps(Collection c, Binder next)
80 throws Throwable {
81 final Creator[] result = new Creator[c.size()];
82 int i=0;
83 for(Iterator it = c.iterator(); it.hasNext();i++){
84 result[i] = next.bind(it.next());
85 }
86 return result;
87 }
88 }
89 |
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Java API By Example, From Geeks To Geeks.