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1
6 package com.hp.hpl.jena.graph.query;
7
8
12 public class Rewrite
13 {
14 public static Expression rewriteStringMatch( Expression e )
15 {
16 Expression L = e.getArg(0), R = e.getArg(1);
17 PatternLiteral pattern = Rewrite.getPattern( R );
18 if (pattern == null)
19 return e;
20 else if (isStartsWith( pattern ))
21 return startsWith( L, pattern.getPatternString().substring(1), pattern.getPatternModifiers() );
22 else if (isContains( pattern ))
23 return contains( L, pattern.getPatternString(), pattern.getPatternModifiers() );
24 else if (isEndsWith( pattern ))
25 return endsWith( L, front( pattern.getPatternString() ), pattern.getPatternModifiers() );
26 return e;
27 }
28
29 protected static String  front( String s )
30 { return s.substring( 0, s.length() - 1 ); }
31
32 public static PatternLiteral getPattern( Expression E )
33 {
34 if (E instanceof PatternLiteral)
35 {
36 PatternLiteral L = (PatternLiteral) E;
37 if (L.getPatternLanguage().equals( PatternLiteral.rdql )) return L;
38 }
39 return null;
40 }
41
42
52 public static abstract class DyadicLiteral extends Dyadic
53 {
54 public DyadicLiteral( Expression L, String F, String R )
55 { super( L, F, new Expression.Fixed( R ) ); }
56
57 public boolean evalBool( Object l, Object r )
58 { return evalBool( l.toString(), r.toString() ); }
59
60 protected abstract boolean evalBool( String l, String r );
61 }
62
63 public static abstract class DyadicLower extends DyadicLiteral
64 {
65 public DyadicLower( Expression L, String F, String R )
66 { super( L, F, R.toLowerCase() ); }
67 }
68
69 public static Expression endsWith( Expression L, String content, String modifiers )
70 {
71 if (modifiers.equals( "i" ))
72 {
73 return new DyadicLower( L, ExpressionFunctionURIs.J_endsWithInsensitive, content )
74 {
75 public boolean evalBool( String l, String r )
76 { return l.toLowerCase().endsWith( r ); }
77 };
78 }
79 else
80 {
81 return new DyadicLiteral( L, ExpressionFunctionURIs.J_EndsWith, content )
82 {
83 public boolean evalBool( String l, String r )
84 { return l.endsWith( r ); }
85 };
86 }
87 }
88
89 public static Expression startsWith( Expression L, String content, String modifiers )
90 {
91 if (modifiers.equals( "i" ))
92 {
93 return new DyadicLower( L, ExpressionFunctionURIs.J_startsWithInsensitive, content )
94 {
95 public boolean evalBool( String l, String r )
96 { return l.toLowerCase().startsWith( r ); }
97 };
98 }
99 else
100 {
101 return new DyadicLiteral( L, ExpressionFunctionURIs.J_startsWith, content )
102 {
103 public boolean evalBool( String l, String r )
104 { return l.startsWith( r ); }
105 };
106 }
107 }
108
109 public static Expression contains( Expression L, String content, String modifiers )
110 {
111 if (modifiers.equals( "i" ))
112 {
113 return new DyadicLower( L, ExpressionFunctionURIs.J_containsInsensitive, content )
114 {
115 public boolean evalBool( String l, String r )
116 { return l.toLowerCase().indexOf( r ) > -1; }
117 };
118 }
119 else
120 {
121 return new DyadicLiteral( L, ExpressionFunctionURIs.J_contains, content )
122 {
123 public boolean evalBool( String l, String r )
124 { return l.indexOf( r ) > -1; }
125 };
126 }
127 }
128
129 public static boolean notSpecial( String pattern )
130 { return pattern.matches( "[A-Za-z0-9-_:/ ]*" ); }
131
132 public static boolean isContains( PatternLiteral pattern )
133 { return notSpecial( pattern.getPatternString() ) && iOnly( pattern.getPatternModifiers() ); }
134
135 protected static boolean iOnly( String modifiers )
136 { return modifiers.equals( "" ) || modifiers.equals( "i" ); }
137
138 public static boolean isStartsWith( PatternLiteral pattern )
139 {
140 String s = pattern.getPatternString();
141 return s.startsWith( "^" ) && notSpecial( s.substring( 1 ) );
142 }
143
144 public static boolean isEndsWith( PatternLiteral pattern )
145 {
146 String s = pattern.getPatternString();
147 return s.endsWith( "$" ) && notSpecial( s.substring( 0, s.length() - 1 ) );
148 }
149
150 }
151
152
153 |
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