在《使用Antlr实现表达式引擎 》中写了主要的类，实现表达式的语法定义文件如下（使用的Antlr为3.0发布版本）：
1
grammar XExpression;
2
3options {
4 language=CSharp;
5 superClass=XExpressionBaseParser;
6}
7
8@header {
9using XSoft.XExpression;
10}
11
12@members {
13 public XExpressionParser()
14 : base(null)
15 {
16 }
17
18 public override void Compile()
19 {
20 TokenStream = new CommonTokenStream(new XExpressionLexer(new ANTLRStringStream(Expression)));
21 ResultNode = xExpression();
22 }
23}
24
25xExpression returns[ExprNode value]
26 : a= logicalOrExpression {$value=a;};
27
28logicalOrExpression returns[ExprNode value]
29 : a=logicalAndExpression {$value=a;}
30 (f=OR b=logicalAndExpression {GetNestedResultNode(ref $value, f, b);} )* ;
31
32logicalAndExpression returns[ExprNode value]
33 : a=relationalExpression {$value=a;}
34 (f=AND b=relationalExpression {GetNestedResultNode(ref $value, f, b);} )* ;
35
36relationalExpression returns[ExprNode value]
37 : a=additiveExpression {$value=a;}
38 ((f=EQUAL | f=NOT_EQUAL | f=LESS_THAN | f=LESS_THAN_OR_EQUAL | f=GREATER_THAN | f=GREATER_THAN_OR_EQUAL) b=additiveExpression {GetNestedResultNode(ref $value, f, b);} )?
39 ;
40
41additiveExpression returns[ExprNode value]
42 : a=multiplyExpression {$value=a;}
43 ((f=PLUS|f=MINUS) b=multiplyExpression {GetNestedResultNode(ref $value, f, b);} )*
44 ;
45
46
47multiplyExpression returns[ExprNode value]
48 : a=powExpr {$value=a;}
49 ((f=STAR| f=DIV | f=MOD) b=powExpr {GetNestedResultNode(ref $value, f, b);} )* ;
50
51powExpr returns[ExprNode value]
52 : a=unaryExpression {$value=a;}
53 (f=POWER b=unaryExpression {GetNestedResultNode(ref $value, f, b);} )? ;
54
55unaryExpression returns[ExprNode value]
56 : (f=PLUS | f=MINUS | f=NOT) b=unaryExpression {GetNestedResultNodeArgsNotIncludeValue(ref $value, f, b);}
57 | a=primaryExpression {$value=a;}
58 ;
59
60primaryExpression returns[ExprNode value]
61 : (a=parenExpr|a=literal | a=function) {$value=a;};
62
63parenExpr returns[ExprNode value]
64 : LPAREN a=xExpression RPAREN {$value=a;};
65
66literal returns[ExprNode value]
67 : (a=numbericLiteral| a= stringLiteral | a=datetimeLiteral) {$value=a;};
68
69function returns[ExprNode value]
70@init { ArrayList list_arg = new ArrayList(); }
71 : f=IDENTIFIER LPAREN (arg=argument {list_arg.Add(arg);} (COMMA arg=argument { list_arg.Add(arg); } )*)? RPAREN
72 { $value = GetNestedResultNode(f, list_arg); }
73 ;
74
75argument returns[ExprNode value]
76 : a=xExpression {$value=a;};
77
78numbericLiteral returns[ExprNode value]
79 : a=INTEGER_LITERAL {$value = new ConstNode(new IntegerExprData(Convert.ToInt32(a.Text)));}
80 | a=DECIMAL_LITERAL {$value = new ConstNode(new DecimalExprData(Convert.ToDecimal(Convert.ToDouble(a.Text)))); }
81 ;
82
83datetimeLiteral returns[ExprNode value]
84 : a=DATETIME_LITERAL
85 {$value = new ConstNode(new DateTimeExprData(DateTime.Parse(a.Text.Substring(1, a.Text.Length - 2))));}
86
87 ;
88
89stringLiteral returns[ExprNode value]
90 : a=STRING_LITERAL
91 {$value = new ConstNode(new StringExprData(a.Text.Substring(1, a.Text.Length - 2)));}
92 ;
93
94AND: 'and';
95OR: 'or';
96
97NOT: 'not';
98
99COMMA : ',' ;
100
101PLUS: '+' ;
102MINUS: '-' ;
103DIV: '/' ;
104STAR: '*' ;
105MOD: '%' ;
106POWER: '^' ;
107
108EQUAL: '=';
109NOT_EQUAL: '<>' ;
110LESS_THAN: '<' ;
111LESS_THAN_OR_EQUAL: '<=' ;
112GREATER_THAN: '>' ;
113GREATER_THAN_OR_EQUAL: '>=' ;
114
115LPAREN: '(';
116RPAREN: ')';
117
118DATETIME_LITERAL: '\'' Digit Digit Digit Digit '-' Digit (Digit)? '-' Digit (Digit)? '\'';
119
120STRING_LITERAL : '"'(~'"')* '"' ;
121
122IDENTIFIER: LETTER (LETTER|Digit)* ;
123
124fragment
125LETTER : 'A'..'Z'|'a'..'z'|'_';
126
127DECIMAL_LITERAL: (INTEGER_LITERAL)? '.' Digit* Exponent? ;
128fragment
129Exponent : ('e'|'E') INTEGER_LITERAL;
130
131INTEGER_LITERAL : Digit+ ;
132
133fragment
134Digit :'0'..'9';
135
136fragment
137SIGN : '+' | '-';
138
139WS : (' '|'\t')+ { $channel=HIDDEN; } ;
140
posted on 2007-06-28 22:32
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