Mercurial > hg > expressionparser

annotate expr.py @ 0:ae57e69e4b15

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
simple expression parser
author Ted Mielczarek <ted.mielczarek@gmail.com>
date Wed, 01 Jun 2011 19:58:56 -0400
parents
children c45135ec8c13
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
0
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
1 #!/usr/bin/env python
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
2
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
3 import re, unittest
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
4
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
5 # ideas taken from http://effbot.org/zone/simple-top-down-parsing.htm
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
6 # token classes
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
7 class ident_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
8 def __init__(self, value):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
9 self.value = value
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
10 def nud(self, parser):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
11 # identifiers take their value from the value mappings passed
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
12 # to the parser
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
13 return parser.value(self.value)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
14
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
15 class int_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
16 def __init__(self, value):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
17 self.value = int(value)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
18 def nud(self, parser):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
19 return self.value
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
20
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
21 class bool_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
22 def __init__(self, value):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
23 self.value = {'true':True, 'false':False}[value]
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
24 def nud(self, parser):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
25 return self.value
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
26
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
27 class eq_op_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
28 "=="
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
29 lbp = 20
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
30 def led(self, parser, left):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
31 return left == parser.expression(self.lbp)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
32
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
33 class neq_op_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
34 "!="
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
35 lbp = 20
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
36 def led(self, parser, left):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
37 return left != parser.expression(self.lbp)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
38
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
39 class and_op_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
40 "&&"
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
41 lbp = 11
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
42 def led(self, parser, left):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
43 right = parser.expression(self.lbp)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
44 return left and right
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
45
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
46 class or_op_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
47 "||"
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
48 lbp = 10
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
49 def led(self, parser, left):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
50 right = parser.expression(self.lbp)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
51 return left or right
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
52
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
53 class lparen_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
54 "("
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
55 lbp = 50
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
56 def nud(self, parser):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
57 expr = parser.expression()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
58 parser.advance(rparen_token)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
59 return expr
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
60
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
61 class rparen_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
62 ")"
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
63 lbp = 0
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
64
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
65 class string_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
66 def __init__(self, value):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
67 self.value = value
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
68 def nud(self, parser):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
69 return self.value
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
70
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
71 class end_token:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
72 # lowest left binding power, always ends parsing
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
73 lbp = 0
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
74
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
75 class ExpressionParser(object):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
76 def __init__(self, text, valuemapping):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
77 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
78 Initialize the parser with input |text|, and |valuemapping| as
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
79 a dict mapping identifier names to values.
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
80 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
81 self.text = text
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
82 self.valuemapping = valuemapping
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
83
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
84 def _tokenize(self):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
85 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
86 Lex the input text into tokens and yield them in sequence.
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
87 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
88 # scanner callbacks
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
89 def bool_(scanner, t): return bool_token(t)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
90 def identifier(scanner, t): return ident_token(t)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
91 def integer(scanner, t): return int_token(t)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
92 def eq(scanner, t): return eq_op_token()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
93 def neq(scanner, t): return neq_op_token()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
94 def or_(scanner, t): return or_op_token()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
95 def and_(scanner, t): return and_op_token()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
96 def lparen(scanner, t): return lparen_token()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
97 def rparen(scanner, t): return rparen_token()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
98 def string_(scanner, t): return string_token(t[1:-1])
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
99
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
100 scanner = re.Scanner([
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
101 (r"true|false", bool_),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
102 (r"[a-zA-Z_]\w*", identifier),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
103 (r"[0-9]+", integer),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
104 (r'"[^"]*"', string_),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
105 (r"==", eq),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
106 (r"!=", neq),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
107 (r"\|\|", or_),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
108 (r"&&", and_),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
109 (r"\(", lparen),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
110 (r"\)", rparen),
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
111 (r"\s+", None), # skip whitespace
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
112 ])
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
113 tokens, remainder = scanner.scan(self.text)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
114 for t in tokens:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
115 yield t
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
116 yield end_token()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
117
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
118 def value(self, ident):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
119 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
120 Look up the value of |ident| in the value mapping passed in the
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
121 constructor.
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
122 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
123 return self.valuemapping[ident]
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
124
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
125 def advance(self, expected):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
126 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
127 Assert that the next token is an instance of |expected|, and advance
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
128 to the next token.
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
129 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
130 if not isinstance(self.token, expected):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
131 raise Exception, "Unexpected token!"
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
132 self.token = self.iter.next()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
133
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
134 def expression(self, rbp=0):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
135 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
136 Parse and return the value of an expression until a token with
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
137 right binding power greater than rbp is encountered.
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
138 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
139 t = self.token
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
140 self.token = self.iter.next()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
141 left = t.nud(self)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
142 while rbp < self.token.lbp:
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
143 t = self.token
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
144 self.token = self.iter.next()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
145 left = t.led(self, left)
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
146 return left
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
147
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
148 def parse(self):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
149 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
150 Parse and return the value of the expression in the text
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
151 passed to the constructor.
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
152 """
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
153 self.iter = self._tokenize()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
154 self.token = self.iter.next()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
155 return self.expression()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
156
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
157 class ExpressionParserUnittest(unittest.TestCase):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
158 def parse(self, text, values):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
159 return ExpressionParser(text, values).parse()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
160
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
161 def test_BasicValues(self):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
162 self.assertEqual(1, self.parse("1", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
163 self.assertEqual(100, self.parse("100", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
164 self.assertEqual(True, self.parse("true", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
165 self.assertEqual(False, self.parse("false", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
166 self.assertEqual("", self.parse('""', {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
167 self.assertEqual("foo bar", self.parse('"foo bar"', {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
168 self.assertEqual(1, self.parse("foo", {'foo':1}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
169 self.assertEqual(True, self.parse("bar", {'bar':True}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
170 self.assertEqual("xyz", self.parse("abc123", {'abc123':"xyz"}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
171
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
172 def test_Equality(self):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
173 self.assertTrue(self.parse("true == true", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
174 self.assertTrue(self.parse("false == false", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
175 self.assertTrue(self.parse("false == false", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
176 self.assertTrue(self.parse("1 == 1", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
177 self.assertTrue(self.parse("100 == 100", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
178 self.assertTrue(self.parse('"some text" == "some text"', {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
179 self.assertTrue(self.parse("true != false", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
180 self.assertTrue(self.parse("1 != 2", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
181 self.assertTrue(self.parse('"text" != "other text"', {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
182 self.assertTrue(self.parse("foo == true", {'foo': True}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
183 self.assertTrue(self.parse("foo == 1", {'foo': 1}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
184 self.assertTrue(self.parse('foo == "bar"', {'foo': 'bar'}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
185 self.assertTrue(self.parse("foo == bar", {'foo': True, 'bar': True}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
186 self.assertTrue(self.parse("true == foo", {'foo': True}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
187 self.assertTrue(self.parse("foo != true", {'foo': False}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
188 self.assertTrue(self.parse("foo != 2", {'foo': 1}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
189 self.assertTrue(self.parse('foo != "bar"', {'foo': 'abc'}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
190 self.assertTrue(self.parse("foo != bar", {'foo': True, 'bar': False}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
191 self.assertTrue(self.parse("true != foo", {'foo': False}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
192
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
193 def test_Conjunctions(self):
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
194 self.assertTrue(self.parse("true && true", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
195 self.assertTrue(self.parse("true || false", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
196 self.assertFalse(self.parse("false || false", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
197 self.assertFalse(self.parse("true && false", {}))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
198
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
199 if __name__ == '__main__':
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
200
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
201
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
202
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
203
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
204 unittest.main()
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
205
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
206 #parser = ExpressionParser(sys.argv[1], dict((a,int(b)) for a,b in (x.split('=') for x in sys.argv[2:])))
ae57e69e4b15 simple expression parser
Ted Mielczarek <ted.mielczarek@gmail.com>
parents:
diff changeset
207 #print "%s: %s" % (sys.argv[1],parser.parse())