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920dae64 AT |
1 | """Tokenization help for Python programs. |
2 | ||
3 | generate_tokens(readline) is a generator that breaks a stream of | |
4 | text into Python tokens. It accepts a readline-like method which is called | |
5 | repeatedly to get the next line of input (or "" for EOF). It generates | |
6 | 5-tuples with these members: | |
7 | ||
8 | the token type (see token.py) | |
9 | the token (a string) | |
10 | the starting (row, column) indices of the token (a 2-tuple of ints) | |
11 | the ending (row, column) indices of the token (a 2-tuple of ints) | |
12 | the original line (string) | |
13 | ||
14 | It is designed to match the working of the Python tokenizer exactly, except | |
15 | that it produces COMMENT tokens for comments and gives type OP for all | |
16 | operators | |
17 | ||
18 | Older entry points | |
19 | tokenize_loop(readline, tokeneater) | |
20 | tokenize(readline, tokeneater=printtoken) | |
21 | are the same, except instead of generating tokens, tokeneater is a callback | |
22 | function to which the 5 fields described above are passed as 5 arguments, | |
23 | each time a new token is found.""" | |
24 | ||
25 | __author__ = 'Ka-Ping Yee <ping@lfw.org>' | |
26 | __credits__ = \ | |
27 | 'GvR, ESR, Tim Peters, Thomas Wouters, Fred Drake, Skip Montanaro' | |
28 | ||
29 | import string, re | |
30 | from token import * | |
31 | ||
32 | import token | |
33 | __all__ = [x for x in dir(token) if x[0] != '_'] + ["COMMENT", "tokenize", | |
34 | "generate_tokens", "NL"] | |
35 | del x | |
36 | del token | |
37 | ||
38 | COMMENT = N_TOKENS | |
39 | tok_name[COMMENT] = 'COMMENT' | |
40 | NL = N_TOKENS + 1 | |
41 | tok_name[NL] = 'NL' | |
42 | N_TOKENS += 2 | |
43 | ||
44 | def group(*choices): return '(' + '|'.join(choices) + ')' | |
45 | def any(*choices): return group(*choices) + '*' | |
46 | def maybe(*choices): return group(*choices) + '?' | |
47 | ||
48 | Whitespace = r'[ \f\t]*' | |
49 | Comment = r'#[^\r\n]*' | |
50 | Ignore = Whitespace + any(r'\\\r?\n' + Whitespace) + maybe(Comment) | |
51 | Name = r'[a-zA-Z_]\w*' | |
52 | ||
53 | Hexnumber = r'0[xX][\da-fA-F]*[lL]?' | |
54 | Octnumber = r'0[0-7]*[lL]?' | |
55 | Decnumber = r'[1-9]\d*[lL]?' | |
56 | Intnumber = group(Hexnumber, Octnumber, Decnumber) | |
57 | Exponent = r'[eE][-+]?\d+' | |
58 | Pointfloat = group(r'\d+\.\d*', r'\.\d+') + maybe(Exponent) | |
59 | Expfloat = r'\d+' + Exponent | |
60 | Floatnumber = group(Pointfloat, Expfloat) | |
61 | Imagnumber = group(r'\d+[jJ]', Floatnumber + r'[jJ]') | |
62 | Number = group(Imagnumber, Floatnumber, Intnumber) | |
63 | ||
64 | # Tail end of ' string. | |
65 | Single = r"[^'\\]*(?:\\.[^'\\]*)*'" | |
66 | # Tail end of " string. | |
67 | Double = r'[^"\\]*(?:\\.[^"\\]*)*"' | |
68 | # Tail end of ''' string. | |
69 | Single3 = r"[^'\\]*(?:(?:\\.|'(?!''))[^'\\]*)*'''" | |
70 | # Tail end of """ string. | |
71 | Double3 = r'[^"\\]*(?:(?:\\.|"(?!""))[^"\\]*)*"""' | |
72 | Triple = group("[uU]?[rR]?'''", '[uU]?[rR]?"""') | |
73 | # Single-line ' or " string. | |
74 | String = group(r"[uU]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*'", | |
75 | r'[uU]?[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*"') | |
76 | ||
77 | # Because of leftmost-then-longest match semantics, be sure to put the | |
78 | # longest operators first (e.g., if = came before ==, == would get | |
79 | # recognized as two instances of =). | |
80 | Operator = group(r"\*\*=?", r">>=?", r"<<=?", r"<>", r"!=", | |
81 | r"//=?", | |
82 | r"[+\-*/%&|^=<>]=?", | |
83 | r"~") | |
84 | ||
85 | Bracket = '[][(){}]' | |
86 | Special = group(r'\r?\n', r'[:;.,`@]') | |
87 | Funny = group(Operator, Bracket, Special) | |
88 | ||
89 | PlainToken = group(Number, Funny, String, Name) | |
90 | Token = Ignore + PlainToken | |
91 | ||
92 | # First (or only) line of ' or " string. | |
93 | ContStr = group(r"[uU]?[rR]?'[^\n'\\]*(?:\\.[^\n'\\]*)*" + | |
94 | group("'", r'\\\r?\n'), | |
95 | r'[uU]?[rR]?"[^\n"\\]*(?:\\.[^\n"\\]*)*' + | |
96 | group('"', r'\\\r?\n')) | |
97 | PseudoExtras = group(r'\\\r?\n', Comment, Triple) | |
98 | PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name) | |
99 | ||
100 | tokenprog, pseudoprog, single3prog, double3prog = map( | |
101 | re.compile, (Token, PseudoToken, Single3, Double3)) | |
102 | endprogs = {"'": re.compile(Single), '"': re.compile(Double), | |
103 | "'''": single3prog, '"""': double3prog, | |
104 | "r'''": single3prog, 'r"""': double3prog, | |
105 | "u'''": single3prog, 'u"""': double3prog, | |
106 | "ur'''": single3prog, 'ur"""': double3prog, | |
107 | "R'''": single3prog, 'R"""': double3prog, | |
108 | "U'''": single3prog, 'U"""': double3prog, | |
109 | "uR'''": single3prog, 'uR"""': double3prog, | |
110 | "Ur'''": single3prog, 'Ur"""': double3prog, | |
111 | "UR'''": single3prog, 'UR"""': double3prog, | |
112 | 'r': None, 'R': None, 'u': None, 'U': None} | |
113 | ||
114 | triple_quoted = {} | |
115 | for t in ("'''", '"""', | |
116 | "r'''", 'r"""', "R'''", 'R"""', | |
117 | "u'''", 'u"""', "U'''", 'U"""', | |
118 | "ur'''", 'ur"""', "Ur'''", 'Ur"""', | |
119 | "uR'''", 'uR"""', "UR'''", 'UR"""'): | |
120 | triple_quoted[t] = t | |
121 | single_quoted = {} | |
122 | for t in ("'", '"', | |
123 | "r'", 'r"', "R'", 'R"', | |
124 | "u'", 'u"', "U'", 'U"', | |
125 | "ur'", 'ur"', "Ur'", 'Ur"', | |
126 | "uR'", 'uR"', "UR'", 'UR"' ): | |
127 | single_quoted[t] = t | |
128 | ||
129 | tabsize = 8 | |
130 | ||
131 | class TokenError(Exception): pass | |
132 | ||
133 | class StopTokenizing(Exception): pass | |
134 | ||
135 | def printtoken(type, token, (srow, scol), (erow, ecol), line): # for testing | |
136 | print "%d,%d-%d,%d:\t%s\t%s" % \ | |
137 | (srow, scol, erow, ecol, tok_name[type], repr(token)) | |
138 | ||
139 | def tokenize(readline, tokeneater=printtoken): | |
140 | """ | |
141 | The tokenize() function accepts two parameters: one representing the | |
142 | input stream, and one providing an output mechanism for tokenize(). | |
143 | ||
144 | The first parameter, readline, must be a callable object which provides | |
145 | the same interface as the readline() method of built-in file objects. | |
146 | Each call to the function should return one line of input as a string. | |
147 | ||
148 | The second parameter, tokeneater, must also be a callable object. It is | |
149 | called once for each token, with five arguments, corresponding to the | |
150 | tuples generated by generate_tokens(). | |
151 | """ | |
152 | try: | |
153 | tokenize_loop(readline, tokeneater) | |
154 | except StopTokenizing: | |
155 | pass | |
156 | ||
157 | # backwards compatible interface | |
158 | def tokenize_loop(readline, tokeneater): | |
159 | for token_info in generate_tokens(readline): | |
160 | tokeneater(*token_info) | |
161 | ||
162 | def generate_tokens(readline): | |
163 | """ | |
164 | The generate_tokens() generator requires one argment, readline, which | |
165 | must be a callable object which provides the same interface as the | |
166 | readline() method of built-in file objects. Each call to the function | |
167 | should return one line of input as a string. | |
168 | ||
169 | The generator produces 5-tuples with these members: the token type; the | |
170 | token string; a 2-tuple (srow, scol) of ints specifying the row and | |
171 | column where the token begins in the source; a 2-tuple (erow, ecol) of | |
172 | ints specifying the row and column where the token ends in the source; | |
173 | and the line on which the token was found. The line passed is the | |
174 | logical line; continuation lines are included. | |
175 | """ | |
176 | lnum = parenlev = continued = 0 | |
177 | namechars, numchars = string.ascii_letters + '_', '0123456789' | |
178 | contstr, needcont = '', 0 | |
179 | contline = None | |
180 | indents = [0] | |
181 | ||
182 | while 1: # loop over lines in stream | |
183 | line = readline() | |
184 | lnum = lnum + 1 | |
185 | pos, max = 0, len(line) | |
186 | ||
187 | if contstr: # continued string | |
188 | if not line: | |
189 | raise TokenError, ("EOF in multi-line string", strstart) | |
190 | endmatch = endprog.match(line) | |
191 | if endmatch: | |
192 | pos = end = endmatch.end(0) | |
193 | yield (STRING, contstr + line[:end], | |
194 | strstart, (lnum, end), contline + line) | |
195 | contstr, needcont = '', 0 | |
196 | contline = None | |
197 | elif needcont and line[-2:] != '\\\n' and line[-3:] != '\\\r\n': | |
198 | yield (ERRORTOKEN, contstr + line, | |
199 | strstart, (lnum, len(line)), contline) | |
200 | contstr = '' | |
201 | contline = None | |
202 | continue | |
203 | else: | |
204 | contstr = contstr + line | |
205 | contline = contline + line | |
206 | continue | |
207 | ||
208 | elif parenlev == 0 and not continued: # new statement | |
209 | if not line: break | |
210 | column = 0 | |
211 | while pos < max: # measure leading whitespace | |
212 | if line[pos] == ' ': column = column + 1 | |
213 | elif line[pos] == '\t': column = (column/tabsize + 1)*tabsize | |
214 | elif line[pos] == '\f': column = 0 | |
215 | else: break | |
216 | pos = pos + 1 | |
217 | if pos == max: break | |
218 | ||
219 | if line[pos] in '#\r\n': # skip comments or blank lines | |
220 | yield ((NL, COMMENT)[line[pos] == '#'], line[pos:], | |
221 | (lnum, pos), (lnum, len(line)), line) | |
222 | continue | |
223 | ||
224 | if column > indents[-1]: # count indents or dedents | |
225 | indents.append(column) | |
226 | yield (INDENT, line[:pos], (lnum, 0), (lnum, pos), line) | |
227 | while column < indents[-1]: | |
228 | if column not in indents: | |
229 | raise IndentationError( | |
230 | "unindent does not match any outer indentation level") | |
231 | indents = indents[:-1] | |
232 | yield (DEDENT, '', (lnum, pos), (lnum, pos), line) | |
233 | ||
234 | else: # continued statement | |
235 | if not line: | |
236 | raise TokenError, ("EOF in multi-line statement", (lnum, 0)) | |
237 | continued = 0 | |
238 | ||
239 | while pos < max: | |
240 | pseudomatch = pseudoprog.match(line, pos) | |
241 | if pseudomatch: # scan for tokens | |
242 | start, end = pseudomatch.span(1) | |
243 | spos, epos, pos = (lnum, start), (lnum, end), end | |
244 | token, initial = line[start:end], line[start] | |
245 | ||
246 | if initial in numchars or \ | |
247 | (initial == '.' and token != '.'): # ordinary number | |
248 | yield (NUMBER, token, spos, epos, line) | |
249 | elif initial in '\r\n': | |
250 | yield (parenlev > 0 and NL or NEWLINE, | |
251 | token, spos, epos, line) | |
252 | elif initial == '#': | |
253 | yield (COMMENT, token, spos, epos, line) | |
254 | elif token in triple_quoted: | |
255 | endprog = endprogs[token] | |
256 | endmatch = endprog.match(line, pos) | |
257 | if endmatch: # all on one line | |
258 | pos = endmatch.end(0) | |
259 | token = line[start:pos] | |
260 | yield (STRING, token, spos, (lnum, pos), line) | |
261 | else: | |
262 | strstart = (lnum, start) # multiple lines | |
263 | contstr = line[start:] | |
264 | contline = line | |
265 | break | |
266 | elif initial in single_quoted or \ | |
267 | token[:2] in single_quoted or \ | |
268 | token[:3] in single_quoted: | |
269 | if token[-1] == '\n': # continued string | |
270 | strstart = (lnum, start) | |
271 | endprog = (endprogs[initial] or endprogs[token[1]] or | |
272 | endprogs[token[2]]) | |
273 | contstr, needcont = line[start:], 1 | |
274 | contline = line | |
275 | break | |
276 | else: # ordinary string | |
277 | yield (STRING, token, spos, epos, line) | |
278 | elif initial in namechars: # ordinary name | |
279 | yield (NAME, token, spos, epos, line) | |
280 | elif initial == '\\': # continued stmt | |
281 | continued = 1 | |
282 | else: | |
283 | if initial in '([{': parenlev = parenlev + 1 | |
284 | elif initial in ')]}': parenlev = parenlev - 1 | |
285 | yield (OP, token, spos, epos, line) | |
286 | else: | |
287 | yield (ERRORTOKEN, line[pos], | |
288 | (lnum, pos), (lnum, pos+1), line) | |
289 | pos = pos + 1 | |
290 | ||
291 | for indent in indents[1:]: # pop remaining indent levels | |
292 | yield (DEDENT, '', (lnum, 0), (lnum, 0), '') | |
293 | yield (ENDMARKER, '', (lnum, 0), (lnum, 0), '') | |
294 | ||
295 | if __name__ == '__main__': # testing | |
296 | import sys | |
297 | if len(sys.argv) > 1: tokenize(open(sys.argv[1]).readline) | |
298 | else: tokenize(sys.stdin.readline) |