summaryrefslogtreecommitdiff
path: root/cheetah/SourceReader.py
blob: 7a088372a13cabd3b1cbdfd3163725395fbc0503 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
"""SourceReader class for Cheetah's Parser and CodeGenerator
"""
import re
import sys

EOLre = re.compile(r'[ \f\t]*(?:\r\n|\r|\n)')
EOLZre = re.compile(r'(?:\r\n|\r|\n|\Z)')
ENCODINGsearch = re.compile("coding[=:]\s*([-\w.]+)").search

class Error(Exception):
    pass
                                
class SourceReader(object):
    def __init__(self, src, filename=None, breakPoint=None, encoding=None):

        ## @@TR 2005-01-17: the following comes from a patch Terrel Shumway
        ## contributed to add unicode support to the reading of Cheetah source
        ## files with dynamically compiled templates. All the existing unit
        ## tests pass but, it needs more testing and some test cases of its
        ## own. My instinct is to move this up into the code that passes in the
        ## src string rather than leaving it here.  As implemented here it
        ## forces all src strings to unicode, which IMO is not what we want.
        #  if encoding is None:
        #      # peek at the encoding in the first two lines
        #      m = EOLZre.search(src)
        #      pos = m.end()
        #      if pos<len(src):
        #          m = EOLZre.search(src,pos)
        #          pos = m.end()
        #      m = ENCODINGsearch(src,0,pos)
        #      if m:
        #          encoding = m.group(1)
        #      else:
        #          encoding  = sys.getfilesystemencoding()
        #  self._encoding = encoding
        #  if type(src) is not unicode:
        #      src = src.decode(encoding)
        ## end of Terrel's patch

        self._src = src
        self._filename = filename

        self._srcLen = len(src)
        if breakPoint == None:
            self._breakPoint = self._srcLen
        else:
            self.setBreakPoint(breakPoint)
        self._pos = 0
        self._bookmarks = {}
        self._posTobookmarkMap = {}

        ## collect some meta-information
        self._EOLs = []
        pos = 0
        while pos < len(self):
            EOLmatch = EOLZre.search(src, pos)
            self._EOLs.append(EOLmatch.start())
            pos = EOLmatch.end()
            
        self._BOLs = []
        for pos in self._EOLs:
            BOLpos = self.findBOL(pos)
            self._BOLs.append(BOLpos)
        
    def src(self):
        return self._src

    def filename(self):
        return self._filename

    def __len__(self):
        return self._breakPoint
    
    def __getitem__(self, i):
        self.checkPos(i)
        return self._src[i]
    
    def __getslice__(self, i, j):
        i = max(i, 0); j = max(j, 0)
        return self._src[i:j]

    def splitlines(self):
        if not hasattr(self, '_srcLines'):                
            self._srcLines = self._src.splitlines()
        return self._srcLines

    def lineNum(self, pos=None):
        if pos == None:
            pos = self._pos
            
        for i in range(len(self._BOLs)):
            if pos >= self._BOLs[i] and pos <= self._EOLs[i]:
                return i
            
    def getRowCol(self, pos=None):
        if pos == None:
            pos = self._pos
        lineNum = self.lineNum(pos)
        BOL, EOL = self._BOLs[lineNum], self._EOLs[lineNum]
        return lineNum+1, pos-BOL+1
            
    def getRowColLine(self, pos=None):
        if pos == None:
            pos = self._pos
        row, col = self.getRowCol(pos)    
        return row, col, self.splitlines()[row-1]

    def getLine(self, pos):
        if pos == None:
            pos = self._pos
        lineNum = self.lineNum(pos)
        return self.splitlines()[lineNum]
        
    def pos(self):
        return self._pos
    
    def setPos(self, pos):
        self.checkPos(pos)
        self._pos = pos


    def validPos(self, pos):
        return pos <= self._breakPoint and pos >=0 
                    
    def checkPos(self, pos):
        if not pos <= self._breakPoint:
            raise Error("pos (" + str(pos) + ") is invalid: beyond the stream's end (" +
                        str(self._breakPoint-1) + ")" )
        elif not pos >=0:
            raise Error("pos (" + str(pos) + ") is invalid: less than 0" )

    def breakPoint(self):
        return self._breakPoint
    
    def setBreakPoint(self, pos):
        if pos > self._srcLen:
            raise Error("New breakpoint (" + str(pos) +
                        ") is invalid: beyond the end of stream's source string (" +
                        str(self._srcLen) + ")" )
        elif not pos >= 0:
            raise Error("New breakpoint (" + str(pos) + ") is invalid: less than 0" )        
        
        self._breakPoint = pos

    def setBookmark(self, name):
        self._bookmarks[name] = self._pos
        self._posTobookmarkMap[self._pos] = name

    def hasBookmark(self, name):
        return name in self._bookmarks
    
    def gotoBookmark(self, name):
        if not self.hasBookmark(name):
            raise Error("Invalid bookmark (" + name + ") is invalid: does not exist")
        pos = self._bookmarks[name]
        if not self.validPos(pos):
            raise Error("Invalid bookmark (" + name + ', '+
                        str(pos) + ") is invalid: pos is out of range" )        
        self._pos = pos

    def atEnd(self):
        return self._pos >= self._breakPoint

    def atStart(self):
        return self._pos == 0
                          
    def peek(self, offset=0):
        self.checkPos(self._pos+offset)
        pos = self._pos + offset
        return self._src[pos]

    def getc(self):
        pos = self._pos
        if self.validPos(pos+1):
            self._pos += 1
        return self._src[pos]

    def ungetc(self, c=None):
        if not self.atStart():
            raise Error('Already at beginning of stream')

        self._pos -= 1
        if not c==None:
            self._src[self._pos] = c

    def advance(self, offset=1):
        self.checkPos(self._pos + offset)
        self._pos += offset

    def rev(self, offset=1):
        self.checkPos(self._pos - offset)
        self._pos -= offset
               
    def read(self, offset):
        self.checkPos(self._pos + offset)
        start = self._pos
        self._pos += offset
        return self._src[start:self._pos]

    def readTo(self, to, start=None):
        self.checkPos(to)
        if start == None:
            start = self._pos
        self._pos = to
        return self._src[start:to]

        
    def readToEOL(self, start=None, gobble=True):
        EOLmatch = EOLZre.search(self.src(), self.pos())
        if gobble:
            pos = EOLmatch.end()
        else:
            pos = EOLmatch.start()
        return self.readTo(to=pos, start=start)
    

    def find(self, it, pos=None):
        if pos == None:
            pos = self._pos
        return self._src.find(it, pos )

    def startswith(self, it, pos=None):
        if self.find(it, pos) == self.pos():
            return True
        else:
            return False
                    
    def rfind(self, it, pos):
        if pos == None:
            pos = self._pos
        return self._src.rfind(it, pos)
        
    def findBOL(self, pos=None):
        if pos == None:
            pos = self._pos
        src = self.src()
        return max(src.rfind('\n', 0, pos)+1, src.rfind('\r', 0, pos)+1, 0)
        
    def findEOL(self, pos=None, gobble=False):
        if pos == None:
            pos = self._pos

        match = EOLZre.search(self.src(), pos)
        if gobble:
            return match.end()
        else:
            return match.start()
    
    def isLineClearToPos(self, pos=None):
        if pos == None:
            pos = self.pos()
        self.checkPos(pos)            
        src = self.src()
        BOL = self.findBOL()
        return BOL == pos or src[BOL:pos].isspace()

    def matches(self, strOrRE):
        if isinstance(strOrRE, (str, unicode)):
            return self.startswith(strOrRE, pos=self.pos())
        else: # assume an re object
            return strOrRE.match(self.src(), self.pos())

    def matchWhiteSpace(self, WSchars=' \f\t'):
        return (not self.atEnd()) and  self.peek() in WSchars

    def getWhiteSpace(self, max=None, WSchars=' \f\t'):
        if not self.matchWhiteSpace(WSchars):
            return ''
        start = self.pos()
        breakPoint = self.breakPoint()
        if max is not None:
            breakPoint = min(breakPoint, self.pos()+max)
        while self.pos() < breakPoint:
            self.advance()
            if not self.matchWhiteSpace(WSchars):
                break
        return self.src()[start:self.pos()]

    def matchNonWhiteSpace(self, WSchars=' \f\t\n\r'):
        return self.atEnd() or not self.peek() in WSchars

    def getNonWhiteSpace(self, WSchars=' \f\t\n\r'):
        if not self.matchNonWhiteSpace(WSchars):
            return ''
        start = self.pos()
        while self.pos() < self.breakPoint():
            self.advance()
            if not self.matchNonWhiteSpace(WSchars):
                break
        return self.src()[start:self.pos()]