summaryrefslogtreecommitdiffstats
path: root/Lib/idlelib/SearchEngine.py
blob: e37975104abcf349bec3bf1aa10b9b25f89c94ba (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
import string
import re
from Tkinter import *
import tkMessageBox

def get(root):
    if not hasattr(root, "_searchengine"):
        root._searchengine = SearchEngine(root)
        # XXX This will never garbage-collect -- who cares
    return root._searchengine

class SearchEngine:

    def __init__(self, root):
        self.root = root
        # State shared by search, replace, and grep;
        # the search dialogs bind these to UI elements.
        self.patvar = StringVar(root)           # search pattern
        self.revar = BooleanVar(root)           # regular expression?
        self.casevar = BooleanVar(root)         # match case?
        self.wordvar = BooleanVar(root)         # match whole word?
        self.wrapvar = BooleanVar(root)         # wrap around buffer?
        self.wrapvar.set(1)                     # (on by default)
        self.backvar = BooleanVar(root)         # search backwards?

    # Access methods

    def getpat(self):
        return self.patvar.get()

    def setpat(self, pat):
        self.patvar.set(pat)

    def isre(self):
        return self.revar.get()

    def iscase(self):
        return self.casevar.get()

    def isword(self):
        return self.wordvar.get()

    def iswrap(self):
        return self.wrapvar.get()

    def isback(self):
        return self.backvar.get()

    # Higher level access methods

    def getcookedpat(self):
        pat = self.getpat()
        if not self.isre():
            pat = re.escape(pat)
        if self.isword():
            pat = r"\b%s\b" % pat
        return pat

    def getprog(self):
        pat = self.getpat()
        if not pat:
            self.report_error(pat, "Empty regular expression")
            return None
        pat = self.getcookedpat()
        flags = 0
        if not self.iscase():
            flags = flags | re.IGNORECASE
        try:
            prog = re.compile(pat, flags)
        except re.error, what:
            try:
                msg, col = what
            except:
                msg = str(what)
                col = -1
            self.report_error(pat, msg, col)
            return None
        return prog

    def report_error(self, pat, msg, col=-1):
        # Derived class could overrid this with something fancier
        msg = "Error: " + str(msg)
        if pat:
            msg = msg + "\np\Pattern: " + str(pat)
        if col >= 0:
            msg = msg + "\nOffset: " + str(col)
        tkMessageBox.showerror("Regular expression error",
                               msg, master=self.root)

    def setcookedpat(self, pat):
        if self.isre():
            pat = re.escape(pat)
        self.setpat(pat)

    def search_text(self, text, prog=None, ok=0):
        """Search a text widget for the pattern.

        If prog is given, it should be the precompiled pattern.
        Return a tuple (lineno, matchobj); None if not found.

        This obeys the wrap and direction (back) settings.

        The search starts at the selection (if there is one) or
        at the insert mark (otherwise).  If the search is forward,
        it starts at the right of the selection; for a backward
        search, it starts at the left end.  An empty match exactly
        at either end of the selection (or at the insert mark if
        there is no selection) is ignored  unless the ok flag is true
        -- this is done to guarantee progress.

        If the search is allowed to wrap around, it will return the
        original selection if (and only if) it is the only match.

        """
        if not prog:
            prog = self.getprog()
            if not prog:
                return None # Compilation failed -- stop
        wrap = self.wrapvar.get()
        first, last = get_selection(text)
        if self.isback():
            if ok:
                start = last
            else:
                start = first
            line, col = get_line_col(start)
            res = self.search_backward(text, prog, line, col, wrap, ok)
        else:
            if ok:
                start = first
            else:
                start = last
            line, col = get_line_col(start)
            res = self.search_forward(text, prog, line, col, wrap, ok)
        return res

    def search_forward(self, text, prog, line, col, wrap, ok=0):
        wrapped = 0
        startline = line
        chars = text.get("%d.0" % line, "%d.0" % (line+1))
        while chars:
            m = prog.search(chars[:-1], col)
            if m:
                if ok or m.end() > col:
                    return line, m
            line = line + 1
            if wrapped and line > startline:
                break
            col = 0
            ok = 1
            chars = text.get("%d.0" % line, "%d.0" % (line+1))
            if not chars and wrap:
                wrapped = 1
                wrap = 0
                line = 1
                chars = text.get("1.0", "2.0")
        return None

    def search_backward(self, text, prog, line, col, wrap, ok=0):
        wrapped = 0
        startline = line
        chars = text.get("%d.0" % line, "%d.0" % (line+1))
        while 1:
            m = search_reverse(prog, chars[:-1], col)
            if m:
                if ok or m.start() < col:
                    return line, m
            line = line - 1
            if wrapped and line < startline:
                break
            ok = 1
            if line <= 0:
                if not wrap:
                    break
                wrapped = 1
                wrap = 0
                pos = text.index("end-1c")
                line, col = map(int, string.split(pos, "."))
            chars = text.get("%d.0" % line, "%d.0" % (line+1))
            col = len(chars) - 1
        return None

# Helper to search backwards in a string.
# (Optimized for the case where the pattern isn't found.)

def search_reverse(prog, chars, col):
    m = prog.search(chars)
    if not m:
        return None
    found = None
    i, j = m.span()
    while i < col and j <= col:
        found = m
        if i == j:
            j = j+1
        m = prog.search(chars, j)
        if not m:
            break
        i, j = m.span()
    return found

# Helper to get selection end points, defaulting to insert mark.
# Return a tuple of indices ("line.col" strings).

def get_selection(text):
    try:
        first = text.index("sel.first")
        last = text.index("sel.last")
    except TclError:
        first = last = None
    if not first:
        first = text.index("insert")
    if not last:
        last = first
    return first, last

# Helper to parse a text index into a (line, col) tuple.

def get_line_col(index):
    line, col = map(int, string.split(index, ".")) # Fails on invalid index
    return line, col