bpo-36390: simplify classifyws(), rename it and add unit tests (GH-14500)
diff --git a/Lib/idlelib/editor.py b/Lib/idlelib/editor.py
index 606de71..9b5364f 100644
--- a/Lib/idlelib/editor.py
+++ b/Lib/idlelib/editor.py
@@ -1281,7 +1281,7 @@
text.delete(first, last)
text.mark_set("insert", first)
prefix = text.get("insert linestart", "insert")
- raw, effective = classifyws(prefix, self.tabwidth)
+ raw, effective = get_line_indent(prefix, self.tabwidth)
if raw == len(prefix):
# only whitespace to the left
self.reindent_to(effective + self.indentwidth)
@@ -1415,7 +1415,7 @@
for pos in range(len(lines)):
line = lines[pos]
if line:
- raw, effective = classifyws(line, self.tabwidth)
+ raw, effective = get_line_indent(line, self.tabwidth)
effective = effective + self.indentwidth
lines[pos] = self._make_blanks(effective) + line[raw:]
self.set_region(head, tail, chars, lines)
@@ -1426,7 +1426,7 @@
for pos in range(len(lines)):
line = lines[pos]
if line:
- raw, effective = classifyws(line, self.tabwidth)
+ raw, effective = get_line_indent(line, self.tabwidth)
effective = max(effective - self.indentwidth, 0)
lines[pos] = self._make_blanks(effective) + line[raw:]
self.set_region(head, tail, chars, lines)
@@ -1461,7 +1461,7 @@
for pos in range(len(lines)):
line = lines[pos]
if line:
- raw, effective = classifyws(line, tabwidth)
+ raw, effective = get_line_indent(line, tabwidth)
ntabs, nspaces = divmod(effective, tabwidth)
lines[pos] = '\t' * ntabs + ' ' * nspaces + line[raw:]
self.set_region(head, tail, chars, lines)
@@ -1575,8 +1575,8 @@
def guess_indent(self):
opener, indented = IndentSearcher(self.text, self.tabwidth).run()
if opener and indented:
- raw, indentsmall = classifyws(opener, self.tabwidth)
- raw, indentlarge = classifyws(indented, self.tabwidth)
+ raw, indentsmall = get_line_indent(opener, self.tabwidth)
+ raw, indentlarge = get_line_indent(indented, self.tabwidth)
else:
indentsmall = indentlarge = 0
return indentlarge - indentsmall
@@ -1585,23 +1585,16 @@
def index2line(index):
return int(float(index))
-# Look at the leading whitespace in s.
-# Return pair (# of leading ws characters,
-# effective # of leading blanks after expanding
-# tabs to width tabwidth)
-def classifyws(s, tabwidth):
- raw = effective = 0
- for ch in s:
- if ch == ' ':
- raw = raw + 1
- effective = effective + 1
- elif ch == '\t':
- raw = raw + 1
- effective = (effective // tabwidth + 1) * tabwidth
- else:
- break
- return raw, effective
+_line_indent_re = re.compile(r'[ \t]*')
+def get_line_indent(line, tabwidth):
+ """Return a line's indentation as (# chars, effective # of spaces).
+
+ The effective # of spaces is the length after properly "expanding"
+ the tabs into spaces, as done by str.expandtabs(tabwidth).
+ """
+ m = _line_indent_re.match(line)
+ return m.end(), len(m.group().expandtabs(tabwidth))
class IndentSearcher(object):