varexpand: optimize access to current char
diff --git a/pym/portage/util/__init__.py b/pym/portage/util/__init__.py
index 3e7187c..d6ac46c 100644
--- a/pym/portage/util/__init__.py
+++ b/pym/portage/util/__init__.py
@@ -660,14 +660,15 @@
This would be a good bunch of code to port to C.
"""
numvars=0
- mystring=" "+mystring
#in single, double quotes
insing=0
indoub=0
- pos=1
+ pos = 0
+ length = len(mystring)
newstring = []
- while (pos<len(mystring)):
- if (mystring[pos]=="'") and (mystring[pos-1]!="\\"):
+ while pos < length:
+ current = mystring[pos]
+ if current == "'":
if (indoub):
newstring.append("'")
else:
@@ -675,7 +676,7 @@
insing=not insing
pos=pos+1
continue
- elif (mystring[pos]=='"') and (mystring[pos-1]!="\\"):
+ elif current == '"':
if (insing):
newstring.append('"')
else:
@@ -685,11 +686,11 @@
continue
if (not insing):
#expansion time
- if (mystring[pos]=="\n"):
+ if current == "\n":
#convert newlines to spaces
newstring.append(" ")
- pos=pos+1
- elif (mystring[pos]=="\\"):
+ pos += 1
+ elif current == "\\":
# For backslash expansion, this function used to behave like
# echo -e, but that's not needed for our purposes. We want to
# behave like bash does when expanding a variable assignment
@@ -699,19 +700,27 @@
# escaped quotes here, since getconfig() uses shlex
# to handle that earlier.
if (pos+1>=len(mystring)):
- newstring.append(mystring[pos])
+ newstring.append(current)
break
else:
- a = mystring[pos + 1]
- pos = pos + 2
- if a in ("\\", "$"):
- newstring.append(a)
- elif a == "\n":
+ current = mystring[pos + 1]
+ pos += 2
+ if current == "$":
+ newstring.append(current)
+ elif current == "\\":
+ newstring.append(current)
+ # BUG: This spot appears buggy, but it's intended to
+ # be bug-for-bug compatible with existing behavior.
+ if pos < length and \
+ mystring[pos] in ("'", '"', "$"):
+ newstring.append(mystring[pos])
+ pos += 1
+ elif current == "\n":
pass
else:
newstring.append(mystring[pos - 2:pos])
continue
- elif (mystring[pos]=="$") and (mystring[pos-1]!="\\"):
+ elif current == "$":
pos=pos+1
if mystring[pos]=="{":
pos=pos+1
@@ -754,11 +763,11 @@
if myvarname in mydict:
newstring.append(mydict[myvarname])
else:
- newstring.append(mystring[pos])
- pos=pos+1
+ newstring.append(current)
+ pos += 1
else:
- newstring.append(mystring[pos])
- pos=pos+1
+ newstring.append(current)
+ pos += 1
return "".join(newstring)
