# HG changeset patch
# User Franz Glasner <fzglas.hg@dom66.de>
# Date 1639919428 -3600
# Node ID 3387a9d5fb126f7b387f06a3cbf91e44ab512438
# Parent  d803321d927bbb17cd9b7243291e340e62ad20bb
Performance: compute the length of the constant input strinc only once and compute the new rest earlier and use the computed value also in comparisons

diff -r d803321d927b -r 3387a9d5fb12 configmix/config.py
--- a/configmix/config.py	Sun Dec 19 14:05:14 2021 +0100
+++ b/configmix/config.py	Sun Dec 19 14:10:28 2021 +0100
@@ -746,6 +746,7 @@
         start = s.find(_STARTTOK, 0)
         if start < 0:
             return s
+        len_s = len(s)
         res = []
         res_append = res.append
         rest = 0
@@ -773,11 +774,12 @@
                               UserWarning,
                               stacklevel=1)
                 raise
+            rest = end + 2
             #
             # Dont apply and type conversions to the variable value if
             # the whole `s` is just one expansion
             #
-            if (start == 0) and (end + 2 == len(s)):
+            if (start == 0) and (rest == len_s):
                 return varvalue
             if not varvalue:
                 # None and/or empty str are handled equally here
@@ -785,7 +787,6 @@
             else:
                 res_append(str_and_u(varvalue))
             # don't re-evaluate because `self.getvar_s()` expands already
-            rest = end + 2
             start = s.find(_STARTTOK, rest)
         res_append(s[rest:])
         return _EMPTY_STR.join(res)