Small performance tuning printable_name and normalize.

These utils show on top when profiling. Now they are a (very) little
faster.

src/robot/utils/misc.py

@@ -66,35 +66,33 @@ def printable_name(string, code_style=False):
     if code_style and '_' in string:
         string = string.replace('_', ' ')
     parts = string.split()
-    if not parts:
-        return ''
     if code_style and len(parts) == 1 \
             and not (string.isalpha() and string.islower()):
-        parts = _camelCaseSplit(list(parts[0]))
+        parts = _split_camel_case(parts[0])
     return ' '.join(part[0].upper() + part[1:] for part in parts)
 
 
-def _camelCaseSplit(chars):
+def _split_camel_case(string):
+    tokens = []
     token = []
-    for prev, char, next in zip([''] + chars, chars, chars[1:] + ['']):
-        if _isCamelCaseBoundary(prev, char, next):
+    for prev, char, next in zip(' ' + string, string, string[1:] + ' '):
+        if _is_camel_case_boundary(prev, char, next):
             if token:
-                yield ''.join(token)
+                tokens.append(''.join(token))
             token = [char]
         else:
             token.append(char)
     if token:
-        yield ''.join(token)
+        tokens.append(''.join(token))
+    return tokens
 
 
-def _isCamelCaseBoundary(prev, char, next):
+def _is_camel_case_boundary(prev, char, next):
     if prev.isdigit():
         return not char.isdigit()
     if char.isupper():
         return next.islower() or prev.isalpha() and not prev.isupper()
-    if char.isdigit():
-        return not prev.isdigit()
-    return False
+    return char.isdigit()
 
 
 def plural_or_not(item):

src/robot/utils/normalizing.py

@@ -16,7 +16,7 @@
 import sys
 from collections import MutableMapping
 
-from .platform import PY3
+from .platform import PY3, IRONPYTHON
 from .robottypes import is_dict_like
 
 
@@ -35,14 +35,16 @@ def normalize(string, ignore=(), caseless=True, spaceless=True):
     if caseless:
         string = lower(string)
         ignore = [lower(i) for i in ignore]
-    for ign in ignore:
-        if ign in string:  # performance optimization
-            string = string.replace(ign, empty)
+    # both if statements below enhance performance a little
+    if ignore:
+        for ign in ignore:
+            if ign in string:
+                string = string.replace(ign, empty)
     return string
 
 
 # http://ironpython.codeplex.com/workitem/33133
-if sys.platform == 'cli' and sys.version_info < (2, 7, 5):
+if IRONPYTHON and sys.version_info < (2, 7, 5):
     def lower(string):
         return ('A' + string).lower()[1:]
 else: