Add genericpath module (#359)

Author: m4ns0ur

Makefile

@@ -97,6 +97,7 @@ STDLIB_TESTS := \
   test/test_datetime \
   test/test_dict \
   test/test_fpformat \
+  test/test_genericpath \
   test/test_list \
   test/test_md5 \
   test/test_mimetools \

third_party/stdlib/genericpath.py

@@ -0,0 +1,113 @@
+"""
+Path operations common to more than one OS
+Do not use directly.  The OS specific modules import the appropriate
+functions from this module themselves.
+"""
+import os
+import stat
+
+__all__ = ['commonprefix', 'exists', 'getatime', 'getctime', 'getmtime',
+           'getsize', 'isdir', 'isfile']
+
+
+try:
+    _unicode = unicode
+except NameError:
+    # If Python is built without Unicode support, the unicode type
+    # will not exist. Fake one.
+    class _unicode(object):
+        pass
+
+# Does a path exist?
+# This is false for dangling symbolic links on systems that support them.
+def exists(path):
+    """Test whether a path exists.  Returns False for broken symbolic links"""
+    try:
+        os.stat(path)
+    except os.error:
+        return False
+    return True
+
+
+# This follows symbolic links, so both islink() and isdir() can be true
+# for the same path on systems that support symlinks
+def isfile(path):
+    """Test whether a path is a regular file"""
+    try:
+        st = os.stat(path)
+    except os.error:
+        return False
+    return stat.S_ISREG(st.st_mode)
+
+
+# Is a path a directory?
+# This follows symbolic links, so both islink() and isdir()
+# can be true for the same path on systems that support symlinks
+def isdir(s):
+    """Return true if the pathname refers to an existing directory."""
+    try:
+        st = os.stat(s)
+    except os.error:
+        return False
+    return stat.S_ISDIR(st.st_mode)
+
+
+def getsize(filename):
+    """Return the size of a file, reported by os.stat()."""
+    return os.stat(filename).st_size
+
+
+def getmtime(filename):
+    """Return the last modification time of a file, reported by os.stat()."""
+    return os.stat(filename).st_mtime
+
+
+def getatime(filename):
+    """Return the last access time of a file, reported by os.stat()."""
+    return os.stat(filename).st_atime
+
+
+def getctime(filename):
+    """Return the metadata change time of a file, reported by os.stat()."""
+    return os.stat(filename).st_ctime
+
+
+# Return the longest prefix of all list elements.
+def commonprefix(m):
+    "Given a list of pathnames, returns the longest common leading component"
+    if not m: return ''
+    s1 = min(m)
+    s2 = max(m)
+    for i, c in enumerate(s1):
+        if c != s2[i]:
+            return s1[:i]
+    return s1
+
+# Split a path in root and extension.
+# The extension is everything starting at the last dot in the last
+# pathname component; the root is everything before that.
+# It is always true that root + ext == p.
+
+# Generic implementation of splitext, to be parametrized with
+# the separators
+def _splitext(p, sep, altsep, extsep):
+    """Split the extension from a pathname.
+
+    Extension is everything from the last dot to the end, ignoring
+    leading dots.  Returns "(root, ext)"; ext may be empty."""
+
+    sepIndex = p.rfind(sep)
+    if altsep:
+        altsepIndex = p.rfind(altsep)
+        sepIndex = max(sepIndex, altsepIndex)
+
+    dotIndex = p.rfind(extsep)
+    if dotIndex > sepIndex:
+        # skip all leading dots
+        filenameIndex = sepIndex + 1
+        while filenameIndex < dotIndex:
+            if p[filenameIndex] != extsep:
+                return p[:dotIndex], p[dotIndex:]
+            filenameIndex += 1
+
+    return p, ''