Adapt distrib/gen_gps.py to python3, minor formatting.

This comes from the GitHub pull request #50
no-tn-check

Change-Id: I0f011449d5d4c3f71e10ee8620f2013ec826cb49

Author: t-14

distrib/gen_gps.py

@@ -4,43 +4,46 @@
 import os.path
 import re
 
-pkg_re = re.compile("^(private)?\s*package\s*(\S+)")
+pkg_re = re.compile(r"^(private)?\s*package\s*(\S+)")
 
 
 def recursive_ls(dir):
     """Return the list of ads files in dir and its subdirs"""
     result = set()
     for f in os.listdir(dir):
+        path = os.path.join(dir, f)
         if f.endswith(".ads") \
            and f.startswith("gnatcoll-"):
 
             private = False
             pkg = ""
-            for l in file(os.path.join(dir, f)).readlines():
-                m = pkg_re.search(l)
-                if m:
-                    private = m.group(1)
-                    pkg = m.group(2)
-                    break
+            with open(path) as h:
+                for line in h.readlines():
+                    m = pkg_re.search(line)
+                    if m:
+                        private = m.group(1)
+                        pkg = m.group(2)
+                        break
 
             if not private:
                 result.add((pkg, os.path.splitext(f)[0]))
 
-        elif os.path.isdir(os.path.join(dir, f)):
-            result = result.union(recursive_ls(os.path.join(dir, f)))
+        elif os.path.isdir(path):
+            result = result.union(recursive_ls(path))
 
     return result
 
+
 list = recursive_ls("../src")
-out = file("gnatcoll/runtime.py", "wb")
-out.write("""XML = r'''<?xml version="1.0"?>
+with open("gnatcoll/runtime.py", "w") as out:
+    out.write("""XML = r'''<?xml version="1.0"?>
 <GPS>
 """)
 
-for pkg, f in sorted(list):
-    if '__' in f:
-        # An internal package with a specific naming scheme
-        continue
+    for pkg, f in sorted(list):
+        if '__' in f:
+            # An internal package with a specific naming scheme
+            continue
 
     menu = pkg.replace(".", "/").replace("_", "__")
 
@@ -61,8 +64,7 @@ def recursive_ls(dir):
 
 """ % {"file": f, "menu": menu, "package": pkg})
 
-out.write("""</GPS>'''
+    out.write("""</GPS>'''
 import GPS
 GPS.parse_xml(XML)
 """)
-out.close()