[GR-17150] Implemented charmap_build for codecs

PullRequest: graalpython/585

Author: timfel

graalpython/com.oracle.graal.python.test/src/tests/test_codecs.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2018, Oracle and/or its affiliates.
+# Copyright (c) 2019, Oracle and/or its affiliates.
 # Copyright (C) 1996-2017 Python Software Foundation
 #
 # Licensed under the PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
@@ -172,3 +172,9 @@ def test_escape_decode(self):
         check(br"[\x410]", "[A0]")
         check(br"\u20ac", "\u20ac")
         check(br"\U0001d120", "\U0001d120")
+
+
+def test_charmap_build():
+    import codecs
+    assert codecs.charmap_build(u'123456') == {49: 0, 50: 1, 51: 2,
+                                               52: 3, 53: 4, 54: 5}

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/CodecsModuleBuiltins.java

@@ -628,4 +628,31 @@ Object lookup(String encoding) {
             }
         }
     }
+
+    // _codecs.lookup(name)
+    @Builtin(name = "charmap_build", minNumOfPositionalArgs = 1)
+    @GenerateNodeFactory
+    abstract static class CharmapBuildNode extends PythonBuiltinNode {
+        // This is replaced in the core _codecs.py with the full functionality
+        @Specialization
+        Object lookup(String chars) {
+            Map<Integer, Integer> charmap = createMap(chars);
+            return factory().createDict(charmap);
+        }
+
+        @TruffleBoundary
+        private static Map<Integer, Integer> createMap(String chars) {
+            Map<Integer, Integer> charmap = new HashMap<>();
+            int pos = 0;
+            int num = 0;
+
+            while (pos < chars.length()) {
+                int charid = Character.codePointAt(chars, pos);
+                charmap.put(charid, num);
+                pos += Character.charCount(charid);
+                num++;
+            }
+            return charmap;
+        }
+    }
 }

graalpython/lib-graalpython/_codecs.py

@@ -281,11 +281,6 @@ def charmap_decode(string, errors=None, mapping=None):
     return __truffle_decode(string, "cp437", errors)
 
 
-@__builtin__
-def charmap_build(mapping):
-    raise NotImplementedError("charmap_build")
-
-
 @__builtin__
 def readbuffer_encode(data, errors=None):
     raise NotImplementedError("readbuffer_encode")