# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1481417394 -3600
# Node ID 0613a74e6acae0f4e28479a7b8fc5b46793da1ef
# Parent  ff3ebfe09afc76e3002252684ec1b3822642cb43
Implemented hex and oct, adding tests.

diff -r ff3ebfe09afc -r 0613a74e6aca lib/__builtins__/character.py
--- a/lib/__builtins__/character.py	Sun Dec 11 01:37:33 2016 +0100
+++ b/lib/__builtins__/character.py	Sun Dec 11 01:49:54 2016 +0100
@@ -22,8 +22,51 @@
 from native import str_ord
 
 def chr(i): pass
-def hex(number): pass
-def oct(number): pass
+
+_hexdigits = "0123456789abcdef"
+
+def _base(number, base, prefix=""):
+
+    """
+    Return 'number' encoded in the given 'base', prefixed with 'prefix'.
+    """
+
+    if number < 0:
+        number = -number
+        sign = "-"
+    else:
+        sign = ""
+
+    digits = []
+
+    while number:
+        digits.append(_hexdigits[number % base])
+        number = number / base
+
+    digits.append(prefix)
+
+    if sign:
+        digits.append(sign)
+
+    return "".join(reversed(digits))
+
+def hex(number, prefix="0x"):
+
+    """
+    Return 'number' encoded as a hexadecimal (base 16) value, prefixed with
+    'prefix' ("0x" by default).
+    """
+
+    return _base(number, 16, prefix)
+
+def oct(number, prefix="0"):
+
+    """
+    Return 'number' encoded as an octal (base 8) value, prefixed with 'prefix'
+    ("0" by default).
+    """
+
+    return _base(number, 8, prefix)
 
 def ord(c):
 
diff -r ff3ebfe09afc -r 0613a74e6aca tests/numbers.py
--- a/tests/numbers.py	Sun Dec 11 01:37:33 2016 +0100
+++ b/tests/numbers.py	Sun Dec 11 01:49:54 2016 +0100
@@ -7,9 +7,13 @@
 
 i = 2 ** 30
 print i                                 # 1073741824
+print hex(i)                            # 0x40000000
+print oct(i)                            # 010000000000
 
 j = -2 ** 30
 print j                                 # -1073741824
+print hex(j)                            # -0x40000000
+print oct(j)                            # -010000000000
 
 print i + j                             # 0
 
@@ -33,3 +37,6 @@
 print ~j                                # 1073741823
 print i & ~j                            # 0
 print i - 1 & ~j                        # 1073741823
+
+print hex(31)                           # 0x1f
+print oct(31)                           # 037