Merge branch 'master' of ssh://192.168.15.97/codeq-problems

3 files changed, 44 insertions, 0 deletions

diff --git a/prolog/common.py b/prolog/common.py
index 8e3d91d..e591e0b 100644
--- a/prolog/common.py
+++ b/prolog/common.py
@@ -1,4 +1,6 @@
 import operator
+import socket
+
 import prolog.engine
 from prolog.util import tokenize
 from server.hints import Hint, HintPopup
@@ -22,6 +24,7 @@ hint_type = {
 
 # Check program for syntax errors.
 def check_syntax(code, aux_code):
+    engine_id = None
     try:
         engine_id, output = prolog.engine.create(code=code+aux_code, timeout=1.0)
         if 'error' in map(operator.itemgetter(0), output):
diff --git a/prolog/problems/lists_advanced/rev_2/common.py b/prolog/problems/lists_advanced/rev_2/common.py
index b673660..f79ddca 100644
--- a/prolog/problems/lists_advanced/rev_2/common.py
+++ b/prolog/problems/lists_advanced/rev_2/common.py
@@ -39,6 +39,10 @@ hint_type = {
 test_cases = [
     ('rev([], X)',
         [{'X': '[]'}]),
+    ('rev(X, [])',
+        [{'X': '[]'}]),
+    ('rev([42], X)',
+        [{'X': '[42]'}]),
     ('rev([s, k, c, d, d], X)',
         [{'X': '[d, d, c, k, s]'}]),
     ('rev(X, [s, k, c, d, d])',
diff --git a/readme.md b/readme.md
index da79939..7f9fbc0 100644
--- a/readme.md
+++ b/readme.md
@@ -217,3 +217,40 @@ Problem files
     razdalja = v ** 2 * sin(2 * kot_rad) / g
     print("Kroglo bo odneslo", razdalja, "metrov.")
     '''
+
+
+Style
+=====
+
+Please observe the following stylistic rules when adding or translating
+problems.
+
+  * Wrap lines at 80 columns (not a hard rule).
+
+Special characters
+------------------
+
+Use appropriate Unicode characters wherever possible. If your setup makes it
+difficult to enter these characters, copy them from this file.
+
+  * "foo" →  “foo” (english) or „foo“ (slovene)
+  * '     →  ’ (typographic apostrophe)
+  * ...   →  … (ellipsis)
+  * 2x3   →  2×3 (multiplication sign)
+  * <=    →  ≤
+  * >=    →  ≥
+  * ->    →  →
+  * =>    →  ⇒
+  * --    →  – (en dash)
+  * :)    →  ☺
+  * ;)    →  😉
+
+Some other useful characters:
+
+  * ∪ (set union)
+  * ∩ (set intersection)
+  * ∖ (set difference)
+  * ⊂
+  * ⊆
+  * ⊃
+  * ⊇