3 files changed, 76 insertions, 0 deletions
diff --git a/prolog/problems/lists_advanced/shiftleft_2/common.py b/prolog/problems/lists_advanced/shiftleft_2/common.py
new file mode 100644
index 0000000..13db28f
--- /dev/null
+++ b/prolog/problems/lists_advanced/shiftleft_2/common.py
@@ -0,0 +1,50 @@
+# coding=utf-8
+
+from operator import itemgetter
+import prolog.engine
+import server.problems
+
+id = 113
+number = 20
+visible = False
+facts = None
+
+solution = '''\
+conc113([], L, L).
+conc113([H|T], L2, [H|L]) :-
+  conc113(T, L2, L).
+shiftleft([H|T], L2) :-
+  conc113(T, [H], L2).
+'''
+
+test_cases = [
+    ('shiftleft([i], X)',
+        [{'X': '[i]'}]),
+    ('shiftleft([h, e, u, l], X)',
+        [{'X': '[e, u, l, h]'}]),
+    ('shiftleft([h, A, B, l, c], [x, y, C, D, E])',
+        [{'A': 'x', 'B': 'y', 'C': 'l', 'D': 'c', 'E': 'h'}]),
+]
+
+def test(code, aux_code):
+    n_correct = 0
+    engine_id = None
+    try:
+        engine_id, output = prolog.engine.create(code=code+aux_code, timeout=1.0)
+        if engine_id is not None and 'error' not in map(itemgetter(0), output):
+            # Engine successfully created, and no syntax error in program.
+            for query, answers in test_cases:
+                if prolog.engine.check_answers(engine_id, query=query, answers=answers, timeout=1.0):
+                    n_correct += 1
+    except socket.timeout:
+        pass
+    finally:
+        if engine_id:
+            prolog.engine.destroy(engine_id)
+
+    hints = [{'id': 'test_results', 'args': {'passed': n_correct, 'total': len(test_cases)}}]
+    return n_correct, len(test_cases), hints
+
+def hint(code, aux_code):
+    # TODO
+    return []
diff --git a/prolog/problems/lists_advanced/shiftleft_2/en.py b/prolog/problems/lists_advanced/shiftleft_2/en.py
new file mode 100644
index 0000000..a8dd5f0
--- /dev/null
+++ b/prolog/problems/lists_advanced/shiftleft_2/en.py
@@ -0,0 +1,13 @@
+# coding=utf-8
+
+name = 'shiftleft/2'
+slug = 'shift a list left'
+
+description = '''\
+<p><code>shiftleft(L1, L2)</code>: the list <code>L2</code> is obtained from L1 by shifting elements to the left by one (circular shift).</p>
+<pre>
+?- shiftleft([1,2,3,4,5], X).
+  X = [2,3,4,5,1].
+</pre>'''
+
+hint = {}
diff --git a/prolog/problems/lists_advanced/shiftleft_2/sl.py b/prolog/problems/lists_advanced/shiftleft_2/sl.py
new file mode 100644
index 0000000..ae412a6
--- /dev/null
+++ b/prolog/problems/lists_advanced/shiftleft_2/sl.py
@@ -0,0 +1,13 @@
+# coding=utf-8
+
+name = 'shiftleft/2'
+slug = 'Premakni elemente seznama za eno mesto v levo'
+
+description = '''\
+<p><code>shiftleft(L1, L2)</code>: elemente v seznamu <code>L1</code> za eno mesto premaknemo v levo ("circular shift").</p>
+<pre>
+?- shiftleft([1,2,3,4,5], X).
+  X = [2,3,4,5,1].
+</pre>'''
+
+hint = {}