2 files changed, 61 insertions, 1 deletions
diff --git a/prolog/problems/algol/algol_if_3/common.py b/prolog/problems/algol/algol_if_3/common.py
index 9198831..7e27430 100644
--- a/prolog/problems/algol/algol_if_3/common.py
+++ b/prolog/problems/algol/algol_if_3/common.py
@@ -1,3 +1,10 @@
+from operator import itemgetter
+import socket
+
+import prolog.engine
+import prolog.util
+from server.hints import Hint, HintPopup
+
 id = 177
 number = 20
 visible = True
@@ -170,5 +177,38 @@ eval(E1 * E2, State, Val) :- !,
 eval(E1 / E2, State, Val) :- !,
     eval(E1, State, V1),
     eval(E2, State, V2),
-    Val is V1 /  V2.
+    Val is V1 / V2.
 '''
+
+test_cases = [
+    ('findall(W, (W = [_], algol_if(_, W, [])), Words), Words == []',
+        [{}]),
+    ('algol_if(F, [begin,if,a,<,0,then,a,:=,0-a,else,a,:=,a,end,end], []), \
+                  apply([a= -2], Out, F), msort(Out, OutSorted), \
+                  OutSorted == [a=2,printout=[]]',
+        [{}]),
+    ('algol_if(F, [begin,if,0,<,a,then,print(a),else,b,:=,a+5,print(b),end,end], []), \
+                  apply([a= -2,b=0], Out, F), msort(Out, OutSorted), \
+		          OutSorted == [a= -2,b=3,printout=[3]]',
+        [{}]),
+]
+
+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
+
diff --git a/prolog/problems/algol/algol_if_3/sl.py b/prolog/problems/algol/algol_if_3/sl.py
new file mode 100644
index 0000000..a75bcef
--- /dev/null
+++ b/prolog/problems/algol/algol_if_3/sl.py
@@ -0,0 +1,20 @@
+name = 'algol_if/3'
+slug = 'interpreter za mini-algol z if stavkom'
+
+description = '''\
+<p>Razširi podano gramatiko za jezik mini-algol, da bo le-ta podprla uporabo stavka "if-then-else".
+Privzemi, da morata obe veji (then in else) biti prisotni v stavku. Primer:</p>
+<pre>
+% if a < b then
+%   print(a)
+% else
+%   print(b)
+% end
+?- _Program = [begin,if,a,<,b,then,print(a),else,print(b),end,end],
+    algol_if(_F, _Program, []),
+    apply([a=3,b=5], Output, _F).
+  Output = [a=3,b=5,printout=[3]].
+</pre>
+'''
+
+hint = {}