1 files changed, 133 insertions, 0 deletions
diff --git a/l6/kod.py b/l6/kod.py
new file mode 100644
index 0000000..060dc21
--- /dev/null
+++ b/l6/kod.py
@@ -0,0 +1,133 @@
+import sys
+
+import calc
+
+def debug(tag, msg):
+    #print("[{}] {}".format(tag, msg))
+    pass
+
+def eval_binary(frame, statement):
+    debug("BINARY", statement)
+    op = calc.condition_operator(statement)
+    if op == "+":
+        return eval_expression(frame, calc.condition_left(statement)) \
+            + eval_expression(frame, calc.condition_right(statement))
+    elif op == "-":
+        return eval_expression(frame, calc.condition_left(statement)) \
+            - eval_expression(frame, calc.condition_right(statement))
+    elif op == "*":
+        return eval_expression(frame, calc.condition_left(statement)) \
+            * eval_expression(frame, calc.condition_right(statement))
+    elif op == "/":
+        return eval_expression(frame, calc.condition_left(statement)) \
+            / eval_expression(frame, calc.condition_right(statement))
+
+def eval_expression(frame, statement):
+    debug("EXPRESSION", statement)
+    if calc.isconstant(statement):
+        if not (type(statement) is int or type(statement) is float):
+            print("{} is not a valid constant, need to be either int or float"
+                  .format(statement))
+            sys.exit(-1)
+        return statement
+    elif calc.isvariable(statement):
+        if statement not in frame:
+            print("variable {} not declared", statement)
+            sys.exit(-1)
+        return frame[statement]
+    elif calc.isbinary(statement):
+        return eval_binary(frame, statement)
+    else:
+        print("{} is not valid syntax".format(statement))
+        sys.exit(-1)
+
+def eval_assignment(frame, statement):
+    debug("ASSIGNMENT", statement)
+    new_frame = frame.copy()
+    new_frame[calc.assignment_variable(statement)] = \
+        eval_expression(frame, calc.assignment_expression(statement))
+    return new_frame
+
+def eval_condition(frame, statement):
+    debug("CONDITION", statement)
+    op = calc.condition_operator(statement)
+    if op == ">":
+        return eval_expression(frame, calc.condition_left(statement)) \
+            > eval_expression(frame, calc.condition_right(statement))
+    elif op == "<":
+        return eval_expression(frame, calc.condition_left(statement)) \
+            < eval_expression(frame, calc.condition_right(statement))
+    elif op == "=":
+        return eval_expression(frame, calc.condition_left(statement)) \
+            == eval_expression(frame, calc.condition_right(statement))
+    else:
+        print("{} is not valid syntax".format(statement))
+        sys.exit(-1)
+
+def eval_repetition(frame, statement):
+    debug("REPETITION", statement)
+    new_frame = frame.copy()
+    while eval_condition(new_frame, calc.repetition_condition(statement)):
+        new_frame = eval_statements(new_frame, calc.repetition_statements(statement))
+    return new_frame
+
+def eval_selection(frame, statement):
+    debug("SELECTION", statement)
+    new_frame = frame.copy()
+    if eval_condition(frame, calc.selection_condition):
+        new_frame = eval_statement(frame, calc.selection_true(statement))
+    elif calc.hasfalse(statement):
+        new_frame = eval_statement(frame, calc.selection_false(statement))
+    return new_frame
+
+def eval_input(frame, statement):
+    debug("INPUT", statement)
+    new_frame = frame.copy()
+    var = calc.input_variable(statement)
+    val = input("Enter value for {}: ".format(var))
+    try:
+        new_frame[var] = int(val)
+    except ValueError:
+        try:
+            new_frame[var] = float(val)
+        except ValueError:
+            pass  #TODO
+    return new_frame
+
+def eval_output(frame, statement):
+    debug("OUTPUT", statement)
+    var = calc.output_variable(statement)
+    val = frame[var]
+    print("{} = {}".format(var, val))
+
+def eval_statement(frame, statement):
+    debug("STATEMENT", statement)
+    new_frame = frame.copy()
+    if calc.isassignment(statement):
+        new_frame = eval_assignment(frame, statement)
+    elif calc.isrepetition(statement):
+        new_frame = eval_repetition(frame, statement)
+    elif calc.isselection(statement):
+        new_frame = eval_selection(frame, statement)
+    elif calc.isinput(statement):
+        new_frame = eval_input(frame, statement)
+    elif calc.isoutput(statement):
+        eval_output(frame, statement)
+    else:
+        print("{} is not valid syntax".format(statement))
+        sys.exit(-1)
+    return new_frame
+
+def eval_statements(frame, statements):
+    debug("STATEMENTS", statements)
+    new_frame = eval_statement(frame, calc.first_statement(statements))
+    if calc.empty_statements(calc.rest_statements(statements)):
+        return new_frame
+    else:
+        return eval_statements(new_frame, calc.rest_statements(statements))
+
+def eval_program(program):
+    if not calc.isprogram(program):
+        return
+    statements = calc.program_statements(program)
+    return eval_statements({}, statements)