1 files changed, 43 insertions, 0 deletions
diff --git a/yaksh/compare_stdio.py b/yaksh/compare_stdio.py
new file mode 100644
index 0000000..c4076de
--- /dev/null
+++ b/yaksh/compare_stdio.py
@@ -0,0 +1,43 @@
+try:
+    from itertools import zip_longest
+except ImportError:
+    from itertools import izip_longest as zip_longest
+
+    
+def _get_incorrect_user_lines(exp_lines, user_lines):
+    err_line_numbers = []
+    for line_no, (expected_line, user_line) in \
+     enumerate(zip_longest(exp_lines, user_lines)):
+        if not user_line or not expected_line or \
+         user_line.strip() != expected_line.strip():
+            err_line_numbers.append(line_no)
+    return err_line_numbers
+    
+def compare_outputs(expected_output, user_output, given_input=None):
+    given_lines = user_output.splitlines()
+    exp_lines = expected_output.splitlines()
+    msg = {"given_input":given_input,
+           "expected_output": exp_lines,
+           "user_output":given_lines
+            }
+    ng = len(given_lines)
+    ne = len(exp_lines)
+    err_line_numbers = _get_incorrect_user_lines(exp_lines, given_lines)
+    msg["error_line_numbers"] = err_line_numbers
+    if ng != ne:
+        msg["error_msg"] = ("Incorrect Answer: "
+                            + "We had expected {} number of lines. ".format(ne)
+                            + "We got {} number of lines.".format(ng)
+                            )
+        return False, msg
+    else:
+        if err_line_numbers:
+            msg["error_msg"] = ("Incorrect Answer: "
+                             + "Line number(s) {0} did not match."
+                                .format(", ".join(map(
+                                  str,[x+1 for x in err_line_numbers]
+                                ))))
+            return False, msg
+        else:
+            msg["error_msg"] = "Correct Answer"
+            return True, msg