--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.hgignore	Sat May 25 23:24:10 2019 +0200
@@ -0,0 +1,4 @@
+htmlcov/*
+__pycache__/
+.pytest_cache/
+.coverage

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pcombinators/tests/test_arith.py	Sat May 25 23:24:10 2019 +0200
@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Created on Sat May 25 22:09:49 2019
+
+@author: lbo
+"""
+
+import io
+import unittest
+
+import pcombinators.state as st
+import pcombinators.tests.arith as arith
+
+class TestArith(unittest.TestCase):
+
+    def test_simple_addition(self):
+        want = (1., '+', 2.)
+        got = arith.parse('1 + 2')
+        self.assertEqual(got, want)
+
+    def test_simple_multiplication(self):
+        want = ('a', '*', 'b')
+        got = arith.parse('a* b')
+        self.assertEqual(got, want)
+
+    def test_parens(self):
+        want = ('a', '^', (3., '-', 'e'))
+        got = arith.parse('a ^ ( 3 - e)')
+        self.assertEqual(got, want)
+
+    def test_var(self):
+        want = ('a')
+        self.assertEqual(arith.parse('a'), want)
+
+    def test_float(self):
+        want = (1.23456789, '+', (-123.456, '*', 332.))
+        got = arith.parse('1.23456789+-123.456*332')
+        self.assertEqual(got, want)
+
+    def test_fails(self):
+        self.assertIsNone(arith.parse('1 + (a +)'))
+        self.assertIsNone(arith.parse('1 +'))
+        self.assertIsNone(arith.parse('1 *'))
+        self.assertIsNone(arith.parse('1 -'))
+
+    def test_complicated(self):
+        complicated_haves = [
+                '1 + 1', # easy for a start
+                '3*4*(a - (b - (c - d) ) * 4)^a^c',
+                'a^b^c+d^e^f',
+                'a*b+c/d',
+                'a + b^(c - d/e) * (3 - (4 + a) + 6^-1)',
+        ]
+        complicated_wants = [
+                (1, '+', 1),
+                (3.0,  '*',
+                 (4.0, '*',
+                  (('a', '-',
+                    (('b', '-', ('c', '-', 'd')), '*', 4.0)
+                   ), '^',
+                    ('a', '^', 'c')))),
+                (('a', '^', ('b', '^', 'c')), '+', ('d', '^', ('e', '^', 'f'))),
+                (('a','*','b'),'+',('c','/','d')),
+                ('a','+',(('b', '^', ('c', '-', ('d', '/', 'e'))), '*',(3.0, '-', ((4.0, '+', 'a'), '+', (6.0, '^', -1.0)))))
+        ]
+        for (i, (h, w)) in enumerate(zip(complicated_haves, complicated_wants)):
+            self.assertEqual(arith.parse(h), w)
+        # Assert that this parser also works with the ParseFileState class.
+        for (i, (h, w)) in enumerate(zip(complicated_haves, complicated_wants)):
+            h = h.replace(' ', '')
+            self.assertEqual(arith.parse(st.ParseFileState(io.StringIO(h))), w)
+
+if __name__ == '__main__':
+    st.ParseFileState.COLLECT_LOWER_LIMIT = 0
+    unittest.main()
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test.sh	Sat May 25 23:24:10 2019 +0200
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+export PYTHONPATH=.
+
+python3 -m pcombinators.tests.test_arith
+coverage run -m pcombinators.tests.test_arith
+coverage html