graph_drawing/tests/test_line.py

import unittest

from node import Node as N, Leaf as L
from line import generate_line, is_id, is_int


class TestLine(unittest.TestCase):

    def test_empty(self):
        self.assertEquals(generate_line(None), '<empty expression>')

    def test_simple(self):
        l0, l1 = L(1), L(2)
        plus = N('+', l0, l1)
        self.assertEquals(generate_line(plus), '1 + 2')

    def test_parentheses(self):
        l0, l1 = L(1), L(2)
        plus = N('+', l0, l1)
        times = N('*', plus, plus)
        self.assertEquals(generate_line(times), '(1 + 2)(1 + 2)')

    def test_parentheses_equal_precedence_right(self):
        l0, l1, l2 = L(1), L(2), L(3)
        plus = N('+', l1, l2)
        minus = N('-', l0, plus)
        self.assertEquals(generate_line(minus), '1 - (2 + 3)')

    def test_parentheses_equal_precedence_left(self):
        a, b, c, d = L('a'), L('b'), L('c'), L('d')
        exp = N('*', N('/', N('*', a, b), c), d)
        self.assertEquals(generate_line(exp), 'ab / c * d')

    def test_parentheses_nary(self):
        l0, l1, l2 = L(1), L(2), L(3)
        plus = N('+', N('+', l0, l1), l2)
        self.assertEquals(generate_line(plus), '1 + 2 + 3')

    def test_function(self):
        exp = L('x')
        inf = L('oo')
        minus_inf = -L('oo')
        integral = N('int', exp, minus_inf, inf)
        self.assertEquals(generate_line(integral), 'int(x, -oo, oo)')

    def test_mod(self):
        l0, l1 = L(1), L(2)
        mod = N('mod', l1, l0)
        self.assertEquals(generate_line(mod), '2 mod 1')

    def test_multiplication_identifiers(self):
        a, b = L('a'), L('b')
        self.assertEquals(generate_line(N('*', a, b)), 'ab')
        self.assertEquals(generate_line(N('*', a, -b)), 'a * -b')

    def test_multiplication_constant_identifier(self):
        l0, a = L(2), L('a')
        mul = N('*', l0, a)
        self.assertEquals(generate_line(mul), '2a')

    def test_multiplication_identifier_constant(self):
        l0, a = L(2), L('a')
        mul = N('*', a, l0)
        self.assertEquals(generate_line(mul), 'a * 2')

    def test_multiplication_constants(self):
        l0, l1 = L(1), L(2)
        mul = N('*', l0, l1)
        self.assertEquals(generate_line(mul), '1 * 2')

    def test_nary(self):
        l0, l1, l2 = L(1), L(2), L(3)
        plus = N('+', l0, l1, l2)
        self.assertEquals(generate_line(plus), '1 + 2 + 3')

    def test_pow_basic(self):
        a, b, c = L('a'), L('b'), L('c')
        node_pow = N('^', a, N('+', b, c))
        self.assertEquals(generate_line(node_pow), 'a ^ (b + c)')

    def test_pow_intermediate1(self):
        # expression: (a(b+c))^(d+e)
        a, b, c, d, e = L('a'), L('b'), L('c'), L('d'), L('e')
        node_bc = N('+', b, c)
        node_de = N('+', d, e)
        node_mul = N('*', a, node_bc)
        node_pow = N('^', node_mul, node_de)
        self.assertEquals(generate_line(node_pow), '(a(b + c)) ^ (d + e)')

    def test_pow_intermediate2(self):
        # expression: a(b+c)^(d+e)
        a, b, c, d, e = L('a'), L('b'), L('c'), L('d'), L('e')
        node_bc = N('+', b, c)
        node_de = N('+', d, e)
        node_pow = N('^', node_bc, node_de)
        node_mul = N('*', a, node_pow)
        self.assertEquals(generate_line(node_mul), 'a(b + c) ^ (d + e)')

    def test_multiplication_sign(self):
        a, b, c, l2 = L('a'), L('b'), L('c'), L(2)
        mul = N('*', a, b)
        self.assertEquals(generate_line(mul), 'ab')
        mul = N('*', mul, c)
        self.assertEquals(generate_line(mul), 'abc')
        mul = N('*', N('*', a, l2), b)
        self.assertEquals(generate_line(mul), 'a * 2b')

        plus = N('*', N('*', -a, b), c)
        self.assertEquals(generate_line(plus), '-abc')

        mul = N('*', a, N('-', b, c))
        self.assertEquals(generate_line(mul), 'a(b - c)')
        mul = N('*', l2, N('-', b, c))
        self.assertEquals(generate_line(mul), '2(b - c)')

        mul = N('*', N('+', a, b), c)
        self.assertEquals(generate_line(mul), '(a + b)c')
        mul = N('*', N('+', a, b), l2)
        self.assertEquals(generate_line(mul), '(a + b) * 2')

        mul = N('*', N('+', a, b), N('+', c, l2))
        self.assertEquals(generate_line(mul), '(a + b)(c + 2)')

        mul = N('*', l2, a)
        self.assertEquals(generate_line(mul), '2a')
        mul = N('*', a, l2)
        self.assertEquals(generate_line(mul), 'a * 2')

    def test_plus_to_minus(self):
        plus = N('+', L(1), -L(2))
        self.assertEquals(generate_line(plus), '1 - 2')

        l1, a, b, c = L(1), L('a'), L('b'), L('c')
        plus = N('+', l1, N('*', N('*', -a, b), c))
        self.assertEquals(generate_line(plus), '1 - abc')

    def test_helper_functions(self):
        l1, a = L(1), L('a')
        neg = -l1
        neg_a = -a
        plus = N('+', l1, a)

        self.assertTrue(is_id(a))
        self.assertTrue(is_id(neg_a))
        self.assertFalse(is_id(neg))
        self.assertFalse(is_id(plus))

        self.assertTrue(is_int(l1))
        self.assertTrue(is_int(neg))
        self.assertFalse(is_int(neg_a))
        self.assertFalse(is_int(plus))

    def test_negated_operator(self):
        neg = -N('+', L(1), L(2))
        self.assertEquals(generate_line(neg), '-(1 + 2)')

        neg = -N('-', L(1), L(2))
        self.assertEquals(generate_line(neg), '-(1 - 2)')

        neg = N('+', L(1), -N('+', L(1), L(2)))
        self.assertEquals(generate_line(neg), '1 - (1 + 2)')

        neg = -N('*', L(4), L('a'))
        self.assertEquals(generate_line(neg), '-4a')

        neg = -N('*', L(4), L(5))
        self.assertEquals(generate_line(neg), '-4 * 5')

        plus = N('+', L(1), -N('*', L(4), L(5)))
        self.assertEquals(generate_line(plus), '1 - 4 * 5')

        plus = N('+', L(1), -L(4))
        self.assertEquals(generate_line(plus), '1 - 4')

    def test_double_negation(self):
        neg = --L(1)
        self.assertEquals(generate_line(neg), '--1')