def test_parse_unit(self):
"""Tests to check whether the following production rule is implemented
correctly:
<unit> ::= <identifier> | <number> | '(' <expr> ')' |
<function> '(' <expr> ')'
The parse tree for 'sqrt(a*2)' should be built as follows:
{sqrt}
|
{*}
/ |
{a} {2}
"""
root_node = expression_parser.Parser().parse('sqrt(a*2)')
# Root node {sqrt}.
self.assertIsInstance(root_node, expression_parser.UnaryFunctionNode)
self.assertEqual(len(root_node.children), 1)
child_1 = root_node.children[0]
# Child 1 {*}.
self.assertIsInstance(
child_1, expression_parser.MultiplicationOperatorNode)
self.assertEqual(len(child_1.children), 2)
left_child_2, right_child_2 = child_1.children
# Left child 2 {a}.
self.assertIsInstance(left_child_2, expression_parser.IdentifierNode)
self.assertEqual(left_child_2.token.text, 'a')
self.assertEqual(len(left_child_2.children), 0)
# Right child 2 {2}.
self.assertIsInstance(right_child_2, expression_parser.NumberNode)
self.assertEqual(right_child_2.token.text, '2')
self.assertEqual(len(right_child_2.children), 0)
def test_parse_mul_expr(self):
"""Tests to check whether the following production rule is implemented
correctly:
<mul_expr> ::= <pow_expr> (('*' | '/') <pow_expr>)*
The parse tree for 'a / b * 2' should be built as follows:
{*}
/ |
{/} {2}
/ |
{a} {b}
"""
root_node = expression_parser.Parser().parse('a / b * 2')
# Root node {*}.
self.assertIsInstance(
root_node, expression_parser.MultiplicationOperatorNode)
self.assertEqual(len(root_node.children), 2)
left_child_1, right_child_1 = root_node.children
# Left child 1 {/}.
self.assertIsInstance(
left_child_1, expression_parser.DivisionOperatorNode)
self.assertEqual(len(left_child_1.children), 2)
# Right child 1 {2}.
self.assertIsInstance(right_child_1, expression_parser.NumberNode)
self.assertEqual(right_child_1.token.text, '2')
self.assertEqual(len(right_child_1.children), 0)
left_child_2, right_child_2 = left_child_1.children
# Left child 2 {a}.
self.assertIsInstance(left_child_2, expression_parser.IdentifierNode)
self.assertEqual(left_child_2.token.text, 'a')
self.assertEqual(len(left_child_2.children), 0)
# Right child 2 {b}.
self.assertIsInstance(right_child_2, expression_parser.IdentifierNode)
self.assertEqual(right_child_2.token.text, 'b')
self.assertEqual(len(right_child_2.children), 0)
def test_parse_pow_expr(self):
"""Tests to check whether the following production rule is implemented
correctly:
<pow_expr> ::= '-' <pow_expr> | '+' <pow_expr> |
<unit> ('^' <pow_expr>)?
The parse tree for 'a ^ b ^ 2' should be built as follows:
{^}
/ |
{a} {^}
/ |
{b} {2}
"""
root_node = expression_parser.Parser().parse('a ^ b ^ 2')
# Root node {^}.
self.assertIsInstance(root_node, expression_parser.PowerOperatorNode)
self.assertEqual(len(root_node.children), 2)
left_child_1, right_child_1 = root_node.children
# Left child 1 {a}.
self.assertIsInstance(left_child_1, expression_parser.IdentifierNode)
self.assertEqual(left_child_1.token.text, 'a')
self.assertEqual(len(left_child_1.children), 0)
# Right child 1 {^}.
self.assertIsInstance(
right_child_1, expression_parser.PowerOperatorNode)
self.assertEqual(len(right_child_1.children), 2)
left_child_2, right_child_2 = right_child_1.children
# Left child 2 {b}.
self.assertIsInstance(left_child_2, expression_parser.IdentifierNode)
self.assertEqual(left_child_2.token.text, 'b')
self.assertEqual(len(left_child_2.children), 0)
# Right child 2 {2}.
self.assertIsInstance(right_child_2, expression_parser.NumberNode)
self.assertEqual(right_child_2.token.text, '2')
self.assertEqual(len(right_child_2.children), 0)
def test_parse(self):
"""Tests to check whether the following production rule is implemented
correctly:
<expr> ::= <mul_expr> (('+' | '-') <mul_expr>)*
The parse tree for 'a + b - 2' should be built as follows:
{-}
/ |
{+} {2}
/ |
{a} {b}
"""
root_node = expression_parser.Parser().parse('a + b - 2')
# Root node {-}.
self.assertIsInstance(
root_node, expression_parser.SubtractionOperatorNode)
self.assertEqual(len(root_node.children), 2)
left_child_1, right_child_1 = root_node.children
# Left child 1 {+}.
self.assertIsInstance(
left_child_1, expression_parser.AdditionOperatorNode)
self.assertEqual(len(left_child_1.children), 2)
# Right child 1 {2}.
self.assertIsInstance(right_child_1, expression_parser.NumberNode)
self.assertEqual(right_child_1.token.text, '2')
self.assertEqual(len(right_child_1.children), 0)
left_child_2, right_child_2 = left_child_1.children
# Left child 2 {a}.
self.assertIsInstance(left_child_2, expression_parser.IdentifierNode)
self.assertEqual(left_child_2.token.text, 'a')
self.assertEqual(len(left_child_2.children), 0)
# Right child 2 {b}.
self.assertIsInstance(right_child_2, expression_parser.IdentifierNode)
self.assertEqual(right_child_2.token.text, 'b')
self.assertEqual(len(right_child_2.children), 0)
