def test_given_tree_then_correct_squash(self) -> None:
from cmaj.testing.ast import tree, token
node = tree(('X', [('X', [token('Y', 0),
('X', [token('Y', 1),
token('X', 2)])]),
('Y', [('X', [token('X', 3)])])]))
result = squash(node, 'X')
expected = tree(('X', [token('Y', 0), token('Y', 1), token('X', 2), ('Y', [token('X', 3)])]))
self.assertEqual(expected, result)
def compile_grammar(grammar_node: Node) -> Grammar:
from cmaj.ast.simplify import squash, prune, skip
grammar_node = squash(grammar_node, 'GRAMMAR', 'OPTION', 'SEQUENCE')
grammar_node = prune(grammar_node, 'comment', '=', '|', 'eol')
grammar_node = skip(grammar_node, 'LINE', 'ANCHOR')
rules: List[Rule] = []
for definition_node in grammar_node.children:
identifier, option = definition_node.children
rules += compile_rules(identifier.token.value, option)
return Grammar(*rules)
def test_given_root_is_leaf_then_no_squash(self) -> None:
from cmaj.testing.ast import tree
tree_def = ('node', [])
result = squash(tree(tree_def), 'node')
self.assertEqual(tree(tree_def), result)
def test_given_nodes_to_squash_separated_by_other_node_then_no_squash(self) -> None:
from cmaj.testing.ast import tree, token
tree_def = ('X', [('Y', [token('X', 0)])])
result = squash(tree(tree_def), 'X')
self.assertEqual(tree(tree_def), result)
def test_given_chain_then_squash_to_single_node(self) -> None:
from cmaj.testing.ast import tree, token
node = tree(('Y', [('X', [('X', [('X', [token('Y', 0)])])])]))
result = squash(node, 'X')
expected = tree(('Y', [('X', [token('Y', 0)])]))
self.assertEqual(expected, result)
def test_given_inner_node_to_squash_then_grandchildren_become_children(self) -> None:
from cmaj.testing.ast import tree, token
node = tree(('Y', [('X', [('X', [token('Y', 0), token('Y', 1)])])]))
result = squash(node, 'X')
expected = tree(('Y', [('X', [token('Y', 0), token('Y', 1)])]))
self.assertEqual(expected, result)
def test_given_many_children_to_squash_when_parent_is_root_then_no_squash(self) -> None:
from cmaj.testing.ast import tree, token
tree_def = ('X', [token('X', 0), token('X', 1)])
result = squash(tree(tree_def), 'X')
self.assertEqual(tree(tree_def), result)
def test_given_single_child_to_squash_when_parent_is_root_then_child_becomes_root(self) -> None:
from cmaj.testing.ast import tree, token
node = tree(('X', [token('X', 0)]))
result = squash(node, 'X')
expected = tree(token('X', 0))
self.assertEqual(expected, result)