def test_follow2(self):
expected = {'S': set('$'), 'A': set('$'), 'B': set('b'), 'C': set('d')}
g = grammar.make_dummy_grammar("test_input/test2.cfg")
first = first_follow.get_first(g)
got = first_follow.get_follow(g, first)
self.assertEqual(expected, got)
def construct_parse_table(g):
first = first_follow.get_first(g)
follow = first_follow.get_follow(g, first)
# len(term) columns, since we also need a column for $ but not one for ""
parse_table = [[None for j in range(len(g.term))]
for i in range(len(g.nonterm))]
# for rule A -> a (a could be string of terms/nonterms)
for rule in g.rules:
row = g.nonterm.index(rule.lhs)
first_set = []
for idx, sym in enumerate(rule.rhs):
if len(first_set) == 0:
first_set.extend(first[sym])
else:
if "" in first[rule.rhs[idx - 1]]:
first_set.extend(first[sym])
# For each term t in First(a) add A->a to M[A,t] (only if t != "")
for term in first_set:
col = g.term.index(term)
if term != "":
parse_table[row][col] = rule
# If "" in First(a), for each terminal b in Follow(A),
# add A->a to M[A,b]
else:
follow_set = follow[rule.lhs]
for sym in follow_set:
if sym == "$":
col = -1
else:
col = g.term.index(sym)
parse_table[row][col] = rule
return parse_table
def test_follow1(self):
expected = {'A': set('$'), 'D': set(['$', 'e']), 'E': set("$")}
g = grammar.make_dummy_grammar("test_input/test1.cfg")
first = first_follow.get_first(g)
got = first_follow.get_follow(g, first)
self.assertEqual(expected, got)
def main(fname):
with open(fname, "r") as infile:
tokens = scanner.scan(infile, rules)
tokens.append(scanner.Symbol("$", "EOF", -1, -1, -1))
#print(tokens)
g = grammar.Grammar(grammar_dict)
lr_parse_common.augment_grammar(g)
for rule in g.rules:
if rule.to_node is None:
rule.to_node = lambda rule, children: ast.ASTNode(
rule.lhs, children)
kernel = slr1.LR0Item(g.rules[-1], 0)
first_set = first_follow.get_first(g)
follow = first_follow.get_follow(g, first_set)
dfa = lr_parse_common.make_dfa(g, slr1.closure, kernel, first_set)
action, goto_table = slr1.make_parse_table(dfa, follow, g)
ast_root = lr_parse_common.parse(dfa, action, goto_table, tokens, g)
print(ast.gen_ast_digraph(ast_root))
gen_code = gen_ir.CodeGenVisitor(ast_root)
gen_code.accept()
with open(fname + ".ll", "w") as outfile:
outfile.write(gen_code.get_code())
def test_not_slr1_grammar(self):
g = grammar.make_dummy_grammar("test_input/test4.cfg")
lr_parse_common.augment_grammar(g)
first = first_follow.get_first(g)
follow = first_follow.get_follow(g, first)
kernel = slr1.LR0Item(g.rules[-1], 0)
dfa = lr_parse_common.make_dfa(g, slr1.closure, kernel, first)
with self.assertRaises(lr_parse_common.ShiftReduceError):
action, goto_table = slr1.make_parse_table(dfa, follow, g)
def main():
import scanner
g = grammar.make_dummy_grammar("test_input/test4.cfg")
lr_parse_common.augment_grammar(g)
kernel = LR1Item(g.rules[-1], 0, "$")
first_set = first_follow.get_first(g)
follow = first_follow.get_follow(g, first_set)
dfa = lr_parse_common.make_dfa(g, closure, kernel, first_set)
print(dfa.generate_dot_file())
action, goto = make_parse_table(dfa, follow, g)
tokens = scanner.dummy_tokenize("i=*i$")
ast_root = lr_parse_common.parse(dfa, action, goto, tokens, g)
print(ast.gen_ast_digraph(ast_root))
def main():
import scanner
g = grammar.make_dummy_grammar("test_input/test3.cfg")
lr_parse_common.augment_grammar(g)
first = first_follow.get_first(g)
follow = first_follow.get_follow(g, first)
# the kernel is the new rule just added (by augmenting) with the dist marker at the beginning
kernel = LR0Item(g.rules[-1], 0)
dfa = lr_parse_common.make_dfa(g, closure, kernel, first)
print(dfa.generate_dot_file())
action, goto_table = make_parse_table(dfa, follow, g)
print(action)
print(goto_table)
tokens = scanner.dummy_tokenize("(a(a((a))))$")
ast_root = lr_parse_common.parse(dfa, action, goto_table, tokens, g)
print(ast.gen_ast_digraph(ast_root))
def test_make_table(self):
g = grammar.make_dummy_grammar("test_input/test3.cfg")
lr_parse_common.augment_grammar(g)
first = first_follow.get_first(g)
follow = first_follow.get_follow(g, first)
kernel = slr1.LR0Item(g.rules[-1], 0)
dfa = lr_parse_common.make_dfa(g, slr1.closure, kernel, first)
action, goto_table = slr1.make_parse_table(dfa, follow, g)
expected_action = [
['s3', 's4', None, None],
[None, None, None, 'accept'],
[None, None, None, 'r0'],
['r2', 'r2', 'r2', 'r2'],
['s3', 's4', None, None],
['s3', 's4', 'r4', None],
[None, None, 's8', None],
[None, None, 'r3', None],
['r1', 'r1', 'r1', 'r1']
]
self.assertEqual(expected_action, action)
expected_goto = [
[1, 2, None, None],
[None, None, None, None],
[None, None, None, None],
[None, None, None, None],
[None, 5, 6, None],
[None, 5, 7, None],
[None, None, None, None],
[None, None, None, None],
[None, None, None, None]
]
self.assertEqual(expected_goto, goto_table)