def make_mgr_parser(input_file, initial_states, output_file):
"""Creates a parser from a .mgr grammar file."""
print("=====", input_file, "->", output_file, "=====")
grammar = mgr.read.read_grammar(input_file, initial_states)
type = grammar.properties.get('type')
if type == 'LL':
output = makell.make_ll_parser(grammar)
elif type == 'LR':
output = makelr.make_lr_parser(grammar)
elif type:
raise Exception('File %r specifies unknown "type"' % input_file)
else:
raise Exception('File %r does not specify "type"' % input_file)
with open(output_file, 'w') as f:
f.write(output)
def make_mgr_parser(input_file, initial_states, output_file):
"""Creates a parser from a .mgr grammar file."""
print("=====", input_file, "->", output_file, "=====")
grammar = mgr.read.read_grammar(input_file, initial_states)
type = grammar.properties.get('type')
if type == 'LL':
output = makell.make_ll_parser(grammar)
elif type == 'LR':
output = makelr.make_lr_parser(grammar)
elif type:
raise Exception('File %r specifies unknown "type"' % input_file)
else:
raise Exception('File %r does not specify "type"' % input_file)
with open(output_file, 'w') as f:
f.write(output)
from grammar import Grammar
from makell import make_ll_parser
preface = "from toycalc.lex import tokenizer"
rules = {
# stat -> HELLO | IF cond THEN stat optional_else
"stat": [(("HELLO",), "lambda ctx, a: 'hello'"),
(("IF", "cond", "THEN", "stat", "optional_else"),
"lambda ctx, a, b, c, d, e: ('if', b, d, e)")],
# cond -> TRUE | FALSE
"cond": [(("TRUE",), "lambda ctx, a: True"),
(("FALSE",), "lambda ctx, a: False")],
# optional_else -> ELSE stat | epsilon
"optional_else": [(("ELSE", "stat"), "lambda ctx, a, b: b"),
((), "lambda ctx: None")],
}
properties = {
"default_start": "stat",
"llconflicts": {
("optional_else", "ELSE"): ("ELSE", "stat"),
},
}
my_grammar = Grammar(preface, properties, rules)
print(make_ll_parser(my_grammar))
