Create base for future parsers

This commit is contained in:
Bartłomiej Pluta
2019-07-11 18:24:05 +02:00
parent f91e2a75de
commit ed2c8dc6dd
2 changed files with 164 additions and 188 deletions

View File

@@ -1,5 +1,6 @@
from smnp.ast.node.ignore import IgnoredNode
from smnp.ast.node.model import ParseResult, Node
from smnp.ast.node.none import NoneNode
from smnp.error.syntax import SyntaxException
@@ -29,7 +30,12 @@ class Parser(object):
def grammar(self):
rules = []
self._grammarRules(rules)
return "\n".join(rules)
return "\n".join(self._uniq(rules))
def _uniq(self, seq):
seen = set()
seen_add = seen.add
return [x for x in seq if not (x in seen or seen_add(x))]
def _grammarRules(self, output):
output.append(f"class '{self.__class__.__name__}' does not implement _grammarRules() method")
@@ -44,6 +50,37 @@ class Parser(object):
return self.__str__()
class Parsers:
@staticmethod
def terminal(expectedType, createNode=lambda val, pos: IgnoredNode(pos), doAssert=False):
return TerminalParser(expectedType, createNode, doAssert)
@staticmethod
def oneOf(*parsers, name, exception=None):
return OneOfParser(*parsers, name=name, exception=exception)
@staticmethod
def allOf(*parsers, createNode, exception=None, name):
return AllOfParser(*parsers, createNode=createNode, exception=exception, name=name)
@staticmethod
def leftAssociativeOperatorParser(leftParser, operatorTokenTypes, rightParser, createNode, name):
return LeftAssociativeOperatorParser(leftParser, operatorTokenTypes, rightParser, createNode, name)
@staticmethod
def many(itemParser, createNode, name):
return ManyParser(itemParser, createNode, name)
@staticmethod
def optional(parser, name):
return OptionalParser(parser, name)
@staticmethod
def loop(startParser, itemParser, endParser, createNode, name):
return LoopParser(startParser, itemParser, endParser, createNode, name)
class TerminalParser(Parser):
def __init__(self, expectedType, createNode=lambda val, pos: IgnoredNode(pos), doAssert=False):
@@ -67,6 +104,7 @@ class TerminalParser(Parser):
return ParseResult.FAIL()
class OneOfParser(Parser):
def __init__(self, *parsers, name, exception=None):
super().__init__(name)
@@ -134,175 +172,107 @@ class AllOfParser(Parser):
output.append(self.name + ' -> ' + ' '.join([ parser.name for parser in self.parsers ]))
[ parser._grammarRules(output) for parser in self.parsers ]
# def allOf(*parsers, createNode, exception=None, name="all"):
# if len(parsers) == 0:
# raise RuntimeError("Pass one parser at least")
#
# def extendedParser(input):
# snap = input.snapshot()
#
# results = []
#
# for parser in parsers:
# result = parser(input)
#
# if not result.result:
# if exception is not None:
# if callable(exception):
# raise exception(input)
# else:
# raise exception
#
# input.reset(snap)
# return ParseResult.FAIL()
#
# results.append(result.node)
#
# node = createNode(*results)
# if not isinstance(node, Node):
# raise RuntimeError("Function 'createNode' haven't returned a Node object. Probably forget to pass 'return'")
#
# return ParseResult.OK(node)
#
#
# return Parser(extendedParser, name=name, parsers=parsers)
#
class LeftAssociativeOperatorParser(Parser):
def __init__(self, leftParser, operatorTokenTypes, rightParser, createNode, name):
from smnp.ast.node.operator import Operator
super().__init__(name)
self.leftParser = leftParser
self.rightParser = rightParser
self.createNode = createNode
self.operators = operatorTokenTypes
operatorParsers = [ TerminalParser(expectedType, createNode=lambda val, pos: Operator.withValue(val, pos)) for expectedType in operatorTokenTypes ]
self.operatorParser = OneOfParser(*operatorParsers, name="not important")
def _parse(self, input):
snap = input.snapshot()
left = self.leftParser.parse(input)
if left.result:
operator = self.operatorParser.parse(input)
while operator.result:
right = self.rightParser.parse(input)
left = ParseResult.OK(self.createNode(left.node, operator.node, right.node))
operator = self.operatorParser.parse(input)
return left
return ParseResult.FAIL()
# def o
# # a -> A
# @staticmethod
# def terminalParser(expectedType, createNode=None, doAssert=False):
# def provideNode(value, pos):
# if createNode is None:
# return IgnoredNode(pos)
# return createNode(value, pos)
#
# def parse(input):
# if input.hasCurrent() and input.current().type == expectedType:
# token = input.current()
# input.ahead()
# return ParseResult.OK(provideNode(token.value, token.pos))
# elif doAssert:
# found = f", found '{input.current().rawValue}'" if input.hasCurrent() else ""
# raise SyntaxException(f"Expected '{expectedType.key}'{found}", input.currentPos())
#
# return ParseResult.FAIL()
#
# return Parser(parse, name=expectedType.name.lower())
#
# # oneOf -> a | b | c | ...
# @staticmethod
# def oneOf(*parsers, exception=None, name="or"):
# def combinedParser(input):
# snap = input.snapshot()
# for parser in parsers:
# value = parser(input)
# if value.result:
# return value
#
# if exception is not None:
# if callable(exception):
# raise exception(input)
# else:
# raise exception
#
#
# input.reset(snap)
# return ParseResult.FAIL()
#
# return Parser(combinedParser, name=name, parsers=parsers)
#
# # allOf -> a b c ...
# @staticmethod
def _grammarRules(self, output):
output.append('\n'.join([f"{self.name} -> {self.leftParser.name} {operator.name.lower()} {self.rightParser.name} | {self.leftParser.name}" for operator in self.operators]))
self.leftParser._grammarRules(output)
self.rightParser._grammarRules(output)
class ManyParser(Parser):
def __init__(self, itemParser, createNode, name):
super().__init__(name)
self.itemParser = itemParser
self.createNode = createNode
def _parse(self, input):
snap = input.snapshot()
parsedItems = []
pos = input.currentPos()
while True:
result = self.itemParser.parse(input)
if result.result:
parsedItems.append(result.node)
snap = input.snapshot()
else:
input.reset(snap)
return ParseResult.OK(self.createNode(parsedItems, pos) if len(parsedItems) > 0 else NoneNode())
def _grammarRules(self, output):
output.append(f"{self.name} -> {self.itemParser.name}*")
self.itemParser._grammarRules(output)
class OptionalParser(Parser):
def __init__(self, parser, name):
super().__init__(name)
self.parser = parser
def _parse(self, input):
result = self.parser.parse(input)
if result.result:
return result
return ParseResult.OK(NoneNode())
def _grammarRules(self, output):
output.append(f"{self.name} -> {self.parser.name}?")
class LoopParser(Parser):
def __init__(self, startParser, itemParser, endParser, createNode, name):
super().__init__(name)
self.startParser = startParser
self.itemParser = itemParser
self.endParser = endParser
self.createNode = createNode
def _parse(self, input):
items = []
start = self.startParser.parse(input)
if start.result:
while True:
end = self.endParser.parse(input)
if end.result:
return ParseResult.OK(self.createNode(start.node, items, end.node))
item = self.itemParser.parse(input)
if not item.result:
return ParseResult.FAIL()
items.append(item.node)
return ParseResult.FAIL()
def _grammarRules(self, output):
output.append(f"{self.name} -> {self.startParser.name} {self.itemParser.name}* {self.endParser.name}")
self.startParser._grammarRules(output)
self.itemParser._grammarRules(output)
self.endParser._grammarRules(output)
#
# # leftAssociative -> left | left OP right
# @staticmethod
# def leftAssociativeOperatorParser(leftParser, operatorTokenTypes, rightParser, createNode, name="leftAssoc"):
# from smnp.ast.node.operator import Operator
#
# def parse(input):
# operatorParser = Parser.oneOfTerminals(*operatorTokenTypes, createNode=lambda val, pos: Operator.withChildren([val], pos))
# left = leftParser(input)
# if left.result:
# operator = operatorParser(input)
# while operator.result:
# right = rightParser(input)
# left = ParseResult.OK(createNode(left.node, operator.node, right.node))
# operator = operatorParser(input)
# return left
#
# return ParseResult.FAIL()
#
# return Parser(parse, name=name, parsers=[leftParser, '|'.join([t.value for t in operatorTokenTypes]), rightParser])
#
# @staticmethod
# def oneOfTerminals(*tokenTypes, createNode=None):
# return Parser.oneOf(*[ Parser.terminalParser(expectedType, createNode=createNode) for expectedType in tokenTypes ], name='|'.join([t.value for t in tokenTypes]))
#
# # loop -> start item* end
# @staticmethod
# def loop(startParser, itemParser, endParser, createNode, name="loop"):
# def parse(input):
# items = []
# start = startParser(input)
# if start.result:
# while True:
# end = endParser(input)
# if end.result:
# return ParseResult.OK(createNode(start.node, items, end.node))
# item = itemParser(input)
# if not item.result:
# return ParseResult.FAIL()
# items.append(item.node)
#
# return ParseResult.FAIL()
#
# return Parser(parse, name, parsers=[startParser, itemParser, endParser])
#
# @staticmethod
# def doAssert(parser, expected, name="!!"):
# def parse(input):
# result = parser(input)
#
# if not result.result:
# found = f", found '{input.current().rawValue}'" if input.hasCurrent() else ''
#
# raise SyntaxException(f"Expected {expected}{found}", input.currentPos())
#
# return result
#
# return Parser(parse, name, parsers=parser)
#
# @staticmethod
# def optional(parser, name="??"):
# def parse(input):
# result = parser(input)
# if result.result:
# return result
#
# return ParseResult.OK(NoneNode())
#
# return Parser(parse, name, parsers=[parser])
#
# @staticmethod
# def epsilon():
# return lambda *args: ParseResult.OK(NoneNode())
#
# @staticmethod
# def many(parser, createNode, name="*"):
# def parse(input):
# results = []
# snap = input.snapshot()
# pos = input.currentPos()
# while True:
# result = parser(input)
# if result.result:
# results.append(result.node)
# snap = input.snapshot()
# else:
# input.reset(snap)
# return ParseResult.OK(createNode(results, pos) if len(results) > 0 else NoneNode())
#
# return Parser(parse, name, parsers=[parser])

View File

@@ -1,5 +1,5 @@
from smnp.ast.node.model import Node
from smnp.ast.parser import TerminalParser, OneOfParser, AllOfParser
from smnp.ast.parser import TerminalParser, OneOfParser, AllOfParser, OptionalParser, LoopParser
from smnp.error.base import SmnpException
from smnp.token.tokenizer import tokenize
from smnp.token.type import TokenType
@@ -7,30 +7,36 @@ from smnp.token.type import TokenType
def main():
try:
#stdLibraryEnv = loadStandardLibrary()
#Interpreter.interpretFile(sys.argv[1], printTokens=True, printAst=True, execute=False, baseEnvironment=None)
#draft()
# stdLibraryEnv = loadStandardLibrary()
# Interpreter.interpretFile(sys.argv[1], printTokens=True, printAst=True, execute=False, baseEnvironment=None)
# draft()
def node(*items):
n = Node((-1, -1))
n.children = items
return n
class TestNode(Node):
def __init__(self, children):
super().__init__((-1, -1))
self.children = children
tokens = tokenize(['=x'])
parser = AllOfParser(
OneOfParser(
TerminalParser(TokenType.ASSIGN),
TerminalParser(TokenType.ASTERISK),
name="assignOrAsterisk"
tokens = tokenize(['{*1^*1^}'])
parser = LoopParser(
TerminalParser(TokenType.OPEN_CURLY),
AllOfParser(
OneOfParser(
TerminalParser(TokenType.ASSIGN),
TerminalParser(TokenType.ASTERISK),
name="assignOrAsterisk"
),
OptionalParser(TerminalParser(TokenType.INTEGER), name="optInt"),
TerminalParser(TokenType.DASH),
name="aoaInt",
createNode=lambda a, b, c: TestNode([a, b, c])
),
TerminalParser(TokenType.INTEGER),
name="aoaInt",
createNode=node
TerminalParser(TokenType.CLOSE_CURLY),
createNode=lambda a, b, c: TestNode([a, b, c]),
name="block",
)
print(parser.grammar())
res = parser.parse(tokens)
print()
if res.result:
res.node.print()