Souped up the lexer to track line & col numbers

This commit is contained in:
Emi Simpson 2023-03-04 17:04:23 -05:00
parent 61ee996c7a
commit 3afed0c2e0
Signed by: Emi
GPG key ID: A12F2C2FFDC3D847

73
lex.py
View file

@ -2,22 +2,32 @@ from emis_funky_funktions import *
from dataclasses import dataclass
from enum import auto, IntEnum
from operator import is_not
from operator import eq, is_not
from re import Pattern
from typing import Collection, Tuple, List, NewType
def try_lex1(regex: Pattern[str], tok: A, input: str) -> Option[Tuple[Tuple[A, str], str]]:
@dataclass(frozen=True)
class Lexeme(Generic[B]):
token: B
matched_string: str
line: int
col_start: int
col_end: int
def __repr__(self):
return f'[{repr(self.token)}: {repr(self.matched_string)}]@({self.line}, {self.col_start}-{self.col_end})'
def try_lex1(regex: Pattern[str], tok: A, input: str, line_no: int, col_no: int) -> Option[Tuple[Lexeme[A], str]]:
"""
Attempt to recognize a single token against a full input string
If successful, returns the token provided as an argument, the part of the input which
matched, and the rest of the input. Otherwise, returns `None`
>>> try_lex1(compile(r'\d+'), "NUMBER", "123abc")
Some((('NUMBER', '123'), 'abc'))
>>> try_lex1(compile(r'\d+'), "NUMBER", "123abc", 1, 1)
Some((['NUMBER': '123']@(1, 1-4), 'abc'))
>>> try_lex1(compile(r'\d+'), "NUMBER", "abc123") is None
>>> try_lex1(compile(r'\d+'), "NUMBER", "abc123", 1, 1) is None
True
"""
match regex.match(input):
@ -25,10 +35,14 @@ def try_lex1(regex: Pattern[str], tok: A, input: str) -> Option[Tuple[Tuple[A, s
return None
case match:
assert match is not None
return Some(((tok, match.group()), input[match.end():]))
return Some((Lexeme(tok, match.group(), line_no, col_no, col_no + match.end()), input[match.end():]))
def tokenize(lex_table: Collection[Tuple[Pattern[str], A]], drop_tokens: Collection[A], input: str, prefix: List[Tuple[A, str]] = []) -> Result[List[Tuple[A, str]], str]:
def tokenize(
lex_table: Collection[Tuple[Pattern[str], A]],
drop_tokens: Collection[A],
input: str
) -> Result[List[Lexeme[A]], str]:
"""
Attempt to lex an entire input string.
@ -41,30 +55,39 @@ def tokenize(lex_table: Collection[Tuple[Pattern[str], A]], drop_tokens: Collect
is returned containing the section of the input that failed to match.
>>> tokenize(LEX_TABLE, [Tok.Whitespace], 'Clauses: \\n!man(x5) person') #doctest: +NORMALIZE_WHITESPACE
Ok([(ClausesSection, 'Clauses:'), (Newline, '\\n'), (Negate, '!'),
(Identifier, 'man'), (OpenP, '('), (Identifier, 'x5'),
(CloseP, ')'), (Identifier, 'person')])
Ok([[ClausesSection: 'Clauses:']@(1, 1-9), [Newline: '\\n']@(1, 10-11),
[Negate: '!']@(2, 1-2), [Identifier: 'man']@(2, 2-5), [OpenP: '(']@(2, 5-6),
[Identifier: 'x5']@(2, 6-8), [CloseP: ')']@(2, 8-9),
[Identifier: 'person']@(2, 10-16)])
>>> tokenize(LEX_TABLE, [Tok.Whitespace], 'Clauses: \\n🍆 !man(x5)')
Err('🍆 !man(x5)')
"""
if len(input):
try:
lexeme, rest_input = next(
unwrap_opt(maybe_lexeme)
for maybe_lexeme in (
try_lex1(regex, tok, input)
for (regex, tok) in lex_table
def inner(input: str, line_no: int, col_no: int, prefix: List[Lexeme[A]]) -> Result[List[Lexeme[A]], str]:
if len(input):
try:
lexeme, rest_input = next(
unwrap_opt(maybe_lexeme)
for maybe_lexeme in (
try_lex1(regex, tok, input, line_no, col_no)
for (regex, tok) in lex_table
)
if isinstance(maybe_lexeme, Some)
)
if isinstance(maybe_lexeme, Some)
except StopIteration:
return Err(input)
if lexeme.token not in drop_tokens:
prefix.append(lexeme)
newline_count = len(list(filter(p(eq, '\n'), lexeme.matched_string)))
new_col_no = (
len(lexeme.matched_string) - lexeme.matched_string.rfind('\n')
if newline_count else
col_no + len(lexeme.matched_string)
)
except StopIteration:
return Err(input)
if lexeme[0] not in drop_tokens:
prefix.append(lexeme)
return tokenize(lex_table, drop_tokens, rest_input, prefix)
else:
return Ok(prefix)
return inner(rest_input, line_no+newline_count, new_col_no, prefix)
else:
return Ok(prefix)
return inner(input, 1, 1, [])
if __name__ == '__main__':