dbt-selly/dbt-env/lib/python3.8/site-packages/sqlparse/lexer.py

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2022-03-22 15:13:27 +00:00
#
# Copyright (C) 2009-2020 the sqlparse authors and contributors
# <see AUTHORS file>
#
# This module is part of python-sqlparse and is released under
# the BSD License: https://opensource.org/licenses/BSD-3-Clause
"""SQL Lexer"""
# This code is based on the SqlLexer in pygments.
# http://pygments.org/
# It's separated from the rest of pygments to increase performance
# and to allow some customizations.
from io import TextIOBase
from sqlparse import tokens
from sqlparse.keywords import SQL_REGEX
from sqlparse.utils import consume
class Lexer:
"""Lexer
Empty class. Leaving for backwards-compatibility
"""
@staticmethod
def get_tokens(text, encoding=None):
"""
Return an iterable of (tokentype, value) pairs generated from
`text`. If `unfiltered` is set to `True`, the filtering mechanism
is bypassed even if filters are defined.
Also preprocess the text, i.e. expand tabs and strip it if
wanted and applies registered filters.
Split ``text`` into (tokentype, text) pairs.
``stack`` is the initial stack (default: ``['root']``)
"""
if isinstance(text, TextIOBase):
text = text.read()
if isinstance(text, str):
pass
elif isinstance(text, bytes):
if encoding:
text = text.decode(encoding)
else:
try:
text = text.decode('utf-8')
except UnicodeDecodeError:
text = text.decode('unicode-escape')
else:
raise TypeError("Expected text or file-like object, got {!r}".
format(type(text)))
iterable = enumerate(text)
for pos, char in iterable:
for rexmatch, action in SQL_REGEX:
m = rexmatch(text, pos)
if not m:
continue
elif isinstance(action, tokens._TokenType):
yield action, m.group()
elif callable(action):
yield action(m.group())
consume(iterable, m.end() - pos - 1)
break
else:
yield tokens.Error, char
def tokenize(sql, encoding=None):
"""Tokenize sql.
Tokenize *sql* using the :class:`Lexer` and return a 2-tuple stream
of ``(token type, value)`` items.
"""
return Lexer().get_tokens(sql, encoding)