870 lines
29 KiB
Python
870 lines
29 KiB
Python
"""Implements a Jinja / Python combination lexer. The ``Lexer`` class
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is used to do some preprocessing. It filters out invalid operators like
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the bitshift operators we don't allow in templates. It separates
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template code and python code in expressions.
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"""
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import re
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import typing as t
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from ast import literal_eval
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from collections import deque
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from sys import intern
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from ._identifier import pattern as name_re
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from .exceptions import TemplateSyntaxError
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from .utils import LRUCache
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if t.TYPE_CHECKING:
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import typing_extensions as te
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from .environment import Environment
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# cache for the lexers. Exists in order to be able to have multiple
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# environments with the same lexer
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_lexer_cache: t.MutableMapping[t.Tuple, "Lexer"] = LRUCache(50) # type: ignore
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# static regular expressions
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whitespace_re = re.compile(r"\s+")
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newline_re = re.compile(r"(\r\n|\r|\n)")
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string_re = re.compile(
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r"('([^'\\]*(?:\\.[^'\\]*)*)'" r'|"([^"\\]*(?:\\.[^"\\]*)*)")', re.S
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)
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integer_re = re.compile(
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r"""
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(
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0b(_?[0-1])+ # binary
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0o(_?[0-7])+ # octal
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0x(_?[\da-f])+ # hex
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[1-9](_?\d)* # decimal
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0(_?0)* # decimal zero
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)
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""",
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re.IGNORECASE | re.VERBOSE,
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)
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float_re = re.compile(
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r"""
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(?<!\.) # doesn't start with a .
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(\d+_)*\d+ # digits, possibly _ separated
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(
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(\.(\d+_)*\d+)? # optional fractional part
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e[+\-]?(\d+_)*\d+ # exponent part
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\.(\d+_)*\d+ # required fractional part
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)
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""",
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re.IGNORECASE | re.VERBOSE,
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)
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# internal the tokens and keep references to them
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TOKEN_ADD = intern("add")
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TOKEN_ASSIGN = intern("assign")
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TOKEN_COLON = intern("colon")
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TOKEN_COMMA = intern("comma")
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TOKEN_DIV = intern("div")
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TOKEN_DOT = intern("dot")
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TOKEN_EQ = intern("eq")
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TOKEN_FLOORDIV = intern("floordiv")
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TOKEN_GT = intern("gt")
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TOKEN_GTEQ = intern("gteq")
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TOKEN_LBRACE = intern("lbrace")
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TOKEN_LBRACKET = intern("lbracket")
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TOKEN_LPAREN = intern("lparen")
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TOKEN_LT = intern("lt")
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TOKEN_LTEQ = intern("lteq")
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TOKEN_MOD = intern("mod")
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TOKEN_MUL = intern("mul")
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TOKEN_NE = intern("ne")
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TOKEN_PIPE = intern("pipe")
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TOKEN_POW = intern("pow")
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TOKEN_RBRACE = intern("rbrace")
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TOKEN_RBRACKET = intern("rbracket")
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TOKEN_RPAREN = intern("rparen")
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TOKEN_SEMICOLON = intern("semicolon")
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TOKEN_SUB = intern("sub")
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TOKEN_TILDE = intern("tilde")
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TOKEN_WHITESPACE = intern("whitespace")
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TOKEN_FLOAT = intern("float")
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TOKEN_INTEGER = intern("integer")
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TOKEN_NAME = intern("name")
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TOKEN_STRING = intern("string")
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TOKEN_OPERATOR = intern("operator")
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TOKEN_BLOCK_BEGIN = intern("block_begin")
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TOKEN_BLOCK_END = intern("block_end")
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TOKEN_VARIABLE_BEGIN = intern("variable_begin")
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TOKEN_VARIABLE_END = intern("variable_end")
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TOKEN_RAW_BEGIN = intern("raw_begin")
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TOKEN_RAW_END = intern("raw_end")
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TOKEN_COMMENT_BEGIN = intern("comment_begin")
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TOKEN_COMMENT_END = intern("comment_end")
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TOKEN_COMMENT = intern("comment")
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TOKEN_LINESTATEMENT_BEGIN = intern("linestatement_begin")
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TOKEN_LINESTATEMENT_END = intern("linestatement_end")
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TOKEN_LINECOMMENT_BEGIN = intern("linecomment_begin")
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TOKEN_LINECOMMENT_END = intern("linecomment_end")
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TOKEN_LINECOMMENT = intern("linecomment")
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TOKEN_DATA = intern("data")
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TOKEN_INITIAL = intern("initial")
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TOKEN_EOF = intern("eof")
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# bind operators to token types
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operators = {
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"+": TOKEN_ADD,
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"-": TOKEN_SUB,
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"/": TOKEN_DIV,
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"//": TOKEN_FLOORDIV,
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"*": TOKEN_MUL,
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"%": TOKEN_MOD,
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"**": TOKEN_POW,
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"~": TOKEN_TILDE,
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"[": TOKEN_LBRACKET,
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"]": TOKEN_RBRACKET,
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"(": TOKEN_LPAREN,
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")": TOKEN_RPAREN,
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"{": TOKEN_LBRACE,
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"}": TOKEN_RBRACE,
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"==": TOKEN_EQ,
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"!=": TOKEN_NE,
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">": TOKEN_GT,
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">=": TOKEN_GTEQ,
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"<": TOKEN_LT,
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"<=": TOKEN_LTEQ,
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"=": TOKEN_ASSIGN,
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".": TOKEN_DOT,
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":": TOKEN_COLON,
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"|": TOKEN_PIPE,
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",": TOKEN_COMMA,
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";": TOKEN_SEMICOLON,
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}
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reverse_operators = {v: k for k, v in operators.items()}
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assert len(operators) == len(reverse_operators), "operators dropped"
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operator_re = re.compile(
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f"({'|'.join(re.escape(x) for x in sorted(operators, key=lambda x: -len(x)))})"
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)
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ignored_tokens = frozenset(
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[
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TOKEN_COMMENT_BEGIN,
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TOKEN_COMMENT,
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TOKEN_COMMENT_END,
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TOKEN_WHITESPACE,
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TOKEN_LINECOMMENT_BEGIN,
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TOKEN_LINECOMMENT_END,
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TOKEN_LINECOMMENT,
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]
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)
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ignore_if_empty = frozenset(
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[TOKEN_WHITESPACE, TOKEN_DATA, TOKEN_COMMENT, TOKEN_LINECOMMENT]
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)
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def _describe_token_type(token_type: str) -> str:
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if token_type in reverse_operators:
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return reverse_operators[token_type]
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return {
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TOKEN_COMMENT_BEGIN: "begin of comment",
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TOKEN_COMMENT_END: "end of comment",
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TOKEN_COMMENT: "comment",
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TOKEN_LINECOMMENT: "comment",
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TOKEN_BLOCK_BEGIN: "begin of statement block",
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TOKEN_BLOCK_END: "end of statement block",
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TOKEN_VARIABLE_BEGIN: "begin of print statement",
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TOKEN_VARIABLE_END: "end of print statement",
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TOKEN_LINESTATEMENT_BEGIN: "begin of line statement",
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TOKEN_LINESTATEMENT_END: "end of line statement",
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TOKEN_DATA: "template data / text",
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TOKEN_EOF: "end of template",
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}.get(token_type, token_type)
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def describe_token(token: "Token") -> str:
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"""Returns a description of the token."""
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if token.type == TOKEN_NAME:
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return token.value
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return _describe_token_type(token.type)
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def describe_token_expr(expr: str) -> str:
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"""Like `describe_token` but for token expressions."""
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if ":" in expr:
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type, value = expr.split(":", 1)
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if type == TOKEN_NAME:
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return value
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else:
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type = expr
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return _describe_token_type(type)
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def count_newlines(value: str) -> int:
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"""Count the number of newline characters in the string. This is
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useful for extensions that filter a stream.
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"""
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return len(newline_re.findall(value))
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def compile_rules(environment: "Environment") -> t.List[t.Tuple[str, str]]:
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"""Compiles all the rules from the environment into a list of rules."""
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e = re.escape
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rules = [
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(
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len(environment.comment_start_string),
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TOKEN_COMMENT_BEGIN,
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e(environment.comment_start_string),
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),
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(
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len(environment.block_start_string),
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TOKEN_BLOCK_BEGIN,
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e(environment.block_start_string),
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),
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(
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len(environment.variable_start_string),
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TOKEN_VARIABLE_BEGIN,
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e(environment.variable_start_string),
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),
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]
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if environment.line_statement_prefix is not None:
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rules.append(
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(
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len(environment.line_statement_prefix),
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TOKEN_LINESTATEMENT_BEGIN,
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r"^[ \t\v]*" + e(environment.line_statement_prefix),
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)
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)
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if environment.line_comment_prefix is not None:
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rules.append(
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(
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len(environment.line_comment_prefix),
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TOKEN_LINECOMMENT_BEGIN,
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r"(?:^|(?<=\S))[^\S\r\n]*" + e(environment.line_comment_prefix),
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)
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)
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return [x[1:] for x in sorted(rules, reverse=True)]
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class Failure:
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"""Class that raises a `TemplateSyntaxError` if called.
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Used by the `Lexer` to specify known errors.
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"""
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def __init__(
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self, message: str, cls: t.Type[TemplateSyntaxError] = TemplateSyntaxError
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) -> None:
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self.message = message
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self.error_class = cls
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def __call__(self, lineno: int, filename: str) -> "te.NoReturn":
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raise self.error_class(self.message, lineno, filename)
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class Token(t.NamedTuple):
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lineno: int
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type: str
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value: str
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def __str__(self) -> str:
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return describe_token(self)
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def test(self, expr: str) -> bool:
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"""Test a token against a token expression. This can either be a
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token type or ``'token_type:token_value'``. This can only test
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against string values and types.
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"""
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# here we do a regular string equality check as test_any is usually
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# passed an iterable of not interned strings.
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if self.type == expr:
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return True
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if ":" in expr:
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return expr.split(":", 1) == [self.type, self.value]
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return False
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def test_any(self, *iterable: str) -> bool:
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"""Test against multiple token expressions."""
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return any(self.test(expr) for expr in iterable)
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class TokenStreamIterator:
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"""The iterator for tokenstreams. Iterate over the stream
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until the eof token is reached.
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"""
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def __init__(self, stream: "TokenStream") -> None:
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self.stream = stream
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def __iter__(self) -> "TokenStreamIterator":
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return self
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def __next__(self) -> Token:
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token = self.stream.current
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if token.type is TOKEN_EOF:
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self.stream.close()
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raise StopIteration
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next(self.stream)
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return token
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class TokenStream:
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"""A token stream is an iterable that yields :class:`Token`\\s. The
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parser however does not iterate over it but calls :meth:`next` to go
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one token ahead. The current active token is stored as :attr:`current`.
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"""
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def __init__(
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self,
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generator: t.Iterable[Token],
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name: t.Optional[str],
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filename: t.Optional[str],
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):
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self._iter = iter(generator)
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self._pushed: "te.Deque[Token]" = deque()
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self.name = name
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self.filename = filename
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self.closed = False
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self.current = Token(1, TOKEN_INITIAL, "")
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next(self)
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def __iter__(self) -> TokenStreamIterator:
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return TokenStreamIterator(self)
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def __bool__(self) -> bool:
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return bool(self._pushed) or self.current.type is not TOKEN_EOF
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@property
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def eos(self) -> bool:
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"""Are we at the end of the stream?"""
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return not self
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def push(self, token: Token) -> None:
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"""Push a token back to the stream."""
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self._pushed.append(token)
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def look(self) -> Token:
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"""Look at the next token."""
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old_token = next(self)
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result = self.current
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self.push(result)
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self.current = old_token
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return result
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def skip(self, n: int = 1) -> None:
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"""Got n tokens ahead."""
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for _ in range(n):
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next(self)
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def next_if(self, expr: str) -> t.Optional[Token]:
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"""Perform the token test and return the token if it matched.
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Otherwise the return value is `None`.
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"""
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if self.current.test(expr):
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return next(self)
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return None
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def skip_if(self, expr: str) -> bool:
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"""Like :meth:`next_if` but only returns `True` or `False`."""
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return self.next_if(expr) is not None
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def __next__(self) -> Token:
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"""Go one token ahead and return the old one.
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Use the built-in :func:`next` instead of calling this directly.
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"""
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rv = self.current
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if self._pushed:
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self.current = self._pushed.popleft()
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elif self.current.type is not TOKEN_EOF:
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try:
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self.current = next(self._iter)
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except StopIteration:
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self.close()
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return rv
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def close(self) -> None:
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"""Close the stream."""
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self.current = Token(self.current.lineno, TOKEN_EOF, "")
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self._iter = iter(())
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self.closed = True
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def expect(self, expr: str) -> Token:
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"""Expect a given token type and return it. This accepts the same
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argument as :meth:`jinja2.lexer.Token.test`.
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"""
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if not self.current.test(expr):
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expr = describe_token_expr(expr)
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if self.current.type is TOKEN_EOF:
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raise TemplateSyntaxError(
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f"unexpected end of template, expected {expr!r}.",
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self.current.lineno,
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self.name,
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self.filename,
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)
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raise TemplateSyntaxError(
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f"expected token {expr!r}, got {describe_token(self.current)!r}",
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self.current.lineno,
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self.name,
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self.filename,
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)
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return next(self)
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def get_lexer(environment: "Environment") -> "Lexer":
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"""Return a lexer which is probably cached."""
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key = (
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environment.block_start_string,
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environment.block_end_string,
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environment.variable_start_string,
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environment.variable_end_string,
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environment.comment_start_string,
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environment.comment_end_string,
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environment.line_statement_prefix,
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environment.line_comment_prefix,
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environment.trim_blocks,
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environment.lstrip_blocks,
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environment.newline_sequence,
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environment.keep_trailing_newline,
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)
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lexer = _lexer_cache.get(key)
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if lexer is None:
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_lexer_cache[key] = lexer = Lexer(environment)
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return lexer
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class OptionalLStrip(tuple):
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"""A special tuple for marking a point in the state that can have
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lstrip applied.
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"""
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__slots__ = ()
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# Even though it looks like a no-op, creating instances fails
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# without this.
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def __new__(cls, *members, **kwargs): # type: ignore
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return super().__new__(cls, members)
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class _Rule(t.NamedTuple):
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pattern: t.Pattern[str]
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tokens: t.Union[str, t.Tuple[str, ...], t.Tuple[Failure]]
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command: t.Optional[str]
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class Lexer:
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"""Class that implements a lexer for a given environment. Automatically
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created by the environment class, usually you don't have to do that.
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Note that the lexer is not automatically bound to an environment.
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Multiple environments can share the same lexer.
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"""
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def __init__(self, environment: "Environment") -> None:
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# shortcuts
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e = re.escape
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def c(x: str) -> t.Pattern[str]:
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return re.compile(x, re.M | re.S)
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# lexing rules for tags
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tag_rules: t.List[_Rule] = [
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_Rule(whitespace_re, TOKEN_WHITESPACE, None),
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_Rule(float_re, TOKEN_FLOAT, None),
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_Rule(integer_re, TOKEN_INTEGER, None),
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_Rule(name_re, TOKEN_NAME, None),
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_Rule(string_re, TOKEN_STRING, None),
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_Rule(operator_re, TOKEN_OPERATOR, None),
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]
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# assemble the root lexing rule. because "|" is ungreedy
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# we have to sort by length so that the lexer continues working
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# as expected when we have parsing rules like <% for block and
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# <%= for variables. (if someone wants asp like syntax)
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# variables are just part of the rules if variable processing
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# is required.
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root_tag_rules = compile_rules(environment)
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block_start_re = e(environment.block_start_string)
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block_end_re = e(environment.block_end_string)
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comment_end_re = e(environment.comment_end_string)
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variable_end_re = e(environment.variable_end_string)
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# block suffix if trimming is enabled
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block_suffix_re = "\\n?" if environment.trim_blocks else ""
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# If lstrip is enabled, it should not be applied if there is any
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# non-whitespace between the newline and block.
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self.lstrip_unless_re = c(r"[^ \t]") if environment.lstrip_blocks else None
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self.newline_sequence = environment.newline_sequence
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self.keep_trailing_newline = environment.keep_trailing_newline
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root_raw_re = (
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fr"(?P<raw_begin>{block_start_re}(\-|\+|)\s*raw\s*"
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fr"(?:\-{block_end_re}\s*|{block_end_re}))"
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)
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root_parts_re = "|".join(
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[root_raw_re] + [fr"(?P<{n}>{r}(\-|\+|))" for n, r in root_tag_rules]
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)
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# global lexing rules
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self.rules: t.Dict[str, t.List[_Rule]] = {
|
|
"root": [
|
|
# directives
|
|
_Rule(
|
|
c(fr"(.*?)(?:{root_parts_re})"),
|
|
OptionalLStrip(TOKEN_DATA, "#bygroup"), # type: ignore
|
|
"#bygroup",
|
|
),
|
|
# data
|
|
_Rule(c(".+"), TOKEN_DATA, None),
|
|
],
|
|
# comments
|
|
TOKEN_COMMENT_BEGIN: [
|
|
_Rule(
|
|
c(
|
|
fr"(.*?)((?:\+{comment_end_re}|\-{comment_end_re}\s*"
|
|
fr"|{comment_end_re}{block_suffix_re}))"
|
|
),
|
|
(TOKEN_COMMENT, TOKEN_COMMENT_END),
|
|
"#pop",
|
|
),
|
|
_Rule(c(r"(.)"), (Failure("Missing end of comment tag"),), None),
|
|
],
|
|
# blocks
|
|
TOKEN_BLOCK_BEGIN: [
|
|
_Rule(
|
|
c(
|
|
fr"(?:\+{block_end_re}|\-{block_end_re}\s*"
|
|
fr"|{block_end_re}{block_suffix_re})"
|
|
),
|
|
TOKEN_BLOCK_END,
|
|
"#pop",
|
|
),
|
|
]
|
|
+ tag_rules,
|
|
# variables
|
|
TOKEN_VARIABLE_BEGIN: [
|
|
_Rule(
|
|
c(fr"\-{variable_end_re}\s*|{variable_end_re}"),
|
|
TOKEN_VARIABLE_END,
|
|
"#pop",
|
|
)
|
|
]
|
|
+ tag_rules,
|
|
# raw block
|
|
TOKEN_RAW_BEGIN: [
|
|
_Rule(
|
|
c(
|
|
fr"(.*?)((?:{block_start_re}(\-|\+|))\s*endraw\s*"
|
|
fr"(?:\+{block_end_re}|\-{block_end_re}\s*"
|
|
fr"|{block_end_re}{block_suffix_re}))"
|
|
),
|
|
OptionalLStrip(TOKEN_DATA, TOKEN_RAW_END), # type: ignore
|
|
"#pop",
|
|
),
|
|
_Rule(c(r"(.)"), (Failure("Missing end of raw directive"),), None),
|
|
],
|
|
# line statements
|
|
TOKEN_LINESTATEMENT_BEGIN: [
|
|
_Rule(c(r"\s*(\n|$)"), TOKEN_LINESTATEMENT_END, "#pop")
|
|
]
|
|
+ tag_rules,
|
|
# line comments
|
|
TOKEN_LINECOMMENT_BEGIN: [
|
|
_Rule(
|
|
c(r"(.*?)()(?=\n|$)"),
|
|
(TOKEN_LINECOMMENT, TOKEN_LINECOMMENT_END),
|
|
"#pop",
|
|
)
|
|
],
|
|
}
|
|
|
|
def _normalize_newlines(self, value: str) -> str:
|
|
"""Replace all newlines with the configured sequence in strings
|
|
and template data.
|
|
"""
|
|
return newline_re.sub(self.newline_sequence, value)
|
|
|
|
def tokenize(
|
|
self,
|
|
source: str,
|
|
name: t.Optional[str] = None,
|
|
filename: t.Optional[str] = None,
|
|
state: t.Optional[str] = None,
|
|
) -> TokenStream:
|
|
"""Calls tokeniter + tokenize and wraps it in a token stream."""
|
|
stream = self.tokeniter(source, name, filename, state)
|
|
return TokenStream(self.wrap(stream, name, filename), name, filename)
|
|
|
|
def wrap(
|
|
self,
|
|
stream: t.Iterable[t.Tuple[int, str, str]],
|
|
name: t.Optional[str] = None,
|
|
filename: t.Optional[str] = None,
|
|
) -> t.Iterator[Token]:
|
|
"""This is called with the stream as returned by `tokenize` and wraps
|
|
every token in a :class:`Token` and converts the value.
|
|
"""
|
|
for lineno, token, value_str in stream:
|
|
if token in ignored_tokens:
|
|
continue
|
|
|
|
value: t.Any = value_str
|
|
|
|
if token == TOKEN_LINESTATEMENT_BEGIN:
|
|
token = TOKEN_BLOCK_BEGIN
|
|
elif token == TOKEN_LINESTATEMENT_END:
|
|
token = TOKEN_BLOCK_END
|
|
# we are not interested in those tokens in the parser
|
|
elif token in (TOKEN_RAW_BEGIN, TOKEN_RAW_END):
|
|
continue
|
|
elif token == TOKEN_DATA:
|
|
value = self._normalize_newlines(value_str)
|
|
elif token == "keyword":
|
|
token = value_str
|
|
elif token == TOKEN_NAME:
|
|
value = value_str
|
|
|
|
if not value.isidentifier():
|
|
raise TemplateSyntaxError(
|
|
"Invalid character in identifier", lineno, name, filename
|
|
)
|
|
elif token == TOKEN_STRING:
|
|
# try to unescape string
|
|
try:
|
|
value = (
|
|
self._normalize_newlines(value_str[1:-1])
|
|
.encode("ascii", "backslashreplace")
|
|
.decode("unicode-escape")
|
|
)
|
|
except Exception as e:
|
|
msg = str(e).split(":")[-1].strip()
|
|
raise TemplateSyntaxError(msg, lineno, name, filename) from e
|
|
elif token == TOKEN_INTEGER:
|
|
value = int(value_str.replace("_", ""), 0)
|
|
elif token == TOKEN_FLOAT:
|
|
# remove all "_" first to support more Python versions
|
|
value = literal_eval(value_str.replace("_", ""))
|
|
elif token == TOKEN_OPERATOR:
|
|
token = operators[value_str]
|
|
|
|
yield Token(lineno, token, value)
|
|
|
|
def tokeniter(
|
|
self,
|
|
source: str,
|
|
name: t.Optional[str],
|
|
filename: t.Optional[str] = None,
|
|
state: t.Optional[str] = None,
|
|
) -> t.Iterator[t.Tuple[int, str, str]]:
|
|
"""This method tokenizes the text and returns the tokens in a
|
|
generator. Use this method if you just want to tokenize a template.
|
|
|
|
.. versionchanged:: 3.0
|
|
Only ``\\n``, ``\\r\\n`` and ``\\r`` are treated as line
|
|
breaks.
|
|
"""
|
|
lines = newline_re.split(source)[::2]
|
|
|
|
if not self.keep_trailing_newline and lines[-1] == "":
|
|
del lines[-1]
|
|
|
|
source = "\n".join(lines)
|
|
pos = 0
|
|
lineno = 1
|
|
stack = ["root"]
|
|
|
|
if state is not None and state != "root":
|
|
assert state in ("variable", "block"), "invalid state"
|
|
stack.append(state + "_begin")
|
|
|
|
statetokens = self.rules[stack[-1]]
|
|
source_length = len(source)
|
|
balancing_stack: t.List[str] = []
|
|
lstrip_unless_re = self.lstrip_unless_re
|
|
newlines_stripped = 0
|
|
line_starting = True
|
|
|
|
while True:
|
|
# tokenizer loop
|
|
for regex, tokens, new_state in statetokens:
|
|
m = regex.match(source, pos)
|
|
|
|
# if no match we try again with the next rule
|
|
if m is None:
|
|
continue
|
|
|
|
# we only match blocks and variables if braces / parentheses
|
|
# are balanced. continue parsing with the lower rule which
|
|
# is the operator rule. do this only if the end tags look
|
|
# like operators
|
|
if balancing_stack and tokens in (
|
|
TOKEN_VARIABLE_END,
|
|
TOKEN_BLOCK_END,
|
|
TOKEN_LINESTATEMENT_END,
|
|
):
|
|
continue
|
|
|
|
# tuples support more options
|
|
if isinstance(tokens, tuple):
|
|
groups = m.groups()
|
|
|
|
if isinstance(tokens, OptionalLStrip):
|
|
# Rule supports lstrip. Match will look like
|
|
# text, block type, whitespace control, type, control, ...
|
|
text = groups[0]
|
|
# Skipping the text and first type, every other group is the
|
|
# whitespace control for each type. One of the groups will be
|
|
# -, +, or empty string instead of None.
|
|
strip_sign = next(g for g in groups[2::2] if g is not None)
|
|
|
|
if strip_sign == "-":
|
|
# Strip all whitespace between the text and the tag.
|
|
stripped = text.rstrip()
|
|
newlines_stripped = text[len(stripped) :].count("\n")
|
|
groups = [stripped, *groups[1:]]
|
|
elif (
|
|
# Not marked for preserving whitespace.
|
|
strip_sign != "+"
|
|
# lstrip is enabled.
|
|
and lstrip_unless_re is not None
|
|
# Not a variable expression.
|
|
and not m.groupdict().get(TOKEN_VARIABLE_BEGIN)
|
|
):
|
|
# The start of text between the last newline and the tag.
|
|
l_pos = text.rfind("\n") + 1
|
|
|
|
if l_pos > 0 or line_starting:
|
|
# If there's only whitespace between the newline and the
|
|
# tag, strip it.
|
|
if not lstrip_unless_re.search(text, l_pos):
|
|
groups = [text[:l_pos], *groups[1:]]
|
|
|
|
for idx, token in enumerate(tokens):
|
|
# failure group
|
|
if token.__class__ is Failure:
|
|
raise token(lineno, filename)
|
|
# bygroup is a bit more complex, in that case we
|
|
# yield for the current token the first named
|
|
# group that matched
|
|
elif token == "#bygroup":
|
|
for key, value in m.groupdict().items():
|
|
if value is not None:
|
|
yield lineno, key, value
|
|
lineno += value.count("\n")
|
|
break
|
|
else:
|
|
raise RuntimeError(
|
|
f"{regex!r} wanted to resolve the token dynamically"
|
|
" but no group matched"
|
|
)
|
|
# normal group
|
|
else:
|
|
data = groups[idx]
|
|
|
|
if data or token not in ignore_if_empty:
|
|
yield lineno, token, data
|
|
|
|
lineno += data.count("\n") + newlines_stripped
|
|
newlines_stripped = 0
|
|
|
|
# strings as token just are yielded as it.
|
|
else:
|
|
data = m.group()
|
|
|
|
# update brace/parentheses balance
|
|
if tokens == TOKEN_OPERATOR:
|
|
if data == "{":
|
|
balancing_stack.append("}")
|
|
elif data == "(":
|
|
balancing_stack.append(")")
|
|
elif data == "[":
|
|
balancing_stack.append("]")
|
|
elif data in ("}", ")", "]"):
|
|
if not balancing_stack:
|
|
raise TemplateSyntaxError(
|
|
f"unexpected '{data}'", lineno, name, filename
|
|
)
|
|
|
|
expected_op = balancing_stack.pop()
|
|
|
|
if expected_op != data:
|
|
raise TemplateSyntaxError(
|
|
f"unexpected '{data}', expected '{expected_op}'",
|
|
lineno,
|
|
name,
|
|
filename,
|
|
)
|
|
|
|
# yield items
|
|
if data or tokens not in ignore_if_empty:
|
|
yield lineno, tokens, data
|
|
|
|
lineno += data.count("\n")
|
|
|
|
line_starting = m.group()[-1:] == "\n"
|
|
# fetch new position into new variable so that we can check
|
|
# if there is a internal parsing error which would result
|
|
# in an infinite loop
|
|
pos2 = m.end()
|
|
|
|
# handle state changes
|
|
if new_state is not None:
|
|
# remove the uppermost state
|
|
if new_state == "#pop":
|
|
stack.pop()
|
|
# resolve the new state by group checking
|
|
elif new_state == "#bygroup":
|
|
for key, value in m.groupdict().items():
|
|
if value is not None:
|
|
stack.append(key)
|
|
break
|
|
else:
|
|
raise RuntimeError(
|
|
f"{regex!r} wanted to resolve the new state dynamically"
|
|
f" but no group matched"
|
|
)
|
|
# direct state name given
|
|
else:
|
|
stack.append(new_state)
|
|
|
|
statetokens = self.rules[stack[-1]]
|
|
# we are still at the same position and no stack change.
|
|
# this means a loop without break condition, avoid that and
|
|
# raise error
|
|
elif pos2 == pos:
|
|
raise RuntimeError(
|
|
f"{regex!r} yielded empty string without stack change"
|
|
)
|
|
|
|
# publish new function and start again
|
|
pos = pos2
|
|
break
|
|
# if loop terminated without break we haven't found a single match
|
|
# either we are at the end of the file or we have a problem
|
|
else:
|
|
# end of text
|
|
if pos >= source_length:
|
|
return
|
|
|
|
# something went wrong
|
|
raise TemplateSyntaxError(
|
|
f"unexpected char {source[pos]!r} at {pos}", lineno, name, filename
|
|
)
|