python.EventSelectionConfig._ExprParser Class Reference

Collaboration diagram for python.EventSelectionConfig._ExprParser:

Public Member Functions
	__init__ (self, token_re)
	tokenize (self, text)
	parse (self, tokens)

Protected Member Functions
	_peek (self)
	_advance (self)
	_expect (self, kind)
	_parse_funcall (self)
	_parse_operand (self)
	_parse_sign (self)
	_parse_value (self)

Protected Attributes
	_token_re = token_re
list	_tokens = []
int	_pos = 0

Detailed Description

Small recursive-descent parser for EXPR selector expressions.

Definition at line 42 of file EventSelectionConfig.py.

Constructor & Destructor Documentation

__init__()

python.EventSelectionConfig._ExprParser.__init__	(		self,
			token_re )

Definition at line 45 of file EventSelectionConfig.py.

    def __init__(self, token_re):
        self._token_re = token_re
        self._tokens = []
        self._pos = 0
 

Member Function Documentation

_advance()

python.EventSelectionConfig._ExprParser._advance ( self )

protected

Definition at line 66 of file EventSelectionConfig.py.

    def _advance(self):
        token = self._tokens[self._pos]
        self._pos += 1
        return token
 

_expect()

python.EventSelectionConfig._ExprParser._expect ( self, kind )

protected

Definition at line 71 of file EventSelectionConfig.py.

    def _expect(self, kind):
        token = self._advance()
        if token[0] != kind:
            raise InconsistentSettingsError(
                f"[EventSelectionConfig] EXPR: expected {kind}, got '{token[1]}'")
        return token
 

_parse_funcall()

python.EventSelectionConfig._ExprParser._parse_funcall ( self )

protected

Definition at line 87 of file EventSelectionConfig.py.

    def _parse_funcall(self):
        variable = self._expect("ID")[1]
        self._expect("LP")
        operands = [self._parse_operand()]
        separator = None
        while self._peek()[0] in ("COMMA", "PLUS"):
            sep = "," if self._advance()[0] == "COMMA" else "+"
            if separator is None:
                separator = sep
            elif sep != separator:
                raise InconsistentSettingsError(
                    "[EventSelectionConfig] EXPR: cannot mix ',' and '+' separators")
            operands.append(self._parse_operand())
        self._expect("RP")
        return variable, separator, operands
 

_parse_operand()

python.EventSelectionConfig._ExprParser._parse_operand ( self )

protected

Definition at line 103 of file EventSelectionConfig.py.

    def _parse_operand(self):
        coll = self._expect("ID")[1]
        index = None
        if self._peek()[0] == "LB":
            self._advance()
            index = int(self._expect("NUM")[1])
            self._expect("RB")
        return coll, index
 

_parse_sign()

python.EventSelectionConfig._ExprParser._parse_sign ( self )

protected

Definition at line 112 of file EventSelectionConfig.py.

    def _parse_sign(self):
        token = self._advance()
        if token[0] not in ("LT", "GT", "EQ", "GE", "LE"):
            raise InconsistentSettingsError(
                f"[EventSelectionConfig] EXPR: expected a comparison operator, got '{token[1]}'")
        return token[0]
 

_parse_value()

python.EventSelectionConfig._ExprParser._parse_value ( self )

protected

Definition at line 119 of file EventSelectionConfig.py.

    def _parse_value(self):
        negative = False
        if self._peek()[0] == "MINUS":
            self._advance()
            negative = True
        value = float(self._expect("NUM")[1])
        return -value if negative else value
 
 
 

_peek()

python.EventSelectionConfig._ExprParser._peek ( self )

protected

Definition at line 63 of file EventSelectionConfig.py.

    def _peek(self):
        return self._tokens[self._pos]
 

parse()

python.EventSelectionConfig._ExprParser.parse	(		self,
			tokens )

Definition at line 78 of file EventSelectionConfig.py.

    def parse(self, tokens):
        self._tokens = tokens
        self._pos = 0
        variable, separator, operands = self._parse_funcall()
        sign = self._parse_sign()
        ref_value = self._parse_value()
        self._expect("END")
        return variable, separator, operands, sign, ref_value
 

tokenize()

python.EventSelectionConfig._ExprParser.tokenize	(		self,
			text )

Definition at line 50 of file EventSelectionConfig.py.

    def tokenize(self, text):
        tokens, pos = [], 0
        while pos < len(text):
            match = self._token_re.match(text, pos)
            if not match:
                raise InconsistentSettingsError(
                    f"[EventSelectionConfig] EXPR: cannot parse near '{text[pos:]}'")
            pos = match.end()
            if match.lastgroup != "WS":
                tokens.append((match.lastgroup, match.group()))
        tokens.append(("END", ""))
        return tokens
 

Member Data Documentation

_pos

int python.EventSelectionConfig._ExprParser._pos = 0

protected

Definition at line 48 of file EventSelectionConfig.py.

_token_re

python.EventSelectionConfig._ExprParser._token_re = token_re

protected

Definition at line 46 of file EventSelectionConfig.py.

_tokens

list python.EventSelectionConfig._ExprParser._tokens = []

protected

Definition at line 47 of file EventSelectionConfig.py.

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The documentation for this class was generated from the following file:

• EventSelectionConfig.py