-"""
-config_parser.py
-------------
-
+r"""
Simple Moe configuration file syntax parser.
-TODO: decide neccessity of '()' in/around formulas
-TODO: check escaping in expressions
-TODO: should whitespace (incl. '\\n') be allowed (almost) everywhere?
- can comment be anywhere whitespace can?
+Generally, whitespace and comments are alowed everywhere except in variable names and inside expressions,
+``\\n`` ends a ``COMMENT``.
-Generally, whitespace and comments are alowed everywhere except in variable names and inside expressions.
-Also, COMMENT must not contain '\\n'.
+``FILE``, ``BLOCK``, ``STATEMENT``, ``OPERATION``, ``SUBTREE``, ``CONDITION``, ``FORMULA``, ``AND``, ``OR``
+and ``NOT`` ignore any preceding whitespace.
-FILE, BLOCK, STATEMENT, OPERATION, SUBTREE, CONDITION, FORMULA, AND, OR and NOT eat any preceding whitespace. TODO: check?
+.. highlight:: none
-The configuration syntax is the following:
+The configuration syntax is the following::
-FILE = BLOCK
-BLOCK = WS | STATEMENT ( SEP STATEMENT )*
+ FILE = BLOCK
+ BLOCK = WS | STATEMENT ( SEP STATEMENT )*
-SEP = ( '\\n' | ';' )
-WS = ( ' ' | '\\t' | '\\n' | COMMENT )*
+ SEP = ( '\n' | ';' )
+ WS = ( ' ' | '\t' | '\n' | COMMENT )*
-COMMENT = re('#[^\\n]*\\n')
+ COMMENT = re('#[^\n]*\n')
-STATEMENT = CONDITION | OPERATION | SUBTREE
+ STATEMENT = CONDITION | OPERATION | SUBTREE
-OPERATION = WS VARNAME WS ( '=' | '+=' ) WS EXPRESSION
-SUBTREE = WS VARNAME WS '{' BLOCK WS '}'
-CONDITION = WS 'if' FORMULA WS '{' BLOCK WS '}'
+ OPERATION = WS VARNAME WS ( '=' | '+=' ) WS EXPRESSION
+ SUBTREE = WS VARNAME WS '{' BLOCK WS '}'
+ CONDITION = WS 'if' FORMULA WS '{' BLOCK WS '}'
-FORMULA = WS (( EXPRESSION WS ( '!=' | '==' ) WS EXPRESSION ) | '(' AND WS ')' | '(' OR WS ')' | NOT )
-AND = FORMULA WS 'and' FORMULA
-OR = FORMULA WS 'or' FORMULA
-NOT = WS 'not' FORMULA
+ FORMULA = WS (( EXPRESSION WS ( '!=' | '==' ) WS EXPRESSION ) |
+ '(' AND WS ')' | '(' OR WS ')' | NOT )
+ AND = FORMULA WS 'and' FORMULA
+ OR = FORMULA WS 'or' FORMULA
+ NOT = WS 'not' FORMULA
-NOTE: ';' or '\n' is currently required even after CONDITION and SUBTREE block
- TODO: change to OPERATION only
-NOTE: Formula may contain additional/extra parentheses
+ EXPRESSION = '"' ( ECHAR | '{' VARNAME '}' )* '"' | re"'[^'\n]*'" | VARNAME
+ ECHAR = re('([^\{}]|\\|\{|\}|\\n)*')
+ VARNAME = re('[a-zA-Z0-9-_]+(\.[a-zA-Z0-9-_]+)*')
-EXPRESSION = '"' ( ECHAR | '{' VARNAME '}' )* '"' | re"'[^'\\n]*'" | VARNAME
-ECHAR = re('([^\\{}]|\\\\|\\{|\\}|\\n)*')
-VARNAME = re('[a-zA-Z0-9-_]+(\.[a-zA-Z0-9-_]+)*')
+.. todo:: should whitespace (incl. '\n') be allowed (almost) everywhere?
+ can comment be anywhere whitespace can?
+.. note:: ';' or '\n' is currently required even after CONDITION and SUBTREE block
+.. note:: Formula can contain additional/unnecessary parentheses
"""
import re, types, itertools, logging as log
import moe.config as cf
+def config_escape(s):
+ """
+ Escape any ``{``, ``}``, ``"`` and ``\\`` in the given string, making it safe for parsing.
+ """
+ s = s.replace('\\', '\\\\')
+ s = s.replace('{', '\\{')
+ s = s.replace('}', '\\}')
+ s = s.replace('"', '\\"')
+ return s
+
class ConfigSyntaxError(cf.ConfigError):
def __init__(self, msg, source='<unknown>', line=None, column=None):
op = 'SET'
elif self.nexts(self.c_append):
op = 'APPEND'
+ elif self.eof():
+ self.syntax_error('Unexpected end of file.')
else:
- self.syntax_error('Unknown operation.')
+ self.syntax_error('Unknown operation: %r...', self.peek(10))
self.p_WS()
exp = self.p_EXPRESSION()
vname = (self.prefix+self.c_varname_sep+varname).lstrip(self.c_varname_sep)