def _ReadArithExpr(self):
"""Read and parse an arithmetic expression in various contexts.
$(( 1+2 ))
(( a=1+2 ))
${a[ 1+2 ]}
${a : 1+2 : 1+2}
See tests/arith-context.test.sh for ambiguous cases.
${a[a[0]]} is valid # VS_RBRACKET vs Id.Arith_RBracket
${s : a<b?0:1 : 1} # VS_COLON vs Id.Arith_Colon
TODO: Instead of having an eof_type. I think we should use just run the
arith parser until it's done. That will take care of both : and ]. We
switch the state back.
See the assertion in ArithParser.Parse() -- unexpected extra input.
"""
# calls self.ReadWord(lex_mode_e.Arith)
a_parser = tdop.TdopParser(arith_parse.SPEC, self)
anode = a_parser.Parse()
assert anode is not None
return anode # could be None
def MakeArithParser(self, code_str):
# type: (str) -> TdopParser
"""Used for a[x+1]=foo in the CommandParser."""
line_reader = reader.StringLineReader(code_str, self.arena)
lx = self._MakeLexer(line_reader)
w_parser = word_parse.WordParser(self,
lx,
line_reader,
lex_mode=lex_mode_e.Arith)
a_parser = tdop.TdopParser(arith_parse.SPEC, w_parser)
return a_parser
def MakeArithParser(self, code_str, arena):
"""Used for a[x+1]=foo in the CommandParser.
NOTE: We add tokens to a different arena, so we don't mess up the
invariants for translation.
"""
line_reader = reader.StringLineReader(code_str, arena)
lx = self._MakeLexer(line_reader, arena=arena)
w_parser = word_parse.WordParser(self, lx, line_reader,
lex_mode=lex_mode_e.Arith)
a_parser = tdop.TdopParser(arith_parse.SPEC, w_parser)
return a_parser
