> Le 15 avr. 2020 à 18:15, Hans Åberg <[email protected]> a écrit :
>>>> In retrospect, it would have been better to have it named "token_type",
>>>> and "stack_symbol_type" would have been "symbol_type".
>>>
>>> Maybe so. I only need the symbol value for the return to the parser from
>>> the lexer, and mostly, they are symbol constants (tokens), but I am not
>>> sure they always have to be.
>>
>> So that's the kind.
>
> I think it is unkind! :-) The word “kind” does not seem to be in line with
> any C++ lingo at least.
The parser is fed with tokens by yylex. A lexeme such as "123" in an
arithmetical expression, has:
- a kind, NUMBER. That coincides with what people refer to as a "token" when
they talk about the grammar.
- a value, the int 100 + 20 + 3.
- a location, from Line 1 Col 1 to Line 1 Col 4 (excluded)
The type of the kind is token_kind_type, the type of the value is value_type,
and the type of the location is location_type. The type of the kind is not
kind_type, because we actually deal with two kinds, so we must be clearer. But
there's only one concept of value_type and one of location_type.
And token_type denotes the type which is a triple: token_kind_type, value_type,
location_type.
yylex returns the kind, and takes pointers to yylval (value) and yylloc
(location).
Cheers!
