On 24 Jan 2006, at 16:11, Mili Sandokan wrote:
I know how to set precedence between tokens but i'm asking how to do
this when the " . " is between two non-terminals.... ¿can I show you
a piece of the output file?
I do not remember the details how it works, and further, the method
does not have the capacity of resolving all shift/reduce conflicts.
81 s_condicional: T_IF '(' expresion ')' . sentencia_o_nada
82 | T_IF '(' expresion ')' . sentencia_o_nada T_ELSE
In this case, the tokens closest to the '.' are ')' and T_ELSE; so
you should have token precedences set on those two. If you rewrite
the rule as:
cond: IF bool_expr THEN expr
cond: IF bool_expr THEN expr ELSE expr
then the tokens closest to '.', will be, I think THEN and ELSE, and
token precedences should be set ointo those.
So it is a very primitive method of resolving shift/resolve conflict,
that doe not depend only the grammar, but how it is written in the
form of rules.
Hans Aberg
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