[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

C++ variants

From: Hans Aberg
Subject: C++ variants
Date: Sun, 18 Jan 2015 23:10:38 +0100

Bison C++ variants do not save the type, however, if one wants to put data in a 
lookup table or a return type, it may be needed. In the calc++ example .yy 
file, one might have types say bool b, integer z, and rational r (using GMP):
    "identifier" ":=“ b-exp { driver.variables[$1] = $3; };
    "identifier" ":=“ z-exp { driver.variables[$1] = $3; };
    "identifier" ":=“ q-exp { driver.variables[$1] = $3; };
and similarly for
  unit: assignments exp  { driver.result = $2; };

Do you have an example of that? - Before, I used a polymorphic type storing a 
pointer, but the idea is to avoid that in the case the parser is statically 

reply via email to

[Prev in Thread] Current Thread [Next in Thread]