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2.4.1 Declarations for ltcalc

The C and Bison declarations for the location tracking calculator are the same as the declarations for the infix notation calculator.

     /* Location tracking calculator.  */
       #include <math.h>
       int yylex (void);
       void yyerror (char const *);
     /* Bison declarations.  */
     %define api.value.type {int}
     %token NUM
     %left '-' '+'
     %left '*' '/'
     %precedence NEG
     %right '^'
     %% /* The grammar follows.  */

Note there are no declarations specific to locations. Defining a data type for storing locations is not needed: we will use the type provided by default (see Data Types of Locations), which is a four member structure with the following integer fields: first_line, first_column, last_line and last_column. By conventions, and in accordance with the GNU Coding Standards and common practice, the line and column count both start at 1.