using (char*) in switch statement

Question

I am new in C programming language and have an (if statement) and need to transfer it into switch statement. My problem is that I have a field named (node_kind) of char* type and I compare it's content in the if statement using (strcmp) but I don't know how to do that in the switch statement. Would you plz tell me how ? Here is a short quote of my program

if (strcmp(node->node_kind, "VAR_TOKEN_e") == 0) 
    job = visitor->visitjob_VAR_TOKEN; 
if (strcmp(node->node_kind, "INT_e") == 0) 
    job = visitor->visitjob_int; 
if (strcmp(node->node_kind, "BOOL_e") == 0) 
    job = visitor->visitjob_bool; 

Answer 1

You can use gperf (website) to generate a perfect hash, which turns strings into integers. You'll have something like this:

In your header file:

enum {
    STR_VAR_TOKEN_e,
    STR_INT_e,
    STR_BOOL_e
};
int get_index(char *str);

In your gperf file:

struct entry;
#include <string.h>
#include "header.h"
struct entry { char *name; int value; };
%language=ANSI-C
%struct-type
%%
VAR_TOKEN_e, STR_VAR_TOKEN_e
INT_e, STR_INT_e
BOOL_e, STR_BOOL_e
%%
int get_index(char *str)
{
    struct entry *e = in_word_set(str, strlen(str));
    return e ? e->value : -1;
}

In your switch statement:

switch (get_index(node->node_kind)) {
case STR_VAR_TOKEN_e: ...
...
}