I found this TS embedding (in C) example that emulates a prompted lisp tutorial. I had to add the simulated (quit) logic.
/**
* hello-scheme for illustration how to embed
* the tiny scheme interpreter in a C program
*
* 2012, OL
*/
#include <stdio.h>
#include <string.h>
#include "scheme.h"
#include "dynload.h"
/* scheme_load_string does not like
carriage returns so strip them out */
void strip_cr( char *p, int max_len )
{
int i;
for( i=0; i < max_len && p[i]!='\0'; ++i )
;
if( i > 0 && p[i-1]=='\n' )
p[i-1] = '\0';
}
/**
* illustration of a C function binding
*/
pointer func1(scheme *sc, pointer args)
{
pointer arg;
pointer retval;
char *strarg;
double realnumber;
int intnumber;
int i = 1;
while( args != sc->NIL )
{
if( is_string( arg = pair_car(args)) )
{
strarg = string_value( arg );
printf( "argument %d is string %s\n", i++, strarg );
}
else if( is_real( arg = pair_car(args) ) )
{
realnumber = rvalue( arg );
printf( "argument %d is real number %lf\n", i++, realnumber );
}
else if( is_integer( arg = pair_car(args) ) )
{
intnumber = ivalue( arg );
printf( "argument %d is integer number %d\n", i++, intnumber );
}
args = pair_cdr( args );
}
if( i > 1 )
retval = sc -> T;
else
retval = sc -> F;
return(retval);
}
/*
* Simple REPL
*/
int main( int argc, char* argv[] )
{
scheme sc;
char cmd_str[80];
/* intialize the scheme object */
if( !scheme_init(&sc) ) {
fprintf(stderr,"Could not initialize!\n");
return 2;
}
/* set standard input and output ports */
scheme_set_input_port_file(&sc, stdin);
scheme_set_output_port_file(&sc, stdout);
/* illustration how to define a "foreign" function
implemented in C */
scheme_define(&sc,sc.global_env,mk_symbol(&sc,"func1"),mk_foreign_func(&sc, func1));
puts("Tiny Scheme REPL:");
puts("try e.g. the following commands:");
puts(" (write (+ 1 2))");
puts(" (func1 \"hello\" 42 1.24)\n");
do {
printf("\n>");
fgets( cmd_str, 80, stdin );
strip_cr( cmd_str, 80 );
if (strncmp(cmd_str,"(quit)",6)==0) break;
scheme_load_string( &sc, cmd_str );
} while(1);
scheme_deinit(&sc);
return 0;
}
Output
jrs@laptop:~/tinyscheme/tinyscheme-1.41$ ./testscm
Tiny Scheme REPL:
try e.g. the following commands:
(write (+ 1 2))
(func1 "hello" 42 1.24)
>(write (+ 1 2))
3
>(func1 "hello" 42 1.24)
argument 1 is string hello
argument 2 is integer number 42
argument 3 is real number 1.240000
>(quit)
jrs@laptop:~/tinyscheme/tinyscheme-1.41$
