s7 wasm example

s7_wasm.c

#include "s7.h"

#include <stdio.h>

void _s7_print_stderr(s7_scheme *sc, uint8_t c, s7_pointer port) {
    printf("%c", c);
}

int main() {
  printf("hello, world!\n");
  s7_scheme* sc = s7_init();
  s7_set_current_output_port(sc, s7_open_output_function(sc, _s7_print_stderr));
  s7_eval_c_string(sc, "(format #t \"result is ~A\n\" (+ 1 2 3))");
  return 0;
}

Or, the "fix" for popen (or throw some error actually)

 static s7_pointer g_system(s7_scheme *sc, s7_pointer args)
 {
   #define H_system "(system command) executes the command.  If the optional second argument is #t, \
 system captures the output as a string and returns it."
   #define Q_system s7_make_signature(sc, 3, s7_make_signature(sc, 2, sc->is_integer_symbol, sc->is_string_symbol), sc->is_string_symbol, sc->is_boolean_symbol)
 
+#ifdef __EMSCRIPTEN__
+     return s7_nil(sc);
+#else

Fantastic! Can't wait to try. :-)