akbasic/src/main.c

/**
 * @file main.c
 * @brief The standalone driver.
 *
 * Everything that belongs to a program rather than to a library lives here: argv
 * handling, sink selection, the unbounded run loop, and a FINISH_NORETURN --
 * which belongs only in a main(). The interpreter library itself never
 * terminates the process.
 *
 * The runtime is static rather than automatic because it carries every pool the
 * interpreter owns -- several megabytes -- and that will not fit on a default
 * stack. An embedding game would place it in its own state for the same reason.
 */

#include <stdio.h>
#include <stdlib.h>

#include <akerror.h>
#include <akstdlib.h>

#include <akbasic/error.h>
#include <akbasic/runtime.h>
#include <akbasic/sink.h>

static akbasic_Runtime RUNTIME;
static akbasic_TextSink SINK;
static akbasic_StdioSink SINKSTATE;

int main(int argc, char **argv)
{
    PREPARE_ERROR(errctx);
    FILE *program = NULL;
    int rc = EXIT_SUCCESS;

    ATTEMPT {
	if ( argc > 1 ) {
	    /*
	     * A file argument: read the program from it in RUNSTREAM mode, which
	     * files each line under its line number and then switches to RUN.
	     */
	    CATCH(errctx, aksl_fopen(argv[1], "r", &program));
	    CATCH(errctx, akbasic_sink_init_stdio(&SINK, &SINKSTATE, stdout, program));
	    CATCH(errctx, akbasic_runtime_init(&RUNTIME, &SINK));
	    CATCH(errctx, akbasic_runtime_start(&RUNTIME, AKBASIC_MODE_RUNSTREAM));
	} else {
	    CATCH(errctx, akbasic_sink_init_stdio(&SINK, &SINKSTATE, stdout, stdin));
	    CATCH(errctx, akbasic_runtime_init(&RUNTIME, &SINK));
	    CATCH(errctx, akbasic_runtime_start(&RUNTIME, AKBASIC_MODE_REPL));
	}
	/* Unbounded: this is the driver, and it has nothing else to do. */
	CATCH(errctx, akbasic_runtime_run(&RUNTIME, 0));
    } CLEANUP {
	if ( program != NULL ) {
	    IGNORE(aksl_fclose(program));
	}
    } PROCESS(errctx) {
    } HANDLE_DEFAULT(errctx) {
	LOG_ERROR_WITH_MESSAGE(errctx, "akbasic terminated on an unhandled error");
	rc = EXIT_FAILURE;
    } FINISH_NORETURN(errctx);

    return rc;
}