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mirror of https://github.com/janet-lang/janet synced 2024-11-17 14:14:49 +00:00
janet/src/webclient/main.c
2018-10-16 23:08:26 -04:00

117 lines
3.5 KiB
C

/*
* Copyright (c) 2018 Calvin Rose
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <janet/janet.h>
#include <generated/webinit.h>
#include <emscripten.h>
static JanetFiber *repl_fiber = NULL;
static JanetBuffer *line_buffer = NULL;
static const uint8_t *line_prompt = NULL;
/* Yield to JS event loop from janet. Takes a repl prompt
* and a buffer to fill with input data. */
static int repl_yield(JanetArgs args) {
JANET_FIXARITY(args, 2);
JANET_ARG_STRING(line_prompt, args, 0);
JANET_ARG_BUFFER(line_buffer, args, 1);
/* Suspend janet repl by throwing a user defined signal */
return JANET_SIGNAL_USER9;
}
/* Re-enter the loop */
static int enter_loop(void) {
Janet ret;
JanetSignal status = janet_continue(repl_fiber, janet_wrap_nil(), &ret);
if (status == JANET_SIGNAL_ERROR) {
janet_stacktrace(repl_fiber, "runtime", ret);
janet_deinit();
repl_fiber = NULL;
return 1;
}
return 0;
}
/* Intialize the repl */
EMSCRIPTEN_KEEPALIVE
void repl_init(void) {
int status;
JanetTable *env;
/* Set up VM */
janet_init();
env = janet_core_env();
/* Janet line getter */
janet_def(env, "repl-yield", janet_wrap_cfunction(repl_yield));
janet_register("repl-yield", janet_wrap_cfunction(repl_yield));
/* Run startup script */
Janet ret;
status = janet_dobytes(env, janet_gen_webinit, sizeof(janet_gen_webinit), "webinit.janet", &ret);
if (status == JANET_SIGNAL_ERROR) {
printf("start up error.\n");
janet_deinit();
repl_fiber = NULL;
return;
}
janet_gcroot(ret);
repl_fiber = janet_unwrap_fiber(ret);
/* Start repl */
if (enter_loop()) return;
}
/* Deinitialize the repl */
EMSCRIPTEN_KEEPALIVE
void repl_deinit(void) {
if (!repl_fiber) {
return;
}
repl_fiber = NULL;
line_buffer = NULL;
janet_deinit();
}
/* Get the prompt to show in the repl */
EMSCRIPTEN_KEEPALIVE
const char *repl_prompt(void) {
return line_prompt ? ((const char *)line_prompt) : "";
}
/* Restart the repl calling from JS. Pass in the input for the next line. */
EMSCRIPTEN_KEEPALIVE
void repl_input(char *input) {
/* Create the repl if we haven't yet */
if (!repl_fiber) {
printf("initialize the repl first");
}
/* Now fill the pending line_buffer and resume the repl loop */
if (line_buffer) {
janet_buffer_push_cstring(line_buffer, input);
line_buffer = NULL;
enter_loop();
}
}