jinx-mod.c

/* Jinx bindings to libenchant

Copyright (C) 2023-2024 Free Software Foundation, Inc.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */

#include <emacs-module.h>
#include <enchant.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define jinx_unused(var) _##var __attribute__((unused))
#define jinx_autofree    __attribute__((cleanup(jinx_autofree_cleanup)))

int plugin_is_GPL_compatible;

static EnchantBroker* broker = 0;
static emacs_value Qt, Qnil, Qcons;

static EnchantBroker* jinx_broker(void) {
    return broker ? broker : (broker = enchant_broker_init());
}

static void jinx_autofree_cleanup(char **p) {
    free(*(void**)p);
}

static emacs_value jinx_str(emacs_env* env, const char* str) {
    return env->make_string(env, str, strlen(str));
}

static emacs_value jinx_cons(emacs_env* env, emacs_value a, emacs_value b) {
    return env->funcall(env, Qcons, 2, (emacs_value[]){a, b});
}

static char* jinx_cstr(emacs_env* env, emacs_value val) {
    ptrdiff_t size = 0;
    if (!env->copy_string_contents(env, val, 0, &size))
        return 0;
    char* str = malloc(size);
    if (!str) {
        env->non_local_exit_signal(env,
                                   env->intern(env, "memory-full"),
                                   Qnil);
        return 0;
    }
    if (!env->copy_string_contents(env, val, str, &size)) {
        free(str);
        return 0;
    }
    return str;
}

static void jinx_defun(emacs_env* env, const char* name,
                       ptrdiff_t min, ptrdiff_t max, void* fun) {
    env->funcall(env, env->intern(env, "defalias"), 2,
                 (emacs_value[]){
                     env->intern(env, name),
                     env->make_function(env, min, max, fun, 0, 0)
                 });
}

static void jinx_free_dict(void* dict) {
    enchant_broker_free_dict(broker, dict);
}

static emacs_value jinx_dict(emacs_env* env, ptrdiff_t jinx_unused(nargs),
                             emacs_value args[], void* jinx_unused(data)) {
    jinx_autofree char* str = jinx_cstr(env, args[0]);
    EnchantDict* dict =
        str ? enchant_broker_request_dict(jinx_broker(), str) : 0;
    return dict
        ? env->make_user_ptr(env, jinx_free_dict, dict)
        : Qnil;
}

static void jinx_describe_cb(const char* const lang_tag,
                             const char* const provider_name,
                             const char* const jinx_unused(provider_desc),
                             const char* const jinx_unused(provider_file),
                             void* data) {
    emacs_env* env = ((emacs_env**)data)[0];
    ((emacs_value*)data)[1] = jinx_cons(env,
                                        jinx_str(env, lang_tag),
                                        jinx_str(env, provider_name));
}

static emacs_value jinx_describe(emacs_env* env, ptrdiff_t jinx_unused(nargs),
                                 emacs_value args[], void* jinx_unused(data)) {
    EnchantDict* dict = env->get_user_ptr(env, args[0]);
    if (!dict)
        return Qnil;
    void* data[] = { env, 0 };
    enchant_dict_describe(dict, jinx_describe_cb, data);
    return data[1];
}

static void jinx_langs_cb(const char* const lang_tag,
                          const char* const jinx_unused(provider_name),
                          const char* const jinx_unused(provider_desc),
                          const char* const jinx_unused(provider_file),
                          void* data) {
    emacs_env* env = ((emacs_env**)data)[0];
    ((emacs_value*)data)[1] = jinx_cons(env,
                                        jinx_str(env, lang_tag),
                                        ((emacs_value*)data)[1]);
}

static emacs_value jinx_langs(emacs_env* env, ptrdiff_t jinx_unused(nargs),
                              emacs_value jinx_unused(args[]),
                              void* jinx_unused(data)) {
    void* data[] = { env, Qnil };
    enchant_broker_list_dicts(jinx_broker(), jinx_langs_cb, data);
    return data[1];
}

static emacs_value jinx_check(emacs_env* env, ptrdiff_t jinx_unused(nargs),
                              emacs_value args[], void* jinx_unused(data)) {
    EnchantDict* dict = env->get_user_ptr(env, args[0]);
    jinx_autofree char* str = jinx_cstr(env, args[1]);
    // Do not error in the checking function (Non-Unicode strings)
    env->non_local_exit_clear(env);
    return !dict || !str || enchant_dict_check(dict, str, -1) ? Qnil : Qt;
}

static emacs_value jinx_add(emacs_env* env, ptrdiff_t jinx_unused(nargs),
                            emacs_value args[], void* jinx_unused(data)) {
    EnchantDict* dict = env->get_user_ptr(env, args[0]);
    jinx_autofree char* str = jinx_cstr(env, args[1]);
    if (dict && str)
        enchant_dict_add(dict, str, -1);
    return Qnil;
}

static emacs_value jinx_wordchars(emacs_env* env, ptrdiff_t jinx_unused(nargs),
                                  emacs_value args[], void* jinx_unused(data)) {
    EnchantDict* dict = env->get_user_ptr(env, args[0]);
    if (dict) {
        // Enchant older than 2.3.1 sometimes does not return UTF-8
        // See https://github.com/AbiWord/enchant/blob/master/NEWS
        emacs_value str = jinx_str(env, enchant_dict_get_extra_word_characters(dict));
        if (env->non_local_exit_check(env) == emacs_funcall_exit_return)
            return str;
        env->non_local_exit_clear(env);
    }
    return Qnil;
}

static emacs_value jinx_suggest(emacs_env* env, ptrdiff_t jinx_unused(nargs),
                                emacs_value args[], void* jinx_unused(data)) {
    EnchantDict* dict = env->get_user_ptr(env, args[0]);
    jinx_autofree char* str = jinx_cstr(env, args[1]);
    emacs_value list = Qnil;
    size_t count = 0;
    char** suggs = str && dict ? enchant_dict_suggest(dict, str, -1, &count) : 0;
    if (suggs) {
        while (count > 0)
            list = jinx_cons(env, jinx_str(env, suggs[--count]), list);
        enchant_dict_free_string_list(dict, suggs);
    }
    return list;
}

int emacs_module_init(struct emacs_runtime *runtime) {
    if ((size_t)runtime->size < sizeof (*runtime))
        return 1; // Require Emacs binary compatibility
    emacs_env* env = runtime->get_environment(runtime);
    if ((size_t)env->size < sizeof (*env))
        return 2; // Require Emacs binary compatibility
    int v0, v1, v2;
    if (sscanf(enchant_get_version(), "%d.%d.%d", &v0, &v1, &v2) != 3 ||
        v0 * 10000 + v1 * 100 + v2 < 20301)
        env->funcall(env, env->intern(env, "message"), 1,
                     (emacs_value[]){
                         jinx_str(env, "Jinx recommends Enchant 2.3.1 or newer")
                     });
    Qt = env->make_global_ref(env, env->intern(env, "t"));
    Qnil = env->make_global_ref(env, env->intern(env, "nil"));
    Qcons = env->make_global_ref(env, env->intern(env, "cons"));
    jinx_defun(env, "jinx--mod-suggest", 2, 2, jinx_suggest);
    jinx_defun(env, "jinx--mod-check", 2, 2, jinx_check);
    jinx_defun(env, "jinx--mod-add", 2, 2, jinx_add);
    jinx_defun(env, "jinx--mod-dict", 1, 1, jinx_dict);
    jinx_defun(env, "jinx--mod-langs", 0, 0, jinx_langs);
    jinx_defun(env, "jinx--mod-describe", 1, 1, jinx_describe);
    jinx_defun(env, "jinx--mod-wordchars", 1, 1, jinx_wordchars);
    return 0;
}