v/compiler/jsgen.v

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// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module main
// TODO replace with comptime code generation.
// TODO remove cJSON dependency.
// OLD: User decode_User(string js) {
// now it's
// User decode_User(cJSON* root) {
// User res;
// res.name = decode_string(js_get(root, "name"));
// res.profile = decode_Profile(js_get(root, "profile"));
// return res;
// }
// Codegen json_decode/encode funcs
fn (p mut Parser) gen_json_for_type(typ Type) {
mut dec := ''
mut enc := ''
t := typ.name
if t == 'int' || t == 'string' || t == 'bool' {
return
}
if p.first_run() {
return
}
// println('gen_json_for_type( $typ.name )')
// Register decoder fn
mut dec_fn := Fn {
pkg: p.pkg
typ: 'Option_$typ.name'
name: js_dec_name(t)
}
// Already registered? Skip.
if p.table.known_fn(dec_fn.name) {
return
}
// decode_TYPE funcs receive an actual cJSON* object to decode
// cJSON_Parse(str) call is added by the compiler
arg := Var {
typ: 'cJSON*'
}
dec_fn.args << arg
p.table.register_fn(dec_fn)
// Register encoder fn
mut enc_fn := Fn {
pkg: p.pkg
typ: 'cJSON*'
name: js_enc_name(t)
}
// encode_TYPE funcs receive an object to encode
enc_arg := Var {
typ: t
}
enc_fn.args << enc_arg
p.table.register_fn(enc_fn)
// Code gen decoder
dec += '
//$t $dec_fn.name(cJSON* root) {
Option $dec_fn.name(cJSON* root, $t* res) {
// $t res;
if (!root) {
const char *error_ptr = cJSON_GetErrorPtr();
if (error_ptr != NULL) {
fprintf(stderr, "Error in decode() for $t error_ptr=: %%s\\n", error_ptr);
// printf("\\nbad js=%%s\\n", js.str);
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return v_error(tos2(error_ptr));
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}
}
'
// Code gen encoder
enc += '
cJSON* $enc_fn.name($t val) {
cJSON *o = cJSON_CreateObject();
string res = tos2("");
'
// Handle arrays
if t.starts_with('array_') {
dec += p.decode_array(t)
enc += p.encode_array(t)
}
// Range through fields
for field in typ.fields {
if field.attr == 'skip' {
continue
}
field_type := p.table.find_type(field.typ)
// Now generate decoders for all field types in this struct
// need to do it here so that these functions are generated first
p.gen_json_for_type(field_type)
name := field.name
_typ := field.typ.replace('*', '')
enc_name := js_enc_name(_typ)
dec_name := js_dec_name(_typ)
if is_js_prim(_typ) {
dec += ' /*prim*/ res->$name = $dec_name(js_get(root, "$field.name"))'
// dec += '.data'
}
else {
dec += ' /*!!*/ $dec_name(js_get(root, "$field.name"), & (res->$name))'
}
dec += ';\n'
enc += ' cJSON_AddItemToObject(o, "$name", $enc_name(val.$name)); \n'
}
// cJSON_delete
p.cgen.fns << '$dec return opt_ok(res); \n}'
p.cgen.fns << '/*enc start*/ $enc return o;}'
}
fn is_js_prim(typ string) bool {
return typ == 'int' || typ == 'string' || typ == 'bool'
}
fn (p mut Parser) decode_array(typ string) string {
typ = typ.replace('array_', '')
t := p.table.find_type(typ)
fn_name := js_dec_name(typ)
// If we have `[]Profile`, have to register a Profile en(de)coder first
p.gen_json_for_type(t)
mut s := ''
if is_js_prim(typ) {
s = '$typ val= $fn_name(jsval); '
}
else {
s = ' $typ val; $fn_name(jsval, &val); '
}
return '
*res = new_array(0, 0, sizeof($typ));
const cJSON *jsval = NULL;
cJSON_ArrayForEach(jsval, root)
{
$s
array__push(res, &val);
}
'
}
fn js_enc_name(typ string) string {
name := 'json__jsencode_$typ'
return name
}
fn js_dec_name(typ string) string {
name := 'json__jsdecode_$typ'
return name
}
fn (p &Parser) encode_array(typ string) string {
typ = typ.replace('array_', '')
fn_name := js_enc_name(typ)
return '
o = cJSON_CreateArray();
for (int i = 0; i < val.len; i++){
cJSON_AddItemToArray(o, $fn_name( (($typ*)val.data)[i] ));
}
'
}