mirror/v
1
0
Fork 0
mirror of https://github.com/vlang/v.git synced 2023-08-10 21:13:21 +03:00
Code Issues Projects Releases Wiki Activity

array: optimized generic filter()

Browse Source
This commit is contained in:
Alexander Medvednikov
2019-10-17 10:44:20 +03:00
parent eda0c73bef
commit 80e79a3966
6 changed files with 67 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
vlib/compiler/parser.v
View File

@@ -2104,6 +2104,50 @@ fn (p mut Parser) dot(str_typ_ string, method_ph int) string {
return 'void'
}
field_name := p.lit
if field_name == 'filter' && str_typ.starts_with('array_') {
/*
// V
a := [1,2,3,4]
b := a.filter(it % 2 == 0)
// C
array_int a = ...;
array_int tmp2 = new_array(0, 4, 4);
for (int i = 0; i < a.len; i++) {
int it = ((int*)a.data)[i];
if (it % 2 == 0) array_push(&tmp2, &it);
}
array_int b = tmp2;
*/
val_type:=str_typ.right(6)
p.open_scope()
p.register_var(Var{
name: 'it'
typ: val_type
})
p.next()
p.check(.lpar)
p.cgen.resetln('')
tmp := p.get_tmp()
a := p.expr_var.name
p.cgen.set_placeholder(method_ph,'\n$str_typ $tmp = new_array(0, $a .len,sizeof($val_type));\n')
p.genln('for (int i = 0; i < ${a}.len; i++) {')
p.genln('$val_type it = (($val_type*)${a}.data)[i];')
if val_type == 'string'{
p.genln('println(it);')
}
p.gen('if (')
p.bool_expression()
p.genln(') array_push(&$tmp, &it);')
//p.genln(') array_push(&$tmp, &((($val_type*)${a}.data)[i]));')
//p.genln(') array_push(&$tmp, ${a}.data + i * ${a}.element_size);')
p.genln('}')
p.gen(tmp) // TODO why does this `gen()` work?
p.check(.rpar)
p.close_scope()
return str_typ
}
fname_tidx := p.cur_tok_index()
p.fgen(field_name)
//p.log('dot() field_name=$field_name typ=$str_typ')