js: initial support for optional return unwrapping (#6926)

pull/6937/head
pancake 2020-11-24 12:54:26 +01:00 committed by GitHub
parent 789912238f
commit aa90625819
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 54 additions and 1 deletions

View File

@ -37,7 +37,52 @@ pub fn exit(c int) {
JS.process.exit(c)
}
pub fn unwrap(opt any) any {
o := &Option(opt)
if o.not_ok {
panic(o.error)
return o.error
}
return opt
}
pub fn panic(s string) {
eprintln('V panic: $s')
exit(1)
}
struct Option {
not_ok bool
is_none bool
error string
ecode int
data any
}
pub fn (o Option) str() string {
if !o.not_ok {
return 'Option{ ok }'
}
if o.is_none {
return 'Option{ none }'
}
return 'Option{ error: "${o.error}" }'
}
pub fn error(s string) Option {
return Option{
not_ok: true
is_none: false
error: s
}
}
pub fn error_with_code(s string, code int) Option {
return Option{
not_ok: true
is_none: false
error: s
ecode: code
}
}

View File

@ -1175,6 +1175,10 @@ fn (mut g JsGen) gen_call_expr(it ast.CallExpr) {
} else {
name = g.js_name(it.name)
}
call_return_is_optional := it.return_type.has_flag(.optional)
if call_return_is_optional {
g.write('builtin.unwrap(')
}
g.expr(it.left)
if it.is_method { // foo.bar.baz()
sym := g.table.get_type_symbol(it.receiver_type)
@ -1224,8 +1228,12 @@ fn (mut g JsGen) gen_call_expr(it ast.CallExpr) {
g.write(', ')
}
}
if call_return_is_optional {
g.write('))')
} else {
g.write(')')
}
}
fn (mut g JsGen) gen_ident(node ast.Ident) {
mut name := g.js_name(node.name)