106 lines
1.9 KiB
V
106 lines
1.9 KiB
V
// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
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// Use of this source code is governed by an MIT license
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// that can be found in the LICENSE file.
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module builtin
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/*
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struct Option2<T> {
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ok bool
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is_none bool
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error string
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ecode int
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data T
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}
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*/
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struct OptionBase {
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ok bool
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is_none bool
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error string
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ecode int
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// Data is trailing after ecode
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// and is not included in here but in the
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// derived Option_xxx types
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}
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pub fn (o OptionBase) str() string {
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if o.ok && !o.is_none {
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return 'Option{ valid }'
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}
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if o.is_none {
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return 'Option{ none }'
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}
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return 'Option{ error: "${o.error}" }'
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}
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// `fn foo() ?Foo { return foo }` => `fn foo() ?Foo { return opt_ok(foo); }`
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fn opt_ok2(data voidptr, mut option &OptionBase, size int) {
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unsafe {
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*option = OptionBase {
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ok: true
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}
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// use ecode to get the end of OptionBase and then memcpy into it
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C.memcpy(byteptr(&option.ecode) + sizeof(int), data, size)
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}
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}
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// Old option type used for bootstrapping
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struct Option {
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ok bool
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is_none bool
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error string
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ecode int
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data [400]byte
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}
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pub fn (o Option) str() string {
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if o.ok && !o.is_none {
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return 'Option{ data: ' + o.data[0..32].hex() + ' }'
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}
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if o.is_none {
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return 'Option{ none }'
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}
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return 'Option{ error: "${o.error}" }'
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}
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// `fn foo() ?Foo { return foo }` => `fn foo() ?Foo { return opt_ok(foo); }`
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fn opt_ok(data voidptr, size int) Option {
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if size >= 400 {
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panic('option size too big: $size (max is 400), this is a temporary limit')
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}
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res := Option{
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ok: true
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}
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unsafe {
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C.memcpy(res.data, data, size)
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}
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return res
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}
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// used internally when returning `none`
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fn opt_none() Option {
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return Option{
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ok: false
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is_none: true
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}
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}
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pub fn error(s string) Option {
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return Option{
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ok: false
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is_none: false
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error: s
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}
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}
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pub fn error_with_code(s string, code int) Option {
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return Option{
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ok: false
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is_none: false
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error: s
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ecode: code
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}
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}
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