builtin: extract vlib/builtin/result.v from vlib/builtin/option.v

vlib/builtin/option.v

@@ -3,110 +3,6 @@
 // that can be found in the LICENSE file.
 module builtin
 
-// IError holds information about an error instance
-pub interface IError {
-	// >> Hack to allow old style custom error implementations
-	// TODO: remove once deprecation period for `IError` methods has ended
-	msg string
-	code int // <<
-	msg() string
-	code() int
-}
-
-// str returns the message of IError
-pub fn (err IError) str() string {
-	return match err {
-		None__ {
-			'none'
-		}
-		Error {
-			err.msg()
-		}
-		MessageError {
-			err.msg()
-		}
-		else {
-			// >> Hack to allow old style custom error implementations
-			// TODO: remove once deprecation period for `IError` methods has ended
-			// old_error_style := unsafe { voidptr(&err.msg) != voidptr(&err.code) } // if fields are not defined (new style) they don't have an offset between
-			// <<
-			'${err.type_name()}: ${err.msg()}'
-		}
-	}
-}
-
-// Error is the empty default implementation of `IError`.
-pub struct Error {}
-
-pub fn (err Error) msg() string {
-	return ''
-}
-
-pub fn (err Error) code() int {
-	return 0
-}
-
-// MessageError is the default implementation of the `IError` interface that is returned by the `error()` function
-struct MessageError {
-pub:
-	msg  string
-	code int
-}
-
-// msg returns the message of MessageError
-pub fn (err MessageError) msg() string {
-	if err.code > 0 {
-		return '${err.msg}; code: ${err.code}'
-	}
-	return err.msg
-}
-
-// code returns the code of MessageError
-pub fn (err MessageError) code() int {
-	return err.code
-}
-
-[unsafe]
-pub fn (err &MessageError) free() {
-	unsafe { err.msg.free() }
-}
-
-const none__ = IError(&None__{})
-
-struct None__ {
-	Error
-}
-
-fn (_ None__) str() string {
-	return 'none'
-}
-
-[if trace_error ?]
-fn trace_error(x string) {
-	eprintln('> ${@FN} | ${x}')
-}
-
-// error returns a default error instance containing the error given in `message`.
-// Example: if ouch { return error('an error occurred') }
-[inline]
-pub fn error(message string) IError {
-	trace_error(message)
-	return &MessageError{
-		msg: message
-	}
-}
-
-// error_with_code returns a default error instance containing the given `message` and error `code`.
-// Example: if ouch { return error_with_code('an error occurred', 1) }
-[inline]
-pub fn error_with_code(message string, code int) IError {
-	trace_error('${message} | code: ${code}')
-	return &MessageError{
-		msg: message
-		code: code
-	}
-}
-
 // Option is the base of V's internal option return system.
 struct Option {
 	state u8
@@ -125,6 +21,7 @@ struct _option {
 	// derived _option_xxx types
 }
 
+[markused]
 fn _option_none(data voidptr, mut option _option, size int) {
 	unsafe {
 		*option = _option{
@@ -135,6 +32,7 @@ fn _option_none(data voidptr, mut option _option, size int) {
 	}
 }
 
+[markused]
 fn _option_ok(data voidptr, mut option _option, size int) {
 	unsafe {
 		*option = _option{}
@@ -143,20 +41,16 @@ fn _option_ok(data voidptr, mut option _option, size int) {
 	}
 }
 
-struct _result {
-	is_error bool
-	err      IError = none__
-	// Data is trailing after err
-	// and is not included in here but in the
-	// derived Result_xxx types
+//
+
+const none__ = IError(&None__{})
+
+struct None__ {
+	Error
 }
 
-fn _result_ok(data voidptr, mut res _result, size int) {
-	unsafe {
-		*res = _result{}
-		// use err to get the end of ResultBase and then memcpy into it
-		vmemcpy(&u8(&res.err) + sizeof(IError), data, size)
-	}
+fn (_ None__) str() string {
+	return 'none'
 }
 
 pub fn (_ none) str() string {

vlib/builtin/result.v

@@ -0,0 +1,115 @@
+// Copyright (c) 2019-2023 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 builtin
+
+// IError holds information about an error instance
+pub interface IError {
+	// >> Hack to allow old style custom error implementations
+	// TODO: remove once deprecation period for `IError` methods has ended
+	msg string
+	code int // <<
+	msg() string
+	code() int
+}
+
+struct _result {
+	is_error bool
+	err      IError = none__
+	// Data is trailing after err
+	// and is not included in here but in the
+	// derived Result_xxx types
+}
+
+[markused]
+fn _result_ok(data voidptr, mut res _result, size int) {
+	unsafe {
+		*res = _result{}
+		// use err to get the end of ResultBase and then memcpy into it
+		vmemcpy(&u8(&res.err) + sizeof(IError), data, size)
+	}
+}
+
+// str returns the message of IError
+pub fn (err IError) str() string {
+	return match err {
+		None__ {
+			'none'
+		}
+		Error {
+			err.msg()
+		}
+		MessageError {
+			err.msg()
+		}
+		else {
+			// >> Hack to allow old style custom error implementations
+			// TODO: remove once deprecation period for `IError` methods has ended
+			// old_error_style := unsafe { voidptr(&err.msg) != voidptr(&err.code) } // if fields are not defined (new style) they don't have an offset between
+			// <<
+			'${err.type_name()}: ${err.msg()}'
+		}
+	}
+}
+
+// Error is the empty default implementation of `IError`.
+pub struct Error {}
+
+pub fn (err Error) msg() string {
+	return ''
+}
+
+pub fn (err Error) code() int {
+	return 0
+}
+
+// MessageError is the default implementation of the `IError` interface that is returned by the `error()` function
+struct MessageError {
+pub:
+	msg  string
+	code int
+}
+
+// msg returns the message of MessageError
+pub fn (err MessageError) msg() string {
+	if err.code > 0 {
+		return '${err.msg}; code: ${err.code}'
+	}
+	return err.msg
+}
+
+// code returns the code of MessageError
+pub fn (err MessageError) code() int {
+	return err.code
+}
+
+[unsafe]
+pub fn (err &MessageError) free() {
+	unsafe { err.msg.free() }
+}
+
+[if trace_error ?]
+fn trace_error(x string) {
+	eprintln('> ${@FN} | ${x}')
+}
+
+// error returns a default error instance containing the error given in `message`.
+// Example: if ouch { return error('an error occurred') }
+[inline]
+pub fn error(message string) IError {
+	trace_error(message)
+	return &MessageError{
+		msg: message
+	}
+}
+
+// error_with_code returns a default error instance containing the given `message` and error `code`.
+// Example: if ouch { return error_with_code('an error occurred', 1) }
+[inline]
+pub fn error_with_code(message string, code int) IError {
+	trace_error('${message} | code: ${code}')
+	return &MessageError{
+		msg: message
+		code: code
+	}
+}