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Calvin bd4d5805dd Replace addr with ref in design docs (#6141 )

Updates the documentation under `docs/design/` to use `ref` instead of
`addr` after their removal in #5434. Care was taken to manually clean up
edge cases and, in a couple cases, surrounding text (see
3d72c49bb75c0f40ca7e8114b6a1369b941e1697). After this change, there are
no matches for `addr(?!ess)` in `docs/design/`.

Closes #6032

2025-10-06 18:44:24 +00:00

4.3 KiB

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Words

Overview
Keywords
Alternatives considered
References

Overview

A word is a lexical element formed from a sequence of letters or letter-like characters, such as fn or Foo or Int, optionally preceded by r#.

The exact lexical form of words has not yet been settled. However, Carbon will follow lexical conventions for identifiers based on Unicode Annex #31. TODO: Update this once the precise rules are decided; see the Unicode source files proposal.

Carbon source files, including comments and string literals, are required to be in Unicode Normalization Form C (NFC).

Keywords

The following words are interpreted as keywords:

abstract
adapt
alias
and
as
auto
base
break
Core
case
choice
class
constraint
continue
default
destroy
else
export
extend
final
fn
for
forall
friend
if
impl
impls
import
in
interface
let
library
like
match
namespace
not
observe
or
override
package
partial
private
protected
ref
require
return
returned
Self
self
template
then
type
var
virtual
where
while

Type literals

A word starting with i, u, or f, followed by a decimal integer, is a numeric type literal.

Identifiers

A word is interpreted as an identifier if it is neither a keyword nor a type literal.

Raw identifiers

A raw identifier is a word starting with r#. A raw identifier is equivalent to the word following the r# prefix, except that it is always interpreted as an identifier, even if it would otherwise be a keyword or type literal.

Raw identifiers can be used to specify identifiers which have the same spelling as keywords; for example, r#impl. This can be useful when interoperating with C++ code that uses identifiers that are keywords in Carbon, and when migrating between versions of Carbon.

The word doesn't need to be a keyword, in order to support forwards compatibility when a keyword is planned to be added. If word is an identifier, then word and r#word have the same meaning.

Alternatives considered

Overview:

Type literals:

Raw identifiers:

References

Proposal #142: Unicode source files
Proposal #2015: Numeric type literal syntax
Proposal #3797: Raw identifier syntax

4.3 KiB Raw Blame History