diff --git a/src/SUMMARY.md b/src/SUMMARY.md index a06caa72f65fc..289f59e1f2e28 100644 --- a/src/SUMMARY.md +++ b/src/SUMMARY.md @@ -8,6 +8,7 @@ - [Lexical structure](lexical-structure.md) - [Input format](input-format.md) + - [Keywords](keywords.md) - [Identifiers](identifiers.md) - [Comments](comments.md) - [Whitespace](whitespace.md) diff --git a/src/keywords.md b/src/keywords.md new file mode 100644 index 0000000000000..bf743f6c42bde --- /dev/null +++ b/src/keywords.md @@ -0,0 +1,84 @@ +# Keywords + +Rust divides keywords in three categories: + - [strict](#strict-keywords) + - [weak](#weak-keywords) + - [reserved](#reserved-keywords) + +## Strict keywords + +These keywords can only be used in their correct contexts. For example, it is +not allowed to declare a variable with name `struct`. + +> **Lexer:** +> KW_AS : `as` +> KW_BOX : `box` +> KW_BREAK : `break` +> KW_CONST : `const` +> KW_CONTINUE : `continue` +> KW_CRATE : `crate` +> KW_ELSE : `else` +> KW_ENUM : `enum` +> KW_EXTERN : `extern` +> KW_FALSE : `false` +> KW_FN : `fn` +> KW_FOR : `for` +> KW_IF : `if` +> KW_IMPL : `impl` +> KW_IN : `in` +> KW_LET : `let` +> KW_LOOP : `loop` +> KW_MATCH : `match` +> KW_MOD : `mod` +> KW_MOVE : `move` +> KW_MUT : `mut` +> KW_PUB : `pub` +> KW_REF : `ref` +> KW_RETURN : `return` +> KW_SELFVALUE : `self` +> KW_SELFTYPE : `Self` +> KW_STATIC : `static` +> KW_STRUCT : `struct` +> KW_SUPER : `super` +> KW_TRAIT : `trait` +> KW_TRUE : `true` +> KW_TYPE : `type` +> KW_UNSAFE : `unsafe` +> KW_USE : `use` +> KW_WHERE : `wher` +> KW_WHILE : `while` + +## Weak keywords + +These keywords have special meaning only in certain contexts. For example, +it is possible to declare a variable or method with the name `union`. + +> **Lexer** +> KW_CATCH : `catch` +> KW_DEFAULT : `default` +> KW_UNION : `union` +> KW_STATICLIFETIME : `'static` + +## Reserved keywords + +These keywords aren't used yet, but they are reserved for future use. +The reasoning behind this is to make current programs forward compatible with +future versions of rust by forbiding them to use these keywords. + +> **Lexer** +> KW_ABSTRACT : `abstract` +> KW_ALIGNOF : `alignof` +> KW_BECOME : `become` +> KW_DO : `do` +> KW_FINAL : `final` +> KW_MACRO : `macro` +> KW_OFFSETOF : `offsetof` +> KW_OVERRIDE : `override` +> KW_PRIV : `priv` +> KW_PROC : `proc` +> KW_PURE : `pure` +> KW_SIZEOF : `sizeof` +> KW_TYPEOF : `typeof` +> KW_UNSIZED : `unsized` +> KW_VIRTUAL : `virtual` +> KW_YIELD : `yield`