projects / rustc.git / blame
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1 | # Glossary |
| 2 | ||
| 3 | ### Abstract Syntax Tree | |
| 4 | ||
| 5 | An ‘abstract syntax tree’, or ‘AST’, is an intermediate representation of | |
| 6 | the structure of the program when the compiler is compiling it. | |
| 7 | ||
| 8 | ### Arity | |
| 9 | ||
| 10 | Arity refers to the number of arguments a function or operation takes. | |
| 11 | For example, `(2, 3)` and `(4, 6)` have arity 2, and`(8, 2, 6)` has arity 3. | |
| 12 | ||
| 13 | ### Array | |
| 14 | ||
| 15 | An array, sometimes also called a fixed-size array or an inline array, is a value | |
| 16 | describing a collection of elements, each selected by an index that can be computed | |
| 17 | at run time by the program. It occupies a contiguous region of memory. | |
| 18 | ||
| 19 | ### Bound | |
| 20 | ||
| 21 | Bounds are constraints on a type or trait. For example, if a bound | |
| 22 | is placed on the argument a function takes, types passed to that function | |
| 23 | must abide by that constraint. | |
| 24 | ||
| 25 | ### Combinator | |
| 26 | ||
| 27 | Combinators are higher-order functions that apply only functions and | |
| 28 | earlier defined combinators to provide a result from its arguments. | |
| 29 | They can be used to manage control flow in a modular fashion. | |
| 30 | ||
| 31 | ### Dispatch | |
| 32 | ||
| 33 | Dispatch is the mechanism to determine which specific version of code is actually | |
| 34 | run when it involves polymorphism. Two major forms of dispatch are static dispatch and | |
| 35 | dynamic dispatch. While Rust favors static dispatch, it also supports dynamic dispatch | |
| 36 | through a mechanism called ‘trait objects’. | |
| 37 | ||
| 38 | ### Dynamically Sized Type | |
| 39 | ||
| 40 | A dynamically sized type (DST) is a type without a statically known size or alignment. | |
| 41 | ||
| 42 | ### Expression | |
| 43 | ||
| 44 | An expression is a combination of values, constants, variables, operators | |
| 45 | and functions that evaluate to a single value, with or without side-effects. | |
| 46 | ||
| 47 | For example, `2 + (3 * 4)` is an expression that returns the value 14. | |
| 48 | ||
| 49 | ### Prelude | |
| 50 | ||
| 51 | Prelude, or The Rust Prelude, is a small collection of items - mostly traits - that are | |
| 52 | imported into very module of every crate. The traits in the prelude are pervasive. | |
| 53 | ||
| 54 | ### Slice | |
| 55 | ||
| 56 | A slice is dynamically-sized view into a contiguous sequence, written as `[T]`. | |
| 57 | ||
| 58 | It is often seen in its borrowed forms, either mutable or shared. The shared | |
| 59 | slice type is `&[T]`, while the mutable slice type is `&mut [T]`, where `T` represents | |
| 60 | the element type. | |
| 61 | ||
| 62 | ### Statement | |
| 63 | ||
| 64 | A statement is the smallest standalone element of a programming language | |
| 65 | that commands a computer to perform an action. | |
| 66 | ||
| 67 | ### String literal | |
| 68 | ||
| 69 | A string literal is a string stored directly in the final binary, and so will be | |
| 70 | valid for the `'static` duration. | |
| 71 | ||
| 72 | Its type is `'static` duration borrowed string slice, `&'static str`. | |
| 73 | ||
| 74 | ### String slice | |
| 75 | ||
| 76 | A string slice is the most primitive string type in Rust, written as `str`. It is | |
| 77 | often seen in its borrowed forms, either mutable or shared. The shared | |
| 78 | string slice type is `&str`, while the mutable string slice type is `&mut str`. | |
| 79 | ||
| 80 | Strings slices are always valid UTF-8. | |
| 81 | ||
| 82 | ### Trait | |
| 83 | ||
| 84 | A trait is a language item that is used for describing the functionalities a type must provide. | |
| 85 | It allow a type to make certain promises about its behavior. | |
| 86 | ||
| 87 | Generic functions and generic structs can exploit traits to constrain, or bound, the types they accept. |