Crate ra_ap_hir

HIR (previously known as descriptors) provides a high-level object oriented access to Rust code.

The principal difference between HIR and syntax trees is that HIR is bound to a particular crate instance. That is, it has cfg flags and features applied. So, the relation between syntax and HIR is many-to-one.

HIR is the public API of the all of the compiler logic above syntax trees. It is written in “OO” style. Each type is self contained (as in, it knows it’s parents and full context). It should be “clean code”.

hir_* crates are the implementation of the compiler logic. They are written in “ECS” style, with relatively little abstractions. Many types are not self-contained, and explicitly use local indexes, arenas, etc.

hir is what insulates the “we don’t know how to actually write an incremental compiler” from the ide with completions, hovers, etc. It is a (soft, internal) boundary: https://www.tedinski.com/2018/02/06/system-boundaries.html.

Re-exports

pub use crate::diagnostics::AnyDiagnostic;
pub use crate::diagnostics::BreakOutsideOfLoop;
pub use crate::diagnostics::InactiveCode;
pub use crate::diagnostics::MacroError;
pub use crate::diagnostics::MismatchedArgCount;
pub use crate::diagnostics::MissingFields;
pub use crate::diagnostics::MissingMatchArms;
pub use crate::diagnostics::MissingOkOrSomeInTailExpr;
pub use crate::diagnostics::MissingUnsafe;
pub use crate::diagnostics::NoSuchField;
pub use crate::diagnostics::RemoveThisSemicolon;
pub use crate::diagnostics::ReplaceFilterMapNextWithFindMap;
pub use crate::diagnostics::UnimplementedBuiltinMacro;
pub use crate::diagnostics::UnresolvedExternCrate;
pub use crate::diagnostics::UnresolvedImport;
pub use crate::diagnostics::UnresolvedMacroCall;
pub use crate::diagnostics::UnresolvedModule;
pub use crate::diagnostics::UnresolvedProcMacro;

Modules

db	Re-exports various subcrates databases so that the calling code can depend only on hir. This breaks abstraction boundary a bit, it would be cool if we didn’t do that.
diagnostics	Re-export diagnostics such that clients of hir don’t have to depend on low-level crates.
import_map	A map of all publicly exported items in a crate.
known

Structs

Attr
Attrs
AttrsWithOwner
BuiltinType
Callable
CfgOptions	Configuration options used for conditional compilation on items with cfg attributes. We have two kind of options in different namespaces: atomic options like unix, and key-value options like target_arch="x86".
Const
ConstParam
Crate	hir::Crate describes a single crate. It’s the main interface with which a crate’s dependencies interact. Mostly, it should be just a proxy for the root module.
CrateDependency
Documentation	Holds documentation
Enum
ExpandResult
ExprScopes
Field
Function
HirFileId	Input to the analyzer is a set of files, where each file is identified by FileId and contains source code. However, another source of source code in Rust are macros: each macro can be thought of as producing a “temporary file”. To assign an id to such a file, we use the id of the macro call that produced the file. So, a HirFileId is either a FileId (source code written by user), or a MacroCallId (source code produced by macro).
Impl
InFile	InFile<T> stores a value of T inside a particular file/syntax tree.
IncorrectCase
Label
LifetimeParam
Local
MacroCallId	MacroCallId identifies a particular macro invocation, like println!("Hello, {}", world).
MacroCallLoc
MacroDef
MacroDefId
MacroFile
ModPath
Module
Name	Name is a wrapper around string, which is used in hir for both references and declarations. In theory, names should also carry hygiene info, but we are not there yet!
Param
SelfParam
Semantics	Primary API to get semantic information, like types, from syntax trees.
SemanticsScope	SemanticScope encapsulates the notion of a scope (the set of visible names) at a particular program point.
Static
Struct
Trait
Type
TypeAlias
TypeParam
Union
Variant

Enums

Access
Adt	A Data Type
AssocItem	Invariant: inner.as_assoc_item(db).is_some() We do not actively enforce this invariant.
AssocItemContainer
CallableKind
CfgAtom	A simple configuration value passed in from the outside.
CfgExpr
DefWithBody	The defs which have a body.
FieldSource
GenericDef
GenericParam
ItemInNs
MacroKind
ModuleDef	The defs which can be visible in the module.
ModuleSource
Mutability
Namespace
Origin
PathKind
PathResolution
PrefixKind
ScopeDef	For IDE only
StructKind
TypeRef	Compare ty::Ty
VariantDef
Visibility	Visibility of an item, with the path resolved.

Traits

AsAssocItem
HasAttrs
HasSource
HasVisibility
HirDisplay