Crate rustdoc_types

Rustdoc’s JSON output interface

These types are the public API exposed through the --output-format json flag. The Crate struct is the root of the JSON blob and all other items are contained within.

We expose a rustc-hash feature that is disabled by default. This feature switches the std::collections::HashMap for [rustc_hash::FxHashMap] to improve the performance of said HashMap in specific situations.

cargo-semver-checks for example, saw a -3% improvement when benchmarking using the aws_sdk_ec2 JSON output (~500MB of JSON). As always, we recommend measuring the impact before turning this feature on, as FxHashMap only concerns itself with hash speed, and may increase the number of collisions.

Structs

• AssocItemConstraint
  Describes a bound applied to an associated type/constant.
• Constant
  A constant.
• Crate
  The root of the emitted JSON blob.
• Deprecation
  Information about the deprecation of an Item.
• Discriminant
  The value that distinguishes a variant in an Enum from other variants.
• DynTrait
  Dynamic trait object type (dyn Trait).
• Enum
  An enum.
• ExternalCrate
  Metadata of a crate, either the same crate on which rustdoc was invoked, or its dependency.
• Function
  A function declaration (including methods and other associated functions).
• FunctionHeader
  A set of fundamental properties of a function.
• FunctionPointer
  A type that is a function pointer.
• FunctionSignature
  The signature of a function.
• GenericParamDef
  One generic parameter accepted by an item.
• Generics
  Generic parameters accepted by an item and where clauses imposed on it and the parameters.
• Id
  An opaque identifier for an item.
• Impl
  An impl block.
• Item
  Anything that can hold documentation - modules, structs, enums, functions, traits, etc.
• ItemSummary
  Information about an external (not defined in the local crate) Item.
• Module
  A module declaration, e.g. mod foo; or mod foo {}.
• Path
  A type that has a simple path to it. This is the kind of type of structs, unions, enums, etc.
• PolyTrait
  A trait and potential HRTBs
• Primitive
  A primitive type declaration. Declarations of this kind can only come from the core library.
• ProcMacro
  A procedural macro.
• Span
  A range of source code.
• Static
  A static declaration.
• Struct
  A struct.
• Trait
  A trait declaration.
• TraitAlias
  A trait alias declaration, e.g. trait Int = Add + Sub + Mul + Div;
• TypeAlias
  A type alias declaration, e.g. type Pig = std::borrow::Cow<'static, str>;
• Union
  A union.
• Use
  A use statement.
• Variant
  A variant of an enum.

Enums

• Abi
  The ABI (Application Binary Interface) used by a function.
• AssocItemConstraintKind
  The way in which an associate type/constant is bound.
• GenericArg
  One argument in a list of generic arguments to a path segment.
• GenericArgs
  A set of generic arguments provided to a path segment, e.g.
• GenericBound
  Either a trait bound or a lifetime bound.
• GenericParamDefKind
  The kind of a GenericParamDef.
• ItemEnum
  Specific fields of an item.
• ItemKind
  The fundamental kind of an item. Unlike ItemEnum, this does not carry any additional info.
• MacroKind
  The way a ProcMacro is declared to be used.
• StructKind
  The kind of a Struct and the data specific to it, i.e. fields.
• Term
  Either a type or a constant, usually stored as the right-hand side of an equation in places like AssocItemConstraint
• TraitBoundModifier
  A set of modifiers applied to a trait.
• Type
  A type.
• VariantKind
  The kind of an Enum Variant and the data specific to it, i.e. fields.
• Visibility
  Visibility of an Item.
• WherePredicate
  One where clause.

Constants

• FORMAT_VERSION
  The version of JSON output that this crate represents.