clojure.reflect

by Stuart Halloway

Full namespace name: clojure.reflect

Overview

Reflection on Host Types
Alpha - subject to change.

Two main entry points: 

* type-reflect reflects on something that implements TypeReference.
* reflect (for REPL use) reflects on the class of an instance, or
  on a class if passed a class

Key features:

* Exposes the read side of reflection as pure data. Reflecting
  on a type returns a map with keys :bases, :flags, and :members.

* Canonicalizes class names as Clojure symbols. Types can extend
  to the TypeReference protocol to indicate that they can be
  unambiguously resolved as a type name. The canonical format
  requires one non-Java-ish convention: array brackets are <>
  instead of [] so they can be part of a Clojure symbol.

* Pluggable Reflectors for different implementations. The default
  JavaReflector is good when you have a class in hand, or use
  the AsmReflector for "hands off" reflection without forcing
  classes to load.

Platform implementers must:

* Create an implementation of Reflector.
* Create one or more implementations of TypeReference.
* def default-reflector to be an instance that satisfies Reflector.

Added in Clojure version 1.3

Protocols

ClassResolverProtocol

Known implementations: clojure.lang.Fn, java.lang.ClassLoader

resolve-classfunction

Usage: (resolve-class this name)

Given a class name, return that typeref's class bytes as an InputStream.

Source

ReflectorProtocol

Protocol for reflection implementers.

Known implementations: AsmReflector, JavaReflector

do-reflectfunction

Usage: (do-reflect reflector typeref)

Source

TypeReferenceProtocol

A TypeReference can be unambiguously converted to a type name on
the host platform.

All typerefs are normalized into symbols. If you need to
normalize a typeref yourself, call typesym.

Known implementations: clojure.asm.Type, clojure.lang.Symbol, java.lang.Class

typenamefunction

Usage: (typename o)

Returns Java name as returned by ASM getClassName, e.g. byte[], java.lang.String[]

Source

Types

AsmReflectortype

Fields: [class-resolver]
Protocols: Reflector
Interfaces:

Constructorrecord

Fields: [name declaring-class parameter-types exception-types flags]
Protocols:
Interfaces: clojure.lang.IHashEq, clojure.lang.IKeywordLookup, clojure.lang.ILookup, clojure.lang.IObj, clojure.lang.IPersistentMap, java.io.Serializable, java.util.Map

Fieldrecord

Fields: [name type declaring-class flags]
Protocols:
Interfaces: clojure.lang.IHashEq, clojure.lang.IKeywordLookup, clojure.lang.ILookup, clojure.lang.IObj, clojure.lang.IPersistentMap, java.io.Serializable, java.util.Map

JavaReflectortype

Fields: [classloader]
Protocols: Reflector
Interfaces:

Methodrecord

Fields: [name return-type declaring-class parameter-types exception-types flags]
Protocols:
Interfaces: clojure.lang.IHashEq, clojure.lang.IKeywordLookup, clojure.lang.ILookup, clojure.lang.IObj, clojure.lang.IPersistentMap, java.io.Serializable, java.util.Map

Public Variables and Functions

->AsmReflectorfunction

Usage: (->AsmReflector class-resolver)

Positional factory function for class clojure.reflect.AsmReflector.

Source

->Constructorfunction

Usage: (->Constructor name declaring-class parameter-types exception-types flags)

Positional factory function for class clojure.reflect.Constructor.

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->Fieldfunction

Usage: (->Field name type declaring-class flags)

Positional factory function for class clojure.reflect.Field.

Source

->JavaReflectorfunction

Usage: (->JavaReflector classloader)

Positional factory function for class clojure.reflect.JavaReflector.

Source

->Methodfunction

Usage: (->Method name return-type declaring-class parameter-types exception-types flags)

Positional factory function for class clojure.reflect.Method.

Source

flag-descriptorsvar

The Java access bitflags, along with their friendly names and
the kinds of objects to which they can apply.

Source

map->Constructorfunction

Usage: (map->Constructor m#)

Factory function for class clojure.reflect.Constructor, taking a map of keywords to field values.

Source

map->Fieldfunction

Usage: (map->Field m#)

Factory function for class clojure.reflect.Field, taking a map of keywords to field values.

Source

map->Methodfunction

Usage: (map->Method m#)

Factory function for class clojure.reflect.Method, taking a map of keywords to field values.

Source

reflectfunction

Usage: (reflect obj & options)

Alpha - subject to change.
Reflect on the type of obj (or obj itself if obj is a class).
Return value and options are the same as for type-reflect. 

Added in Clojure version 1.3

Source

type-reflectfunction

Usage: (type-reflect typeref & options)

Alpha - subject to change.
 Reflect on a typeref, returning a map with :bases, :flags, and
:members. In the discussion below, names are always Clojure symbols.

 :bases            a set of names of the type's bases
 :flags            a set of keywords naming the boolean attributes
                   of the type.
 :members          a set of the type's members. Each member is a map
                   and can be a constructor, method, or field.

 Keys common to all members:
 :name             name of the type 
 :declaring-class  name of the declarer
 :flags            keyword naming boolean attributes of the member

 Keys specific to constructors:
 :parameter-types  vector of parameter type names
 :exception-types  vector of exception type names

 Key specific to methods:
 :parameter-types  vector of parameter type names
 :exception-types  vector of exception type names
 :return-type      return type name

 Keys specific to fields:
 :type             type name

 Options:

   :ancestors     in addition to the keys described above, also
                  include an :ancestors key with the entire set of
                  ancestors, and add all ancestor members to
                  :members.
   :reflector     implementation to use. Defaults to JavaReflector,
                  AsmReflector is also an option.

Added in Clojure version 1.3

Source