Copyright	(c) Christian Gram Kalhauge 2017
License	MIT
Maintainer	kalhuage@cs.ucla.edu
Safe Haskell	Safe
Language	Haskell2010

Language.JVM.Constant

Contents

Constant
Constant Pool

Description

This module contains the Constant type and the ConstantPool. These are essential for accessing data in the class-file.

Synopsis

Constant

data Constant Source #

A constant is a multi word item in the ConstantPool. Each of the constructors are pretty much self expiatory from the types.

Instances

Eq Constant Source #
Methods (==) :: Constant -> Constant -> Bool # (/=) :: Constant -> Constant -> Bool #
Show Constant Source #
Methods showsPrec :: Int -> Constant -> ShowS # show :: Constant -> String # showList :: [Constant] -> ShowS #
Binary Constant Source #
Methods put :: Constant -> Put # get :: Get Constant # putList :: [Constant] -> Put #

constantSize :: Constant -> Int Source #

Some of the Constants take up more space in the constant pool than other. Notice that String and MethodType is not of size 32, but is still awarded value 1. This is due to an inconsistency in JVM.

newtype ConstantRef Source #

A constant is referenced by the ConstantRef data type. It is just a 16 bit word, but wrapped for type safety.

Constructors

ConstantRef Word16

Instances

Eq ConstantRef Source #
Methods (==) :: ConstantRef -> ConstantRef -> Bool # (/=) :: ConstantRef -> ConstantRef -> Bool #
Show ConstantRef Source #
Methods showsPrec :: Int -> ConstantRef -> ShowS # show :: ConstantRef -> String # showList :: [ConstantRef] -> ShowS #
Generic ConstantRef Source #
Associated Types type Rep ConstantRef :: * -> * # Methods from :: ConstantRef -> Rep ConstantRef x # to :: Rep ConstantRef x -> ConstantRef #
Binary ConstantRef Source #
Methods put :: ConstantRef -> Put # get :: Get ConstantRef # putList :: [ConstantRef] -> Put #
type Rep ConstantRef Source #
type Rep ConstantRef = D1 (MetaData "ConstantRef" "Language.JVM.Constant" "jvm-binary-0.0.1-INqRQWrwNVD23mePMfBHSA" True) (C1 (MetaCons "ConstantRef" PrefixI False) (S1 (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word16)))

Constant Pool

The ConstantPool contains all the constants, and is accessible using the Lookup methods.

newtype ConstantPool Source #

A ConstantPool is just an IntMap. A IntMap is used, because constants are accessed after their byte-offset. constantSize

Constructors

ConstantPool
Fields unConstantPool :: IntMap Constant

Instances

Eq ConstantPool Source #
Methods (==) :: ConstantPool -> ConstantPool -> Bool # (/=) :: ConstantPool -> ConstantPool -> Bool #
Show ConstantPool Source #
Methods showsPrec :: Int -> ConstantPool -> ShowS # show :: ConstantPool -> String # showList :: [ConstantPool] -> ShowS #
Binary ConstantPool Source #
Methods put :: ConstantPool -> Put # get :: Get ConstantPool # putList :: [ConstantPool] -> Put #

lookupConstant :: ConstantRef -> ConstantPool -> Maybe Constant Source #

Lookup a Constant in the ConstantPool.

lookupText :: ConstantRef -> ConstantPool -> Maybe Text Source #

Lookup a Text in the ConstantPool, returns Nothing if the reference does not point to something in the ConstantPool, if it points to something not a String Constant, or if it is impossible to decode the ByteString as Utf8.

lookupClassName :: ConstantRef -> ConstantPool -> Maybe Text Source #

Lookup a class name in the ConstantPool, returns Nothing otherwise.

toListOfConstants :: ConstantPool -> [(ConstantRef, Constant)] Source #

Return a list of reference-constant pairs.

String !SizedByteString16
Integer !Word32
Float !Word32
Long !Word64
Double !Word64
ClassRef !ConstantRef
StringRef !ConstantRef
FieldRef !ConstantRef !ConstantRef
MethodRef !ConstantRef !ConstantRef
InterfaceMethodRef !ConstantRef !ConstantRef
NameAndType !ConstantRef !ConstantRef
MethodHandle !Word8 !ConstantRef
MethodType !ConstantRef
InvokeDynamic !ConstantRef !ConstantRef