Package convex.core.lang.ops

Class Let<T extends ACell>

java.lang.Object

convex.core.data.AObject

convex.core.data.ACell

convex.core.lang.AOp<T>

convex.core.lang.ops.AMultiOp<T>

convex.core.lang.ops.Let<T>

Type Parameters:

T - Result type of Op

All Implemented Interfaces:

IValidated, IWriteable

public class Let<T extends ACell>
extends AMultiOp<T>

Op for executing a body after lexically binding one or more symbols. Can represent (let [..] ..) and (loop [..] ..). Loop version can act as a target for (recur ...) expressions.

Field Summary

Fields

Modifier and Type	Field	Description
protected final int	bindingCount
protected final boolean	isLoop
protected final AVector<ACell>	symbols	Vector of binding forms.

Fields inherited from class convex.core.lang.ops.AMultiOp

ops

Fields inherited from class convex.core.data.ACell

cachedRef, memorySize

Fields inherited from class convex.core.data.AObject

encoding

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Let(AVector<ACell> syms, AVector<AOp<ACell>> ops, boolean isLoop)

Method Summary

Modifier and Type	Method	Description
static <T extends ACell> Let<T>	create(AVector<ACell> syms, AVector<AOp<ACell>> ops, boolean isLoop)
int	encodeRaw(byte[] bs, int pos)	Writes the raw data for this Op to the specified bytebuffer.
int	estimatedEncodingSize()	Estimate the encoded data size for this Cell.
Context	execute(Context context)	Executes this op with the given context.
Context	executeBody(Context ctx)
final <R extends ACell> Ref<R>	getRef(int i)	Gets a numbered child Ref from within this Cell.
int	getRefCount()	Gets the number of Refs contained within this Cell.
byte	opCode()	Returns the opcode for this op
boolean	print(BlobBuilder bb, long limit)	Prints this Object to a readable String Representation.
static <T extends ACell> Let<T>	read(Blob b, int pos, boolean isLoop)	Read a Let Op from a Blob encoding
protected Let<T>	recreate(ASequence<AOp<ACell>> newOps)	Recreates this object with an updated list of child Ops.
protected Let<T>	recreate(ASequence<AOp<ACell>> newOps, AVector<ACell> newSymbols)
Let<T>	updateRefs(IRefFunction func)	Updates all Refs in this object using the given function.

Methods inherited from class convex.core.lang.ops.AMultiOp

validateCell

Methods inherited from class convex.core.lang.AOp

encode, equals, getTag, getType, isCanonical, isCVMValue, isDataValue, toCanonical

Methods inherited from class convex.core.data.ACell

attachMemorySize, attachRef, cachedEncoding, cachedHash, calcMemorySize, createEncoding, createRef, equals, genericEquals, getCanonical, getChildRefs, getEncoding, getEncodingLength, getHash, getMemorySize, getMemorySize, getRef, hashCode, isEmbedded, toCVMString, toString, validate

Methods inherited from class convex.core.data.AObject

attachEncoding, print, print

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

symbols

protected final AVector<ACell> symbols

Vector of binding forms. Can be destructuring forms

bindingCount

protected final int bindingCount

isLoop

protected final boolean isLoop

Constructor Details

Let

protected Let(AVector<ACell> syms,
 AVector<AOp<ACell>> ops,
 boolean isLoop)

Method Details

create

public static <T extends ACell> Let<T> create(AVector<ACell> syms,
 AVector<AOp<ACell>> ops,
 boolean isLoop)

updateRefs

public Let<T> updateRefs(IRefFunction func)

Description copied from class: ACell

Updates all Refs in this object using the given function. The function *must not* change the hash value of Refs, in order to ensure structural integrity of modified data structures. The implementation *should* re-attach any original encoding in order to prevent re-encoding or surplus hashing This is a building block for a very sneaky trick that enables use to do a lot of efficient operations on large trees of smart references. Must return the same object if no Refs are altered.

Overrides:

updateRefs in class AMultiOp<T extends ACell>

Parameters:

func - Ref update function

Returns:

Cell with updated Refs

getRefCount

public int getRefCount()

Description copied from class: ACell

Gets the number of Refs contained within this Cell. This number is final / immutable for any given instance and is defined by the Cell encoding rules. Contained Refs may be either external or embedded.

Overrides:

getRefCount in class AMultiOp<T extends ACell>

Returns:

The number of Refs in this Cell

getRef

public final <R extends ACell> Ref<R> getRef(int i)

Description copied from class: ACell

Gets a numbered child Ref from within this Cell. WARNING: May need to convert to a canonical instance

Overrides:

getRef in class AMultiOp<T extends ACell>

Type Parameters:

R - Type of referenced Cell

Parameters:

i - Index of ref to get

Returns:

The Ref at the specified index

recreate

protected Let<T> recreate(ASequence<AOp<ACell>> newOps)

Description copied from class: AMultiOp

Recreates this object with an updated list of child Ops.

Specified by:

recreate in class AMultiOp<T extends ACell>

Parameters:

newOps -

Returns:

recreate

protected Let<T> recreate(ASequence<AOp<ACell>> newOps,
 AVector<ACell> newSymbols)

execute

public Context execute(Context context)

Description copied from class: AOp

Executes this op with the given context. Must preserve depth unless an exceptional is returned.

Specified by:

execute in class AOp<T extends ACell>

Parameters:

context - Initial Context

Returns:

The updated Context after executing this operation

executeBody

public Context executeBody(Context ctx)

print

public boolean print(BlobBuilder bb,
 long limit)

Description copied from class: AObject

Prints this Object to a readable String Representation. SECURITY: Must halt and return false in O(1) time when limit of printing is exceeded otherwise DoS attacks may be possible.

Specified by:

print in class AObject

Parameters:

bb - BlobBuilder to append to. May be partially written if print limit exceeded

limit - Limit of printing in string bytes

Returns:

True if fully printed within limit, false otherwise

opCode

public byte opCode()

Description copied from class: AOp

Returns the opcode for this op

Specified by:

opCode in class AOp<T extends ACell>

Returns:

Opcode as a byte

encodeRaw

public int encodeRaw(byte[] bs,
 int pos)

Description copied from class: AOp

Writes the raw data for this Op to the specified bytebuffer. Assumes Op tag and opcode already written.

Overrides:

encodeRaw in class AMultiOp<T extends ACell>

Parameters:

bs - Byte array to write to

pos - Position to write in byte array

Returns:

The updated position

estimatedEncodingSize

public int estimatedEncodingSize()

Description copied from interface: IWriteable

Estimate the encoded data size for this Cell. Used for quickly sizing buffers. Implementations should try to return a size that is highly likely to contain the entire object when encoded, including the tag byte. Should not traverse soft Refs, i.e. must be usable on arbitrary partial data structures

Specified by:

estimatedEncodingSize in interface IWriteable

Overrides:

estimatedEncodingSize in class AMultiOp<T extends ACell>

Returns:

The estimated size for the binary representation of this object.

read

public static <T extends ACell> Let<T> read(Blob b,
 int pos,
 boolean isLoop)
                                     throws BadFormatException

Read a Let Op from a Blob encoding

Parameters:

b - Blob to read from

pos - Start position in Blob (location of tag byte)

isLoop - Indicates if the Op should be considered a loop target

Returns:

New decoded instance

Throws:

BadFormatException - In the event of any encoding error