Package convex.core.lang.impl

Class Fn<T extends ACell>

java.lang.Object

convex.core.data.AObject

convex.core.data.ACell

convex.core.lang.AFn<T>

convex.core.lang.impl.AClosure<T>

convex.core.lang.impl.Fn<T>

Type Parameters:

T - Return type of function

All Implemented Interfaces:

IValidated, IWriteable, IFn<T>

public class Fn<T extends ACell>
extends AClosure<T>

Value class representing a instantiated closure / lambda function. Includes the following information:

1. Parameters of the function, as a vector of Syntax objects
2. Body of the function, as a compiled operation
3. captured lexical bindings at time of creation.

Field Summary

Fields inherited from class convex.core.lang.impl.AClosure

lexicalEnv

Fields inherited from class convex.core.data.ACell

cachedRef, memorySize

Fields inherited from class convex.core.data.AObject

encoding

Method Summary

Modifier and Type	Method	Description
static <T extends ACell, I> Fn<T>	create(AVector<ACell> params, AOp<T> body)
int	encode(byte[] bs, int pos)	Writes this Cell's encoding to a byte array, including a tag byte which will be written first.
int	encodeRaw(byte[] bs, int pos)	Writes this Cell's encoding to a byte array, excluding the tag byte.
int	estimatedEncodingSize()	Estimate the encoded data size for this Cell.
AOp<T>	getBody()
AVector<ACell>	getParams()	Returns the declared param names for a function.
<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.
boolean	hasArity(int n)	Tests if this function supports the given arity.
Context	invoke(Context context, ACell[] args)	Invoke this function in the given context.
boolean	isCanonical()	Returns true if this Cell is in a canonical representation.
boolean	print(BlobBuilder sb, long limit)	Prints this Object to a readable String Representation.
boolean	printInternal(BlobBuilder sb, long limit)	Print the "internal" representation of a closure e.g.
static <T extends ACell> Fn<T>	read(Blob b, int pos)	Decodes a function instance from a Blob encoding.
ACell	toCanonical()	Converts this Cell to a canonical version.
Fn<T>	updateRefs(IRefFunction func)	Updates all Refs in this object using the given function.
void	validateCell()	Validates the local structure and invariants of this cell.
<F extends AClosure<T>> F	withEnvironment(AVector<ACell> env)	Produces an copy of this closure with the specified environment

Methods inherited from class convex.core.lang.AFn

equals, getTag, getType, isCVMValue, isDataValue, supportsArgs

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

Method Details

create

public static <T extends ACell,
I> Fn<T> create(AVector<ACell> params,
 AOp<T> body)

withEnvironment

public <F extends AClosure<T>> F withEnvironment(AVector<ACell> env)

Description copied from class: AClosure

Produces an copy of this closure with the specified environment

Specified by:

withEnvironment in class AClosure<T extends ACell>

Parameters:

env - New lexical environment to use for this closure

Returns:

Closure updated with new lexical environment

hasArity

public boolean hasArity(int n)

Description copied from class: AFn

Tests if this function supports the given arity.

Specified by:

hasArity in class AFn<T extends ACell>

Parameters:

n - Arity to check

Returns:

true if function supports the given arity, false otherwise

invoke

public Context invoke(Context context,
 ACell[] args)

Description copied from interface: IFn

Invoke this function in the given context.

Specified by:

invoke in interface IFn<T extends ACell>

Specified by:

invoke in class AFn<T extends ACell>

Parameters:

context - Context in which the function is to be executed

args - Arguments to the function

Returns:

Context containing result of function invocation, or an exceptional value

isCanonical

public boolean isCanonical()

Description copied from class: ACell

Returns true if this Cell is in a canonical representation. Non-canonical objects may be used on a temporary internal basis, they should be converted to canonical representations for general purpose use.

Specified by:

isCanonical in class ACell

Returns:

true if the object is in canonical format, false otherwise

encode

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

Description copied from class: ACell

Writes this Cell's encoding to a byte array, including a tag byte which will be written first. Cell must be canonical, or else an error may occur.

Specified by:

encode in interface IWriteable

Specified by:

encode in class ACell

Parameters:

bs - A byte array to which to write the encoding

pos - The offset into the byte array

Returns:

New position after writing

encodeRaw

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

Description copied from class: ACell

Writes this Cell's encoding to a byte array, excluding the tag byte.

Specified by:

encodeRaw in class ACell

Parameters:

bs - A byte array to which to write the encoding

pos - The offset into the byte array

Returns:

New position after writing

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

Returns:

The estimated size for the binary representation of this object.

read

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

Decodes a function instance from a Blob encoding.

Parameters:

b - Blob to read from

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

Returns:

New decoded instance

Throws:

BadFormatException - In the event of any encoding error

print

public boolean print(BlobBuilder sb,
 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:

sb - 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

printInternal

public boolean printInternal(BlobBuilder sb,
 long limit)

Description copied from class: AClosure

Print the "internal" representation of a closure e.g. "[x] 1", excluding the 'fn' symbol.

Specified by:

printInternal in class AClosure<T extends ACell>

Parameters:

sb - StringBuilder to print to

limit - Limit of BlobBuilder size

Returns:

True if printed successfully within limit, false otherwise

getParams

public AVector<ACell> getParams()

Returns the declared param names for a function.

Returns:

A binding vector describing the parameters for this function

getBody

public AOp<T> getBody()

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 ACell

Returns:

The number of Refs in this Cell

getRef

public <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 ACell

Type Parameters:

R - Type of referenced Cell

Parameters:

i - Index of ref to get

Returns:

The Ref at the specified index

updateRefs

public Fn<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.

Specified by:

updateRefs in class AFn<T extends ACell>

Parameters:

func - Ref update function

Returns:

Cell with updated Refs

validateCell

public void validateCell()
                  throws InvalidDataException

Description copied from class: ACell

Validates the local structure and invariants of this cell. Called by validate() super implementation. Should validate directly contained data, but should not validate all other structure of this cell. In particular, should not traverse potentially missing child Refs.

Specified by:

validateCell in class ACell

Throws:

InvalidDataException - If the Cell is invalid

toCanonical

public ACell toCanonical()

Description copied from class: ACell

Converts this Cell to a canonical version. Must return this Cell if already canonical, may be O(n) in size of value otherwise. Callers should usually use getCanonical(), which caches canonical instances once created

Specified by:

toCanonical in class ACell

Returns:

Canonical version of Cell