Package convex.core.lang.ops

Class Lookup<T extends ACell>

java.lang.Object

convex.core.data.AObject

convex.core.data.ACell

convex.core.lang.AOp<T>

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

Type Parameters:

T - Result type of Op

All Implemented Interfaces:

IValidated, IWriteable

public class Lookup<T extends ACell>
extends AOp<T>

Op to look up a Symbol in the current execution context. Holds an optional Address to specify lookup in another Account environment. If null, the Lookup will be performed in the current environment. Consumes juice for lookup when executed.

Field Summary

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> Lookup<T>	create(Address addr, Symbol sym)
static <T extends ACell> Lookup<T>	create(Symbol symbol)
static <T extends ACell> Lookup<T>	create(AOp<Address> address, Symbol form)
static <T extends ACell> Lookup<T>	create(AOp<Address> address, String name)
static <T extends ACell> Lookup<T>	create(String name)
int	encodeRaw(byte[] bs, int pos)	Writes the raw data for this Op to the specified bytebuffer.
Context	execute(Context context)	Executes this op with the given context.
AOp<Address>	getAddress()
<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> Lookup<T>	read(Blob b, int pos)	Reads a Lookup op from a Blob encoding
Lookup<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.

Methods inherited from class convex.core.lang.AOp

encode, equals, estimatedEncodingSize, 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

Method Details

create

public static <T extends ACell> Lookup<T> create(AOp<Address> address,
 Symbol form)

create

public static <T extends ACell> Lookup<T> create(AOp<Address> address,
 String name)

create

public static <T extends ACell> Lookup<T> create(Address addr,
 Symbol sym)

create

public static <T extends ACell> Lookup<T> create(Symbol symbol)

create

public static <T extends ACell> Lookup<T> create(String name)

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

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.

Specified by:

encodeRaw in class AOp<T extends ACell>

Parameters:

bs - Byte array to write to

pos - Position to write in byte array

Returns:

The updated position

read

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

Reads a Lookup op from a Blob encoding

Type Parameters:

T - Type of Lookup value

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

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 Lookup<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 AOp<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

getAddress

public AOp<Address> getAddress()