avail/avail.interpreter.levelTwoSimple/L2Simple_AbstractReifiableInstruction

L2Simple_AbstractReifiableInstruction

abstract class L2Simple_AbstractReifiableInstruction(val stackp: Int, val pc: Int, val nextOffset: Int, val liveIndices: IntArray) : L2SimpleInstruction

An abstraction for instructions that can trigger reification during their execution. This includes instructions that invoke functions, create a label, or read/write a variable (which may fail and invoke handler code that may reify).

Inheritors

L2Simple_GetVariable

L2Simple_GetVariableClearing

L2Simple_GetOuter

L2Simple_GetOuterClearing

L2Simple_AbstractInvokerInstruction

L2Simple_CheckForInterrupt

Constructors

L2Simple_AbstractReifiableInstruction

constructor(stackp: Int, pc: Int, nextOffset: Int, liveIndices: IntArray)

Properties

liveIndices

val liveIndices: IntArray

nextOffset

val nextOffset: Int

val pc: Int

stackp

val stackp: Int

Functions

fieldValueToString

fun fieldValueToString(value: Any?): String

Generate a suitable print representation of the value.

handleVariableGetException

fun handleVariableGetException(e: VariableGetException, interpreter: Interpreter, registers: Array<AvailObject>): StackReifier

A VariableGetException has occurred. Invoke the READ_UNASSIGNED_VARIABLE hook function, which, because it is ⊥-valued, can only reify. Eventually answer that StackReifier.

handleVariableSetException

fun handleVariableSetException(e: VariableSetException, variable: A_Variable, value: AvailObject, interpreter: Interpreter, registers: Array<AvailObject>): StackReifier?

A VariableSetException has occurred. Run the implicit-observe handler, and answer null if it completes, or a suitable StackReifier if it eventually reifies.

reenter

open override fun reenter(registers: Array<AvailObject>, interpreter: Interpreter): StackReifier?

A previously constructed continuation is being resumed in some way, and the instruction just before the continuation's L2 offset has been asked to do anything specific to reentering the continuation. For example, a method call might be forced to reify the stack, but at resumption time (i.e., when "returning" into it), it will still need to check the type of the "returned" value against the expected type.

step

abstract fun step(registers: Array<AvailObject>, interpreter: Interpreter): StackReifier?

Perform this instruction, a single step of an L2SimpleChunk. The mutable Array of AvailObjects acts as a simple set of registers. Element 0 is the current function, and the remaining elements correspond with the continuation slots, should one need to be constructed.

toString

open override fun toString(): String