Documentation
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Index ¶
Constants ¶
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const ( // ErrBadInstruction is raised when a call to isa.New can't succeed due to // either missing or excessive operands ErrBadInstruction = "instruction operand mismatch: %s" // ErrExpectedOperand is raised when an Operand isn't represented by an // unsigned Word that will fit within the number of Operand bits ErrExpectedOperand = "expected unsigned operand: %d" )
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const ( // OpcodeSize are the number of bits required for an Opcode value OpcodeSize = 6 // OpcodeMask masks the bits for encoding an Opcode into an Instruction OpcodeMask = Opcode(1<<OpcodeSize - 1) // OperandMask masks the bits for encoding an Operand into an Instruction OperandMask = ^Operand(OpcodeMask) >> OpcodeSize // Label is an internal Opcode Label = OpcodeMask )
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const ErrEffectNotDeclared = "effect not declared for opcode: %s"
ErrEffectNotDeclared is raised when an attempt to forcefully retrieve an Effect fails
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const ErrLabelAlreadyAnchored = "label has already been anchored"
ErrLabelAlreadyAnchored is raised when the flattener identifies that a label has been anchored more than once in the Instructions stream
Variables ¶
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var Effects = map[Opcode]*Effect{ Add: {Pop: 2, Push: 1}, Arg: {Push: 1, Operand: Arguments}, ArgLen: {Push: 1}, Bind: {Pop: 2}, BindRef: {Pop: 2}, Call: {Pop: 1, Push: 1, DPop: true, Operand: Stack}, Call0: {Pop: 1, Push: 1}, Call1: {Pop: 2, Push: 1}, CallWith: {Pop: 2, Push: 1}, Car: {Pop: 1, Push: 1}, Cdr: {Pop: 1, Push: 1}, Closure: {Push: 1, Operand: Values}, CondJump: {Pop: 1, Operand: Labels}, Cons: {Pop: 2, Push: 1}, Const: {Push: 1, Operand: Constants}, Declare: {Pop: 1}, Deref: {Pop: 1, Push: 1}, Div: {Pop: 2, Push: 1}, Dup: {Pop: 1, Push: 2}, Empty: {Pop: 1, Push: 1}, Eq: {Pop: 2, Push: 1}, False: {Push: 1}, Jump: {Operand: Labels}, Label: {Ignore: true, Operand: Labels}, Load: {Push: 1, Operand: Locals}, Mod: {Pop: 2, Push: 1}, Mul: {Pop: 2, Push: 1}, Neg: {Pop: 1, Push: 1}, NegInt: {Push: 1, Operand: Integer}, NewRef: {Push: 1}, Null: {Push: 1}, NoOp: {Ignore: true}, Not: {Pop: 1, Push: 1}, NumEq: {Pop: 2, Push: 1}, NumGt: {Pop: 2, Push: 1}, NumGte: {Pop: 2, Push: 1}, NumLt: {Pop: 2, Push: 1}, NumLte: {Pop: 2, Push: 1}, Panic: {Pop: 1, Exit: true}, Pop: {Pop: 1}, PosInt: {Push: 1, Operand: Integer}, Private: {Pop: 1}, Resolve: {Pop: 1, Push: 1}, RestArg: {Push: 1, Operand: Arguments}, RetFalse: {Exit: true}, RetNull: {Exit: true}, RetTrue: {Exit: true}, Return: {Pop: 1, Exit: true}, Store: {Pop: 1, Operand: Locals}, Sub: {Pop: 2, Push: 1}, TailCall: {Pop: 1, DPop: true, Operand: Stack}, True: {Push: 1}, Zero: {Push: 1}, }
Effects is a lookup table of instruction effects
Functions ¶
func IsValidOperand ¶
IsValidOperand returns true if the int falls within the operand range
Types ¶
type Effect ¶
type Effect struct {
Operand ActOn // Describe elements the operands act on
Pop int // A fixed number of items to be popped from the stack
Push int // A fixed number of items to be pushed onto the stack
DPop bool // Dynamic number of items to be popped (in operand)
Ignore bool // Skip this instruction (ex: Labels and NoOps)
Exit bool // Results in a termination of the abstract machine
}
Effect captures how an Instruction impacts the state of the machine
func MustGetEffect ¶
MustGetEffect gives you effect information or explodes violently
type Instruction ¶
type Instruction Word
Instruction represents a single instruction and its operand
func (Instruction) Equal ¶
func (i Instruction) Equal(v data.Value) bool
Equal compares this Instruction to another for equality
func (Instruction) Opcode ¶
func (i Instruction) Opcode() Opcode
func (Instruction) Operand ¶
func (i Instruction) Operand() Operand
func (Instruction) Split ¶
func (i Instruction) Split() (Opcode, Operand)
func (Instruction) String ¶
func (i Instruction) String() string
type Instructions ¶
type Instructions []Instruction
Instructions represent a set of Instructions
func Flatten ¶
func Flatten(code Instructions) Instructions
Flatten takes a set of Instructions and flattens them into something that the abstract machine can execute
func (Instructions) String ¶
func (i Instructions) String() string
type Opcode ¶
type Opcode Word
Opcode represents an Instruction's operation
const ( Add Opcode = iota // Addition Arg // Retrieve Argument Value ArgLen // Retrieve Argument Count Bind // Bind Global BindRef // Bind Reference Call // Call Procedure Call0 // Zero-Arg Call Call1 // One-Arg Call CallWith // Call with the provided Sequence as Arguments Car // Contents of the Address part of the Register Cdr // Contents of the Decrement part of the Register Closure // Retrieve Closure Value CondJump // Conditional Jump Cons // Form a new Cons Cell (or Prepend) Const // Retrieve Constant Declare // Declare a public Namespace entry Deref // Pointer Dereference Div // Division Dup // Duplicate Value Empty // Tests Empty Sequence Eq // Value Equality False // Push False Jump // Absolute Jump Load // Retrieve Local Value Mod // Remainder Mul // Multiplication Neg // Negation NegInt // Push Negative Integer (in Operand) NewRef // New Reference NoOp // Error-Operator Not // Boolean Negation Null // Push Null NumEq // Numeric Equality NumGt // Greater Than NumGte // Greater or Equal To NumLt // Less Than Comparison NumLte // Less or Equal To Panic // Abnormally Halt Pop // Discard Value PosInt // Push Positive Integer (in Operand) Private // Declare a private Namespace entry Resolve // Resolve Global Symbol RestArg // Retrieve Arguments Tail RetFalse // Return False RetNull // Return Null (Empty List) RetTrue // Return True Return // Return Value Store // Store Local Sub // Subtraction TailCall // Tail Call True // Push True Zero // Push Zero )
func (Opcode) New ¶
func (o Opcode) New(ops ...Operand) Instruction
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