vvm

package
v0.4.0 Latest Latest
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This package is not in the latest version of its module.

 Go to latest Published: Aug 3, 2025 License: MIT, MIT Imports: 19 Imported by: 0

Documentation

Index

Constants

View Source 
const (
	// GlobalsSize is the maximum number of global variables for a VM.
	GlobalsSize = 1024

	// StackSize is the maximum stack size for a VM.
	StackSize = 2048

	// MaxFrames is the maximum number of function frames for a VM.
	MaxFrames = 1024
)

Variables

View Source 
var (
	// ErrStackOverflow is a stack overflow error.
	ErrStackOverflow = errors.New("stack overflow")

	// ErrObjectAllocLimit is an objects allocation limit error.
	ErrObjectAllocLimit = errors.New("object allocation limit exceeded")

	// ErrIndexOutOfBounds is an error where a given index is out of the
	// bounds.
	ErrIndexOutOfBounds = errors.New("index out of bounds")

	// ErrInvalidIndexType represents an invalid index type.
	ErrInvalidIndexType = errors.New("invalid index type")

	// ErrInvalidIndexValueType represents an invalid index value type.
	ErrInvalidIndexValueType = errors.New("invalid index value type")

	// ErrInvalidIndexOnError represents an invalid index on error.
	ErrInvalidIndexOnError = errors.New("invalid index on error")

	// ErrInvalidOperator represents an error for invalid operator usage.
	ErrInvalidOperator = errors.New("invalid operator")

	// ErrWrongNumArguments represents a wrong number of arguments error.
	ErrWrongNumArguments = errors.New("wrong number of arguments")

	// ErrBytesLimit represents an error where the size of bytes value exceeds
	// the limit.
	ErrBytesLimit = errors.New("exceeding bytes size limit")

	// ErrStringLimit represents an error where the size of string value
	// exceeds the limit.
	ErrStringLimit = errors.New("exceeding string size limit")

	// ErrNotIndexable is an error where an Object is not indexable.
	ErrNotIndexable = errors.New("not indexable")

	// ErrNotIndexAssignable is an error where an Object is not index
	// assignable.
	ErrNotIndexAssignable = errors.New("not index-assignable")

	// ErrNotImplemented is an error where an Object has not implemented a
	// required method.
	ErrNotImplemented = errors.New("not implemented")

	// ErrInvalidRangeStep is an error where the step parameter is less than or equal to 0 when using builtin range function.
	ErrInvalidRangeStep = errors.New("range step must be greater than 0")

	// ErrVMAborted is an error to denote the VM was forcibly terminated without proper exit.
	ErrVMAborted = errors.New("virtual machine aborted")
)
View Source 
var (
	// MaxStringLen is the maximum byte-length for string value. Note this
	// limit applies to all compiler/VM instances in the process.
	MaxStringLen = 2147483647

	// MaxBytesLen is the maximum length for bytes value. Note this limit
	// applies to all compiler/VM instances in the process.
	MaxBytesLen = 2147483647
)

Functions

func CountObjects 

func CountObjects(o Object) (c int)

CountObjects returns the number of objects that a given object o contains. For scalar value types, it will always be 1. For compound value types, this will include its elements and all of their elements recursively.

func Format 

func Format(format string, a ...Object) (string, error)

Format is like fmt.Sprintf but using Objects.

func FormatInstructions 

func FormatInstructions(b []byte, posOffset int) []string

FormatInstructions returns string representation of bytecode instructions.

func MakeInstruction 

func MakeInstruction(opcode parser.Opcode, operands ...int) []byte

MakeInstruction returns a bytecode for an opcode and the operands.

func MarshalObject added in v0.4.0 

func MarshalObject(n int, b []byte, o Object) int

MarshalObject marshals the given object into a byte slice.

func SizeOfObject added in v0.4.0 

func SizeOfObject(o Object) int

SizeOfObject returns the size of the given object.

func SizeOfObjectPtr added in v0.4.0 

func SizeOfObjectPtr(op *ObjectPtr) int

SizeOfObjectPtr returns the size of the given object pointer.

func ToBool 

func ToBool(o Object) (v bool, ok bool)

ToBool will try to convert object o to bool value.

func ToByteSlice 

func ToByteSlice(o Object) (v []byte, ok bool)

ToByteSlice will try to convert object o to []byte value.

func ToFloat64 

func ToFloat64(o Object) (v float64, ok bool)

ToFloat64 will try to convert object o to float64 value.

func ToInt 

func ToInt(o Object) (v int, ok bool)

ToInt will try to convert object o to int value.

func ToInt64 

func ToInt64(o Object) (v int64, ok bool)

ToInt64 will try to convert object o to int64 value.

func ToInterface 

func ToInterface(o Object) (res interface{})

ToInterface attempts to convert an object o to an interface{} value

func ToRune 

func ToRune(o Object) (v rune, ok bool)

ToRune will try to convert object o to rune value.

func ToString 

func ToString(o Object) (v string, ok bool)

ToString will try to convert object o to string value.

func ToTime 

func ToTime(o Object) (v time.Time, ok bool)

ToTime will try to convert object o to time.Time value.

func TypeOfObject added in v0.4.0 

func TypeOfObject(o Object) byte

TypeOfObject returns the type code of the given object.

Types

type Array 

type Array struct {
	ObjectImpl
	Value []Object
}

Array represents an array of objects.

func (*Array) BinaryOp 

func (o *Array) BinaryOp(op token.Token, rhs Object) (Object, error)

BinaryOp returns another object that is the result of a given binary operator and a right-hand side object.

func (*Array) CanIterate 

func (o *Array) CanIterate() bool

CanIterate returns whether the Object can be Iterated.

func (*Array) Copy 

func (o *Array) Copy() Object

Copy returns a copy of the type.

func (*Array) Equals 

func (o *Array) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Array) IndexGet 

func (o *Array) IndexGet(index Object) (res Object, err error)

IndexGet returns an element at a given index.

func (*Array) IndexSet 

func (o *Array) IndexSet(index, value Object) (err error)

IndexSet sets an element at a given index.

func (*Array) IsFalsy 

func (o *Array) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Array) Iterate 

func (o *Array) Iterate() Iterator

Iterate creates an array iterator.

func (*Array) String 

func (o *Array) String() string

func (*Array) TypeName 

func (o *Array) TypeName() string

TypeName returns the name of the type.

type ArrayIterator 

type ArrayIterator struct {
	ObjectImpl
	// contains filtered or unexported fields
}

ArrayIterator is an iterator for an array.

func (*ArrayIterator) Copy 

func (i *ArrayIterator) Copy() Object

Copy returns a copy of the type.

func (*ArrayIterator) Equals 

func (i *ArrayIterator) Equals(Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*ArrayIterator) IsFalsy 

func (i *ArrayIterator) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*ArrayIterator) Key 

func (i *ArrayIterator) Key() Object

Key returns the key or index value of the current element.

func (*ArrayIterator) Next 

func (i *ArrayIterator) Next() bool

Next returns true if there are more elements to iterate.

func (*ArrayIterator) String 

func (i *ArrayIterator) String() string

func (*ArrayIterator) TypeName 

func (i *ArrayIterator) TypeName() string

TypeName returns the name of the type.

func (*ArrayIterator) Value 

func (i *ArrayIterator) Value() Object

Value returns the value of the current element.

type Bool 

type Bool struct {
	ObjectImpl
	// contains filtered or unexported fields
}

Bool represents a boolean value.

func (*Bool) Copy 

func (o *Bool) Copy() Object

Copy returns a copy of the type.

func (*Bool) Equals 

func (o *Bool) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Bool) IsFalsy 

func (o *Bool) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Bool) String 

func (o *Bool) String() string

func (*Bool) TypeName 

func (o *Bool) TypeName() string

TypeName returns the name of the type.

type BuiltinFunction 

type BuiltinFunction struct {
	ObjectImpl
	Name  string
	Value CallableFunc
}

BuiltinFunction represents a builtin function.

func GetAllBuiltinFunctions 

func GetAllBuiltinFunctions() []*BuiltinFunction

GetAllBuiltinFunctions returns all builtin function objects.

func (*BuiltinFunction) Call 

func (o *BuiltinFunction) Call(ctx context.Context, args ...Object) (Object, error)

Call executes a builtin function.

func (*BuiltinFunction) CanCall 

func (o *BuiltinFunction) CanCall() bool

CanCall returns whether the Object can be Called.

func (*BuiltinFunction) Copy 

func (o *BuiltinFunction) Copy() Object

Copy returns a copy of the type.

func (*BuiltinFunction) Equals 

func (o *BuiltinFunction) Equals(_ Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*BuiltinFunction) String 

func (o *BuiltinFunction) String() string

func (*BuiltinFunction) TypeName 

func (o *BuiltinFunction) TypeName() string

TypeName returns the name of the type.

type BuiltinModule 

type BuiltinModule struct {
	Attrs map[string]Object
}

BuiltinModule is an importable module that's written in Go.

func (*BuiltinModule) AsImmutableMap 

func (m *BuiltinModule) AsImmutableMap(moduleName string) *ImmutableMap

AsImmutableMap converts builtin module into an immutable map.

func (*BuiltinModule) Import 

func (m *BuiltinModule) Import(moduleName string) (interface{}, error)

Import returns an immutable map for the module.

type Bytecode 

type Bytecode struct {
	FileSet      *parser.SourceFileSet
	MainFunction *CompiledFunction
	Constants    []Object
}

Bytecode is a compiled instructions and constants.

func (*Bytecode) CountObjects 

func (b *Bytecode) CountObjects() int

CountObjects returns the number of objects found in Constants.

func (*Bytecode) Equals 

func (b *Bytecode) Equals(other *Bytecode) bool

Equals compares two Bytecode instances for equality.

func (*Bytecode) FormatConstants 

func (b *Bytecode) FormatConstants() (output []string)

FormatConstants returns human readable string representations of compiled constants.

func (*Bytecode) FormatInstructions 

func (b *Bytecode) FormatInstructions() []string

FormatInstructions returns human readable string representations of compiled instructions.

func (*Bytecode) Marshal added in v0.4.0 

func (b *Bytecode) Marshal() ([]byte, error)

Marshal writes Bytecode data to the writer.

func (*Bytecode) RemoveDuplicates 

func (b *Bytecode) RemoveDuplicates()

RemoveDuplicates finds and remove the duplicate values in Constants. Note this function mutates Bytecode.

func (*Bytecode) Unmarshal added in v0.4.0 

func (b *Bytecode) Unmarshal(data []byte, modules *ModuleMap) (err error)

Unmarshal decodes Bytecode from the given data.

type Bytes 

type Bytes struct {
	ObjectImpl
	Value []byte
}

Bytes represents a byte array.

func (*Bytes) BinaryOp 

func (o *Bytes) BinaryOp(op token.Token, rhs Object) (Object, error)

BinaryOp returns another object that is the result of a given binary operator and a right-hand side object.

func (*Bytes) CanIterate 

func (o *Bytes) CanIterate() bool

CanIterate returns whether the Object can be Iterated.

func (*Bytes) Copy 

func (o *Bytes) Copy() Object

Copy returns a copy of the type.

func (*Bytes) Equals 

func (o *Bytes) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Bytes) IndexGet 

func (o *Bytes) IndexGet(index Object) (res Object, err error)

IndexGet returns an element (as Int) at a given index.

func (*Bytes) IsFalsy 

func (o *Bytes) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Bytes) Iterate 

func (o *Bytes) Iterate() Iterator

Iterate creates a bytes iterator.

func (*Bytes) String 

func (o *Bytes) String() string

func (*Bytes) TypeName 

func (o *Bytes) TypeName() string

TypeName returns the name of the type.

type BytesIterator 

type BytesIterator struct {
	ObjectImpl
	// contains filtered or unexported fields
}

BytesIterator represents an iterator for a string.

func (*BytesIterator) Copy 

func (i *BytesIterator) Copy() Object

Copy returns a copy of the type.

func (*BytesIterator) Equals 

func (i *BytesIterator) Equals(Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*BytesIterator) Key 

func (i *BytesIterator) Key() Object

Key returns the key or index value of the current element.

func (*BytesIterator) Next 

func (i *BytesIterator) Next() bool

Next returns true if there are more elements to iterate.

func (*BytesIterator) String 

func (i *BytesIterator) String() string

func (*BytesIterator) TypeName 

func (i *BytesIterator) TypeName() string

TypeName returns the name of the type.

func (*BytesIterator) Value 

func (i *BytesIterator) Value() Object

Value returns the value of the current element.

type CallableFunc 

type CallableFunc = func(ctx context.Context, args ...Object) (ret Object, err error)

CallableFunc is a function signature for the callable functions.

type Char 

type Char struct {
	ObjectImpl
	Value rune
}

Char represents a character value.

func (*Char) BinaryOp 

func (o *Char) BinaryOp(op token.Token, rhs Object) (Object, error)

BinaryOp returns another object that is the result of a given binary operator and a right-hand side object.

func (*Char) Copy 

func (o *Char) Copy() Object

Copy returns a copy of the type.

func (*Char) Equals 

func (o *Char) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Char) IsFalsy 

func (o *Char) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Char) String 

func (o *Char) String() string

func (*Char) TypeName 

func (o *Char) TypeName() string

TypeName returns the name of the type.

type CompiledFunction 

type CompiledFunction struct {
	ObjectImpl
	Instructions  []byte
	NumLocals     int // number of local variables (including function parameters)
	NumParameters int
	VarArgs       bool
	SourceMap     map[int]parser.Pos
	Free          []*ObjectPtr
}

CompiledFunction represents a compiled function.

func (*CompiledFunction) CanCall 

func (o *CompiledFunction) CanCall() bool

CanCall returns whether the Object can be Called.

func (*CompiledFunction) Copy 

func (o *CompiledFunction) Copy() Object

Copy returns a copy of the type.

func (*CompiledFunction) Equals 

func (o *CompiledFunction) Equals(_ Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*CompiledFunction) SourcePos 

func (o *CompiledFunction) SourcePos(ip int) parser.Pos

SourcePos returns the source position of the instruction at ip.

func (*CompiledFunction) String 

func (o *CompiledFunction) String() string

func (*CompiledFunction) TypeName 

func (o *CompiledFunction) TypeName() string

TypeName returns the name of the type.

type Compiler 

type Compiler struct {
	// contains filtered or unexported fields
}

Compiler compiles the AST into a bytecode.

func NewCompiler 

func NewCompiler(file *parser.SourceFile, symbolTable *SymbolTable, constants []Object, modules *ModuleMap, trace io.Writer) *Compiler

NewCompiler creates a Compiler.

func (*Compiler) Bytecode 

func (c *Compiler) Bytecode() *Bytecode

Bytecode returns a compiled bytecode.

func (*Compiler) Compile 

func (c *Compiler) Compile(node parser.Node) error

Compile compiles the AST node.

func (*Compiler) EnableFileImport 

func (c *Compiler) EnableFileImport(enable bool)

EnableFileImport enables or disables module loading from local files. Local file modules are disabled by default.

func (*Compiler) SetImportDir 

func (c *Compiler) SetImportDir(dir string)

SetImportDir sets the initial import directory path for file imports.

type CompilerError 

type CompilerError struct {
	FileSet *parser.SourceFileSet
	Node    parser.Node
	Err     error
}

CompilerError represents a compiler error.

func (*CompilerError) Error 

func (e *CompilerError) Error() string

type ContextKey 

type ContextKey string

ContextKey is a type for context keys used in the VM.

func (ContextKey) String 

func (c ContextKey) String() string

type ErrInvalidArgumentType 

type ErrInvalidArgumentType struct {
	Name     string
	Expected string
	Found    string
}

ErrInvalidArgumentType represents an invalid argument value type error.

func (ErrInvalidArgumentType) Error 

func (e ErrInvalidArgumentType) Error() string

type ErrPanic 

type ErrPanic struct {
	// contains filtered or unexported fields
}

ErrPanic is an error where panic happended in the VM.

func (ErrPanic) Error 

func (e ErrPanic) Error() string

type Error 

type Error struct {
	ObjectImpl
	Value Object
}

Error represents an error value.

func (*Error) Copy 

func (o *Error) Copy() Object

Copy returns a copy of the type.

func (*Error) Equals 

func (o *Error) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Error) IndexGet 

func (o *Error) IndexGet(index Object) (res Object, err error)

IndexGet returns an element at a given index.

func (*Error) IsFalsy 

func (o *Error) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Error) String 

func (o *Error) String() string

func (*Error) TypeName 

func (o *Error) TypeName() string

TypeName returns the name of the type.

type Float 

type Float struct {
	ObjectImpl
	Value float64
}

Float represents a floating point number value.

func (*Float) BinaryOp 

func (o *Float) BinaryOp(op token.Token, rhs Object) (Object, error)

BinaryOp returns another object that is the result of a given binary operator and a right-hand side object.

func (*Float) Copy 

func (o *Float) Copy() Object

Copy returns a copy of the type.

func (*Float) Equals 

func (o *Float) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Float) IsFalsy 

func (o *Float) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Float) String 

func (o *Float) String() string

func (*Float) TypeName 

func (o *Float) TypeName() string

TypeName returns the name of the type.

type ImmutableArray 

type ImmutableArray struct {
	ObjectImpl
	Value []Object
}

ImmutableArray represents an immutable array of objects.

func (*ImmutableArray) BinaryOp 

func (o *ImmutableArray) BinaryOp(op token.Token, rhs Object) (Object, error)

BinaryOp returns another object that is the result of a given binary operator and a right-hand side object.

func (*ImmutableArray) CanIterate 

func (o *ImmutableArray) CanIterate() bool

CanIterate returns whether the Object can be Iterated.

func (*ImmutableArray) Copy 

func (o *ImmutableArray) Copy() Object

Copy returns a copy of the type.

func (*ImmutableArray) Equals 

func (o *ImmutableArray) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*ImmutableArray) IndexGet 

func (o *ImmutableArray) IndexGet(index Object) (res Object, err error)

IndexGet returns an element at a given index.

func (*ImmutableArray) IsFalsy 

func (o *ImmutableArray) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*ImmutableArray) Iterate 

func (o *ImmutableArray) Iterate() Iterator

Iterate creates an array iterator.

func (*ImmutableArray) String 

func (o *ImmutableArray) String() string

func (*ImmutableArray) TypeName 

func (o *ImmutableArray) TypeName() string

TypeName returns the name of the type.

type ImmutableMap 

type ImmutableMap struct {
	ObjectImpl
	Value map[string]Object
}

ImmutableMap represents an immutable map object.

func (*ImmutableMap) CanIterate 

func (o *ImmutableMap) CanIterate() bool

CanIterate returns whether the Object can be Iterated.

func (*ImmutableMap) Copy 

func (o *ImmutableMap) Copy() Object

Copy returns a copy of the type.

func (*ImmutableMap) Equals 

func (o *ImmutableMap) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*ImmutableMap) IndexGet 

func (o *ImmutableMap) IndexGet(index Object) (res Object, err error)

IndexGet returns the value for the given key.

func (*ImmutableMap) IsFalsy 

func (o *ImmutableMap) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*ImmutableMap) Iterate 

func (o *ImmutableMap) Iterate() Iterator

Iterate creates an immutable map iterator.

func (*ImmutableMap) String 

func (o *ImmutableMap) String() string

func (*ImmutableMap) TypeName 

func (o *ImmutableMap) TypeName() string

TypeName returns the name of the type.

type Importable 

type Importable interface {
	// Import should return either an Object or module source code ([]byte).
	Import(moduleName string) (interface{}, error)
}

Importable interface represents importable module instance.

type Int 

type Int struct {
	ObjectImpl
	Value int64
}

Int represents an integer value.

func (*Int) BinaryOp 

func (o *Int) BinaryOp(op token.Token, rhs Object) (Object, error)

BinaryOp returns another object that is the result of a given binary operator and a right-hand side object.

func (*Int) Copy 

func (o *Int) Copy() Object

Copy returns a copy of the type.

func (*Int) Equals 

func (o *Int) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Int) IsFalsy 

func (o *Int) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Int) String 

func (o *Int) String() string

func (*Int) TypeName 

func (o *Int) TypeName() string

TypeName returns the name of the type.

type Iterator 

type Iterator interface {
	Object

	// Next returns true if there are more elements to iterate.
	Next() bool

	// Key returns the key or index value of the current element.
	Key() Object

	// Value returns the value of the current element.
	Value() Object
}

Iterator represents an iterator for underlying data type.

type Map 

type Map struct {
	ObjectImpl
	Value map[string]Object
}

Map represents a map of objects.

func (*Map) CanIterate 

func (o *Map) CanIterate() bool

CanIterate returns whether the Object can be Iterated.

func (*Map) Copy 

func (o *Map) Copy() Object

Copy returns a copy of the type.

func (*Map) Equals 

func (o *Map) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Map) IndexGet 

func (o *Map) IndexGet(index Object) (res Object, err error)

IndexGet returns the value for the given key.

func (*Map) IndexSet 

func (o *Map) IndexSet(index, value Object) (err error)

IndexSet sets the value for the given key.

func (*Map) IsFalsy 

func (o *Map) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Map) Iterate 

func (o *Map) Iterate() Iterator

Iterate creates a map iterator.

func (*Map) String 

func (o *Map) String() string

func (*Map) TypeName 

func (o *Map) TypeName() string

TypeName returns the name of the type.

type MapIterator 

type MapIterator struct {
	ObjectImpl
	// contains filtered or unexported fields
}

MapIterator represents an iterator for the map.

func (*MapIterator) Copy 

func (i *MapIterator) Copy() Object

Copy returns a copy of the type.

func (*MapIterator) Equals 

func (i *MapIterator) Equals(Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*MapIterator) IsFalsy 

func (i *MapIterator) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*MapIterator) Key 

func (i *MapIterator) Key() Object

Key returns the key or index value of the current element.

func (*MapIterator) Next 

func (i *MapIterator) Next() bool

Next returns true if there are more elements to iterate.

func (*MapIterator) String 

func (i *MapIterator) String() string

func (*MapIterator) TypeName 

func (i *MapIterator) TypeName() string

TypeName returns the name of the type.

func (*MapIterator) Value 

func (i *MapIterator) Value() Object

Value returns the value of the current element.

type ModuleMap 

type ModuleMap struct {
	// contains filtered or unexported fields
}

ModuleMap represents a set of named modules. Use NewModuleMap to create a new module map.

func NewModuleMap 

func NewModuleMap() *ModuleMap

NewModuleMap creates a new module map.

func (*ModuleMap) Add 

func (m *ModuleMap) Add(name string, module Importable)

Add adds an import module.

func (*ModuleMap) AddBuiltinModule 

func (m *ModuleMap) AddBuiltinModule(name string, attrs map[string]Object)

AddBuiltinModule adds a builtin module.

func (*ModuleMap) AddMap 

func (m *ModuleMap) AddMap(o *ModuleMap)

AddMap adds named modules from another module map.

func (*ModuleMap) AddSourceModule 

func (m *ModuleMap) AddSourceModule(name string, src []byte)

AddSourceModule adds a source module.

func (*ModuleMap) Copy 

func (m *ModuleMap) Copy() *ModuleMap

Copy creates a copy of the module map.

func (*ModuleMap) Get 

func (m *ModuleMap) Get(name string) Importable

Get returns an import module identified by name. It returns if the name is not found.

func (*ModuleMap) GetBuiltinModule 

func (m *ModuleMap) GetBuiltinModule(name string) *BuiltinModule

GetBuiltinModule returns a builtin module identified by name. It returns if the name is not found or the module is not a builtin module.

func (*ModuleMap) GetSourceModule 

func (m *ModuleMap) GetSourceModule(name string) *SourceModule

GetSourceModule returns a source module identified by name. It returns if the name is not found or the module is not a source module.

func (*ModuleMap) Len 

func (m *ModuleMap) Len() int

Len returns the number of named modules.

func (*ModuleMap) Remove 

func (m *ModuleMap) Remove(name string)

Remove removes a named module.

type Object 

type Object interface {
	// TypeName should return the name of the type.
	TypeName() string

	// String should return a string representation of the type's value.
	String() string

	// BinaryOp should return another object that is the result of a given
	// binary operator and a right-hand side object. If BinaryOp returns an
	// error, the VM will treat it as a run-time error.
	BinaryOp(op token.Token, rhs Object) (Object, error)

	// IsFalsy should return true if the value of the type should be considered
	// as falsy.
	IsFalsy() bool

	// Equals should return true if the value of the type should be considered
	// as equal to the value of another object.
	Equals(another Object) bool

	// Copy should return a copy of the type (and its value). Copy function
	// will be used for copy() builtin function which is expected to deep-copy
	// the values generally.
	Copy() Object

	// IndexGet should take an index Object and return a result Object or an
	// error for indexable objects. Indexable is an object that can take an
	// index and return an object. If error is returned, the runtime will treat
	// it as a run-time error and ignore returned value. If Object is not
	// indexable, ErrNotIndexable should be returned as error. If nil is
	// returned as value, it will be converted to UndefinedToken value by the
	// runtime.
	IndexGet(index Object) (value Object, err error)

	// IndexSet should take an index Object and a value Object for index
	// assignable objects. Index assignable is an object that can take an index
	// and a value on the left-hand side of the assignment statement. If Object
	// is not index assignable, ErrNotIndexAssignable should be returned as
	// error. If an error is returned, it will be treated as a run-time error.
	IndexSet(index, value Object) error

	// Iterate should return an Iterator for the type.
	Iterate() Iterator

	// CanIterate should return whether the Object can be Iterated.
	CanIterate() bool

	// Call should take an arbitrary number of arguments and returns a return
	// value and/or an error, which the VM will consider as a run-time error.
	Call(ctx context.Context, args ...Object) (ret Object, err error)

	// CanCall should return whether the Object can be Called.
	CanCall() bool
}

Object represents an object in the VM. 

var (
	// TrueValue represents a true value.
	TrueValue Object = &Bool{value: true}

	// FalseValue represents a false value.
	FalseValue Object = &Bool{value: false}

	// UndefinedValue represents an undefined value.
	UndefinedValue Object = &Undefined{}
)

func FromInterface 

func FromInterface(v interface{}) (Object, error)

FromInterface will attempt to convert an interface{} v to a vvm Object

func MakeObject added in v0.4.0 

func MakeObject(code byte) Object

MakeObject creates a new object based on the given type code.

func UnmarshalObject added in v0.4.0 

func UnmarshalObject(nn int, b []byte) (n int, o Object, err error)

UnmarshalObject unmarshals the given byte slice into an object.

type ObjectImpl 

type ObjectImpl struct {
}

ObjectImpl represents a default Object Implementation. To defined a new value type, one can embed ObjectImpl in their type declarations to avoid implementing all non-significant methods. TypeName() and String() methods still need to be implemented.

func (*ObjectImpl) BinaryOp 

func (o *ObjectImpl) BinaryOp(_ token.Token, _ Object) (Object, error)

BinaryOp returns another object that is the result of a given binary operator and a right-hand side object.

func (*ObjectImpl) Call 

func (o *ObjectImpl) Call(_ context.Context, _ ...Object) (ret Object, err error)

Call takes an arbitrary number of arguments and returns a return value and/or an error.

func (*ObjectImpl) CanCall 

func (o *ObjectImpl) CanCall() bool

CanCall returns whether the Object can be Called.

func (*ObjectImpl) CanIterate 

func (o *ObjectImpl) CanIterate() bool

CanIterate returns whether the Object can be Iterated.

func (*ObjectImpl) Copy 

func (o *ObjectImpl) Copy() Object

Copy returns a copy of the type.

func (*ObjectImpl) Equals 

func (o *ObjectImpl) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*ObjectImpl) IndexGet 

func (o *ObjectImpl) IndexGet(_ Object) (res Object, err error)

IndexGet returns an element at a given index.

func (*ObjectImpl) IndexSet 

func (o *ObjectImpl) IndexSet(_, _ Object) (err error)

IndexSet sets an element at a given index.

func (*ObjectImpl) IsFalsy 

func (o *ObjectImpl) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*ObjectImpl) Iterate 

func (o *ObjectImpl) Iterate() Iterator

Iterate returns an iterator.

func (*ObjectImpl) String 

func (o *ObjectImpl) String() string

func (*ObjectImpl) TypeName 

func (o *ObjectImpl) TypeName() string

TypeName returns the name of the type.

type ObjectPtr 

type ObjectPtr struct {
	ObjectImpl
	Value *Object
}

ObjectPtr represents a free variable.

func (*ObjectPtr) Copy 

func (o *ObjectPtr) Copy() Object

Copy returns a copy of the type.

func (*ObjectPtr) Equals 

func (o *ObjectPtr) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*ObjectPtr) IsFalsy 

func (o *ObjectPtr) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*ObjectPtr) String 

func (o *ObjectPtr) String() string

func (*ObjectPtr) TypeName 

func (o *ObjectPtr) TypeName() string

TypeName returns the name of the type.

type SourceModule 

type SourceModule struct {
	Src []byte
}

SourceModule is an importable module that's written in vvm.

func (*SourceModule) Import 

func (m *SourceModule) Import(_ string) (interface{}, error)

Import returns a module source code.

type String 

type String struct {
	ObjectImpl
	Value string
	// contains filtered or unexported fields
}

String represents a string value.

func (*String) BinaryOp 

func (o *String) BinaryOp(op token.Token, rhs Object) (Object, error)

BinaryOp returns another object that is the result of a given binary operator and a right-hand side object.

func (*String) CanIterate 

func (o *String) CanIterate() bool

CanIterate returns whether the Object can be Iterated.

func (*String) Copy 

func (o *String) Copy() Object

Copy returns a copy of the type.

func (*String) Equals 

func (o *String) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*String) IndexGet 

func (o *String) IndexGet(index Object) (res Object, err error)

IndexGet returns a character at a given index.

func (*String) IsFalsy 

func (o *String) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*String) Iterate 

func (o *String) Iterate() Iterator

Iterate creates a string iterator.

func (*String) String 

func (o *String) String() string

func (*String) TypeName 

func (o *String) TypeName() string

TypeName returns the name of the type.

type StringIterator 

type StringIterator struct {
	ObjectImpl
	// contains filtered or unexported fields
}

StringIterator represents an iterator for a string.

func (*StringIterator) Copy 

func (i *StringIterator) Copy() Object

Copy returns a copy of the type.

func (*StringIterator) Equals 

func (i *StringIterator) Equals(Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*StringIterator) IsFalsy 

func (i *StringIterator) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*StringIterator) Key 

func (i *StringIterator) Key() Object

Key returns the key or index value of the current element.

func (*StringIterator) Next 

func (i *StringIterator) Next() bool

Next returns true if there are more elements to iterate.

func (*StringIterator) String 

func (i *StringIterator) String() string

func (*StringIterator) TypeName 

func (i *StringIterator) TypeName() string

TypeName returns the name of the type.

func (*StringIterator) Value 

func (i *StringIterator) Value() Object

Value returns the value of the current element.

type Symbol 

type Symbol struct {
	Name          string
	Scope         SymbolScope
	Index         int
	LocalAssigned bool // if the local symbol is assigned at least once
}

Symbol represents a symbol in the symbol table.

type SymbolScope 

type SymbolScope string

SymbolScope represents a symbol scope. 

const (
	ScopeGlobal  SymbolScope = "GLOBAL"
	ScopeLocal   SymbolScope = "LOCAL"
	ScopeBuiltin SymbolScope = "BUILTIN"
	ScopeFree    SymbolScope = "FREE"
)

List of symbol scopes

type SymbolTable 

type SymbolTable struct {
	// contains filtered or unexported fields
}

SymbolTable represents a symbol table.

func NewSymbolTable 

func NewSymbolTable() *SymbolTable

NewSymbolTable creates a SymbolTable.

func (*SymbolTable) BuiltinSymbols 

func (t *SymbolTable) BuiltinSymbols() []*Symbol

BuiltinSymbols returns builtin symbols for the scope.

func (*SymbolTable) Define 

func (t *SymbolTable) Define(name string) *Symbol

Define adds a new symbol in the current scope.

func (*SymbolTable) DefineBuiltin 

func (t *SymbolTable) DefineBuiltin(index int, name string) *Symbol

DefineBuiltin adds a symbol for builtin function.

func (*SymbolTable) Fork 

func (t *SymbolTable) Fork(block bool) *SymbolTable

Fork creates a new symbol table for a new scope.

func (*SymbolTable) FreeSymbols 

func (t *SymbolTable) FreeSymbols() []*Symbol

FreeSymbols returns free symbols for the scope.

func (*SymbolTable) MaxSymbols 

func (t *SymbolTable) MaxSymbols() int

MaxSymbols returns the total number of symbols defined in the scope.

func (*SymbolTable) Names 

func (t *SymbolTable) Names() []string

Names returns the name of all the symbols.

func (*SymbolTable) Parent 

func (t *SymbolTable) Parent(skipBlock bool) *SymbolTable

Parent returns the outer scope of the current symbol table.

func (*SymbolTable) Resolve 

func (t *SymbolTable) Resolve(name string, recur bool) (*Symbol, int, bool)

Resolve resolves a symbol with a given name.

type Time 

type Time struct {
	ObjectImpl
	Value time.Time
}

Time represents a time value.

func (*Time) BinaryOp 

func (o *Time) BinaryOp(op token.Token, rhs Object) (Object, error)

BinaryOp returns another object that is the result of a given binary operator and a right-hand side object.

func (*Time) Copy 

func (o *Time) Copy() Object

Copy returns a copy of the type.

func (*Time) Equals 

func (o *Time) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Time) IsFalsy 

func (o *Time) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Time) String 

func (o *Time) String() string

func (*Time) TypeName 

func (o *Time) TypeName() string

TypeName returns the name of the type.

type Undefined 

type Undefined struct {
	ObjectImpl
}

Undefined represents an undefined value.

func (*Undefined) CanIterate 

func (o *Undefined) CanIterate() bool

CanIterate returns whether the Object can be Iterated.

func (*Undefined) Copy 

func (o *Undefined) Copy() Object

Copy returns a copy of the type.

func (*Undefined) Equals 

func (o *Undefined) Equals(x Object) bool

Equals returns true if the value of the type is equal to the value of another object.

func (*Undefined) IndexGet 

func (o *Undefined) IndexGet(_ Object) (Object, error)

IndexGet returns an element at a given index.

func (*Undefined) IsFalsy 

func (o *Undefined) IsFalsy() bool

IsFalsy returns true if the value of the type is falsy.

func (*Undefined) Iterate 

func (o *Undefined) Iterate() Iterator

Iterate creates a map iterator.

func (*Undefined) Key 

func (o *Undefined) Key() Object

Key returns the key or index value of the current element.

func (*Undefined) Next 

func (o *Undefined) Next() bool

Next returns true if there are more elements to iterate.

func (*Undefined) String 

func (o *Undefined) String() string

func (*Undefined) TypeName 

func (o *Undefined) TypeName() string

TypeName returns the name of the type.

func (*Undefined) Value 

func (o *Undefined) Value() Object

Value returns the value of the current element.

type VM 

type VM struct {
	In   io.Reader
	Out  io.Writer
	Args []string
	// contains filtered or unexported fields
}

VM is a virtual machine that executes the bytecode compiled by Compiler.

func NewVM 

func NewVM(ctx context.Context, bytecode *Bytecode, globals []Object, maxAllocs int64) *VM

NewVM creates a VM.

func (*VM) Abort 

func (v *VM) Abort()

Abort aborts the execution of current VM and all its descendant VMs.

func (*VM) IsStackEmpty 

func (v *VM) IsStackEmpty() bool

IsStackEmpty tests if the stack is empty or not.

func (*VM) Run 

func (v *VM) Run() (err error)

Run starts the execution.

func (*VM) RunCompiled 

func (v *VM) RunCompiled(fn *CompiledFunction, args ...Object) (val Object, err error)

RunCompiled run the VM with user supplied function fn.

func (*VM) ShallowClone 

func (v *VM) ShallowClone() *VM

ShallowClone creates a shallow copy of the current VM, with separate stack and frame. The copy shares the underlying globals, constants with the original. ShallowClone is typically followed by RunCompiled to run user supplied compiled function.

Source Files

View all Source files

Directories

Path Synopsis
Package encoding provides functions to marshal and unmarshal data types.
 Package encoding provides functions to marshal and unmarshal data types.
json

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