tengo

package
v0.0.0-...-79aaa6a Latest Latest
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 Go to latest Published: Mar 8, 2021 License: MIT, MIT Imports: 20 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")
)
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 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.

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) GobDecode 

func (o *Bool) GobDecode(b []byte) (err error)

GobDecode decodes bool value from input bytes.

func (*Bool) GobEncode 

func (o *Bool) GobEncode() (b []byte, err error)

GobEncode encodes bool values into bytes.

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(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) Decode 

func (b *Bytecode) Decode(r io.Reader, modules *ModuleMap) error

Decode reads Bytecode data from the reader.

func (*Bytecode) Encode 

func (b *Bytecode) Encode(w io.Writer) error

Encode writes Bytecode data to the writer.

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) RemoveDuplicates 

func (b *Bytecode) RemoveDuplicates()

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

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(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 Compiled 

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

Compiled is a compiled instance of the user script. Use Script.Compile() to create Compiled object.

func (*Compiled) Clone 

func (c *Compiled) Clone() *Compiled

Clone creates a new copy of Compiled. Cloned copies are safe for concurrent use by multiple goroutines.

func (*Compiled) Get 

func (c *Compiled) Get(name string) *Variable

Get returns a variable identified by the name.

func (*Compiled) GetAll 

func (c *Compiled) GetAll() []*Variable

GetAll returns all the variables that are defined by the compiled script.

func (*Compiled) IsDefined 

func (c *Compiled) IsDefined(name string) bool

IsDefined returns true if the variable name is defined (has value) before or after the execution.

func (*Compiled) Run 

func (c *Compiled) Run() error

Run executes the compiled script in the virtual machine.

func (*Compiled) RunContext 

func (c *Compiled) RunContext(ctx context.Context) (err error)

RunContext is like Run but includes a context.

func (*Compiled) Set 

func (c *Compiled) Set(name string, value interface{}) error

Set replaces the value of a global variable identified by the name. An error will be returned if the name was not defined during compilation.

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
	// contains filtered or unexported fields
}

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 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 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(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 Tengo 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(_ ...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 Script 

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

Script can simplify compilation and execution of embedded scripts.

func NewScript 

func NewScript(input []byte) *Script

NewScript creates a Script instance with an input script.

func (*Script) Add 

func (s *Script) Add(name string, value interface{}) error

Add adds a new variable or updates an existing variable to the script.

func (*Script) Compile 

func (s *Script) Compile() (*Compiled, error)

Compile compiles the script with all the defined variables, and, returns Compiled object.

func (*Script) EnableFileImport 

func (s *Script) EnableFileImport(enable bool)

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

func (*Script) Remove 

func (s *Script) Remove(name string) bool

Remove removes (undefines) an existing variable for the script. It returns false if the variable name is not defined.

func (*Script) Run 

func (s *Script) Run() (compiled *Compiled, err error)

Run compiles and runs the scripts. Use returned compiled object to access global variables.

func (*Script) RunContext 

func (s *Script) RunContext(
	ctx context.Context,
) (compiled *Compiled, err error)

RunContext is like Run but includes a context.

func (*Script) SetImportDir 

func (s *Script) SetImportDir(dir string) error

SetImportDir sets the initial import directory for script files.

func (*Script) SetImports 

func (s *Script) SetImports(modules *ModuleMap)

SetImports sets import modules.

func (*Script) SetMaxAllocs 

func (s *Script) SetMaxAllocs(n int64)

SetMaxAllocs sets the maximum number of objects allocations during the run time. Compiled script will return ErrObjectAllocLimit error if it exceeds this limit.

func (*Script) SetMaxConstObjects 

func (s *Script) SetMaxConstObjects(n int)

SetMaxConstObjects sets the maximum number of objects in the compiled constants.

type SourceModule 

type SourceModule struct {
	Src []byte
}

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

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 UserFunction 

type UserFunction struct {
	ObjectImpl
	Name       string
	Value      CallableFunc
	EncodingID string
}

UserFunction represents a user function.

func (*UserFunction) Call 

func (o *UserFunction) Call(args ...Object) (Object, error)

Call invokes a user function.

func (*UserFunction) CanCall 

func (o *UserFunction) CanCall() bool

CanCall returns whether the Object can be Called.

func (*UserFunction) Copy 

func (o *UserFunction) Copy() Object

Copy returns a copy of the type.

func (*UserFunction) Equals 

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

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

func (*UserFunction) String 

func (o *UserFunction) String() string

func (*UserFunction) TypeName 

func (o *UserFunction) TypeName() string

TypeName returns the name of the type.

type VM 

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

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

func NewVM 

func NewVM(
	bytecode *Bytecode,
	globals []Object,
	maxAllocs int64,
) *VM

NewVM creates a VM.

func (*VM) Abort 

func (v *VM) Abort()

Abort aborts the execution.

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.

type Variable 

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

Variable is a user-defined variable for the script.

func NewVariable 

func NewVariable(name string, value interface{}) (*Variable, error)

NewVariable creates a Variable.

func (*Variable) Array 

func (v *Variable) Array() []interface{}

Array returns []interface value of the variable value. It returns 0 if the value is not convertible to []interface.

func (*Variable) Bool 

func (v *Variable) Bool() bool

Bool returns bool value of the variable value. It returns 0 if the value is not convertible to bool.

func (*Variable) Bytes 

func (v *Variable) Bytes() []byte

Bytes returns a byte slice of the variable value. It returns nil if the value is not convertible to byte slice.

func (*Variable) Char 

func (v *Variable) Char() rune

Char returns rune value of the variable value. It returns 0 if the value is not convertible to rune.

func (*Variable) Error 

func (v *Variable) Error() error

Error returns an error if the underlying value is error object. If not, this returns nil.

func (*Variable) Float 

func (v *Variable) Float() float64

Float returns float64 value of the variable value. It returns 0.0 if the value is not convertible to float64.

func (*Variable) Int 

func (v *Variable) Int() int

Int returns int value of the variable value. It returns 0 if the value is not convertible to int.

func (*Variable) Int64 

func (v *Variable) Int64() int64

Int64 returns int64 value of the variable value. It returns 0 if the value is not convertible to int64.

func (*Variable) IsUndefined 

func (v *Variable) IsUndefined() bool

IsUndefined returns true if the underlying value is undefined.

func (*Variable) Map 

func (v *Variable) Map() map[string]interface{}

Map returns map[string]interface{} value of the variable value. It returns 0 if the value is not convertible to map[string]interface{}.

func (*Variable) Name 

func (v *Variable) Name() string

Name returns the name of the variable.

func (*Variable) Object 

func (v *Variable) Object() Object

Object returns an underlying Object of the variable value. Note that returned Object is a copy of an actual Object used in the script.

func (*Variable) String 

func (v *Variable) String() string

String returns string value of the variable value. It returns 0 if the value is not convertible to string.

func (*Variable) Value 

func (v *Variable) Value() interface{}

Value returns an empty interface of the variable value.

func (*Variable) ValueType 

func (v *Variable) ValueType() string

ValueType returns the name of the value type.

Source Files

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Directories

Path Synopsis
json
test0

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