value

Documentation

Overview

Package value defines the type that represents the evaluation result.

Index

• Variables
• type FunctionData
• type Type
  • func NewArray(a []Type) Type
  • func NewBool(b bool) Type
  • func NewFloat(f float64) Type
  • func NewFunction(node int, frame *[]Type, paramCnt int, localCnt int) Type
  • func NewInt(i int) Type
  • func NewString(s string) Type
  • func (t Type) Abbrev() string
  • func (t Type) Arith(op bytecode.OpCode, b Type) (Type, error)
  • func (t Type) Display() string
  • func (t Type) Eq(op bytecode.OpCode, b Type) (Type, error)
  • func (t Type) Flip() (Type, error)
  • func (t Type) Index(b ...Type) (Type, error)
  • func (t Type) IsNil() bool
  • func (t Type) Len() (Type, error)
  • func (t Type) Logic(op bytecode.OpCode, b Type) (Type, error)
  • func (t Type) Mod(b Type) (Type, error)
  • func (t Type) Not() (Type, error)
  • func (t Type) Relational(op bytecode.OpCode, b Type) (Type, error)
  • func (t *Type) SetFrame(frame *[]Type)
  • func (t Type) Shift(op bytecode.OpCode, b Type) (Type, error)
  • func (t *Type) StrictEq(b Type) bool
  • func (t Type) String() string
  • func (t Type) ToArray() ([]Type, bool)
  • func (t Type) ToBool() (bool, bool)
  • func (t Type) ToFunction() (FunctionData, bool)
  • func (t Type) ToInt() (int, bool)
  • func (t Type) ToString() (string, bool)
  • func (t *Type) WeakEq(b Type) (bool, error)

Variables

var (
	ErrNil     = errors.New("nil error")
	ErrType    = errors.New("type error")
	ErrZeroDiv = errors.New("division by zero")
	ErrIndex   = errors.New("index error")
)

Predefined errors.

var Nil = Type{/* contains filtered or unexported fields */}

Nil is the nil value.

Types

type FunctionData

type FunctionData struct {
	Node     int     // Pointer to the code of the function - the AST node that holds the function
	Frame    *[]Type // Pointer to the closure stack frame
	ParamCnt int     // ParamCnt is the number of parameters of the function
	LocalCnt int     // LocalCnt is the number of local variables of the function including ParamCnt
}

A structure that represents a function value.

type Type

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

Type is evaluation result value.

It is a uniform structure, not an interface, to keep evaluation on the stack as much as possible.

func NewArray

func NewArray(a []Type) Type

NewArray allocates a new array value.

func NewBool

func NewBool(b bool) Type

NewBool allocates a new bool value.

func NewFloat

func NewFloat(f float64) Type

NewFloat allocates a new float value.

func NewFunction

func NewFunction(node int, frame *[]Type, paramCnt int, localCnt int) Type

NewFunction allocates a new function value.

func NewInt

func NewInt(i int) Type

NewInt allocates a new int value.

func NewString

func NewString(s string) Type

NewString allocates a new string value.

func (Type) Abbrev

func (t Type) Abbrev() string

Abbrev abbreviates string of t to 20 characters with ellipses.

func (Type) Arith

func (t Type) Arith(op bytecode.OpCode, b Type) (Type, error)

Arith is value arithmetics, +, -, * /.

func (Type) Display

func (t Type) Display() string

Display converts a value to a string for calc result printing.

Adds extra quotes around string type.

func (Type) Eq

func (t Type) Eq(op bytecode.OpCode, b Type) (Type, error)

Equality check, ==, !=.

func (Type) Flip

func (t Type) Flip() (Type, error)

Flip is integer bit flip operator.

func (Type) Index

func (t Type) Index(b ...Type) (Type, error)

Index is value indexing, [] and [:].

func (Type) IsNil

func (t Type) IsNil() bool

IsNil determines whether a value is nil.

func (Type) Len

func (t Type) Len() (Type, error)

Len is value length.

func (Type) Logic

func (t Type) Logic(op bytecode.OpCode, b Type) (Type, error)

Logic is value logic ops &, |.

func (Type) Mod

func (t Type) Mod(b Type) (Type, error)

func (Type) Not

func (t Type) Not() (Type, error)

Not is boolean not operator.

func (Type) Relational

func (t Type) Relational(op bytecode.OpCode, b Type) (Type, error)

Relational is value relational <, >, <= ...

func (*Type) SetFrame

func (t *Type) SetFrame(frame *[]Type)

func (Type) Shift

func (t Type) Shift(op bytecode.OpCode, b Type) (Type, error)

Shift is bit shift ops <<, >>.

func (*Type) StrictEq

func (t *Type) StrictEq(b Type) bool

StrictEq decides whether a and b are exactly the same value.

1 == 1.0 -> false

in strict equality all functions are equal, this is counter intuitive, but for testing it makes sense.

func (Type) String

func (t Type) String() string

String converts any value.Type to string.

func (Type) ToArray

func (t Type) ToArray() ([]Type, bool)

func (Type) ToBool

func (t Type) ToBool() (bool, bool)

ToBool converts a value to bool.

It returns ok false if not an bool.

func (Type) ToFunction

func (t Type) ToFunction() (FunctionData, bool)

ToFunction converts a value to FunctionData.

It returns ok false if not a function.

func (Type) ToInt

func (t Type) ToInt() (int, bool)

ToInt converts a value to int.

It returns ok false if not an int.

func (Type) ToString

func (t Type) ToString() (string, bool)

ToString converts a value to string.

It returns ok false if not a string.

func (*Type) WeakEq

func (t *Type) WeakEq(b Type) (bool, error)

WeakEq decides whether a and b are the same value as per language rules.

1 == 1.0 -> true

All functions are un-equal.