builtins

Documentation

Overview

Package builtins contains utilities for implementing built-in functions.

Index

• func ArrayOperand(x ast.Value, pos int) (*ast.Array, error)
• func BigIntOperand(x ast.Value, pos int) (*big.Int, error)
• func FloatToNumber(f *big.Float) ast.Number
• func IntOperand(x ast.Value, pos int) (int, error)
• func IntToNumber(i *big.Int) ast.Number
• func NewOperandElementErr(pos int, composite ast.Value, got ast.Value, expected ...string) error
• func NewOperandEnumErr(pos int, expected ...string) error
• func NewOperandErr(pos int, f string, a ...interface{}) error
• func NewOperandTypeErr(pos int, got ast.Value, expected ...string) error
• func NumberOperand(x ast.Value, pos int) (ast.Number, error)
• func NumberToFloat(n ast.Number) *big.Float
• func NumberToInt(n ast.Number) (*big.Int, error)
• func ObjectOperand(x ast.Value, pos int) (ast.Object, error)
• func RuneSliceOperand(x ast.Value, pos int) ([]rune, error)
• func SetOperand(x ast.Value, pos int) (ast.Set, error)
• func StringOperand(x ast.Value, pos int) (ast.String, error)
• func StringSliceOperand(a ast.Value, pos int) ([]string, error)
• type Cache
  • func (c Cache) Get(k interface{}) (interface{}, bool)
  • func (c Cache) Put(k, v interface{})
• type ErrOperand
  • func (err ErrOperand) Error() string
• type NDBCache
  • func (c NDBCache) AsValue() ast.Value
  • func (c NDBCache) Get(name string, k ast.Value) (ast.Value, bool)
  • func (c NDBCache) MarshalJSON() ([]byte, error)
  • func (c NDBCache) Put(name string, k, v ast.Value)
  • func (c *NDBCache) UnmarshalJSON(data []byte) error

Functions

func ArrayOperand

func ArrayOperand(x ast.Value, pos int) (*ast.Array, error)

ArrayOperand converts x to an array. If the cast fails, a descriptive error is returned.

func BigIntOperand

func BigIntOperand(x ast.Value, pos int) (*big.Int, error)

BigIntOperand converts x to a big int. If the cast fails, a descriptive error is returned.

func FloatToNumber

func FloatToNumber(f *big.Float) ast.Number

FloatToNumber converts f to a number.

func IntOperand

func IntOperand(x ast.Value, pos int) (int, error)

IntOperand converts x to an int. If the cast fails, a descriptive error is returned.

func IntToNumber

func IntToNumber(i *big.Int) ast.Number

IntToNumber converts i to a number.

func NewOperandElementErr

func NewOperandElementErr(pos int, composite ast.Value, got ast.Value, expected ...string) error

NewOperandElementErr returns an operand error indicating an element in the composite operand was wrong.

func NewOperandEnumErr

func NewOperandEnumErr(pos int, expected ...string) error

NewOperandEnumErr returns an operand error indicating a value was wrong.

func NewOperandErr

func NewOperandErr(pos int, f string, a ...interface{}) error

NewOperandErr returns a generic operand error.

func NewOperandTypeErr

func NewOperandTypeErr(pos int, got ast.Value, expected ...string) error

NewOperandTypeErr returns an operand error indicating the operand's type was wrong.

func NumberOperand

func NumberOperand(x ast.Value, pos int) (ast.Number, error)

NumberOperand converts x to a number. If the cast fails, a descriptive error is returned.

func NumberToFloat

func NumberToFloat(n ast.Number) *big.Float

NumberToFloat converts n to a big float.

func NumberToInt

func NumberToInt(n ast.Number) (*big.Int, error)

NumberToInt converts n to a big int. If n cannot be converted to an big int, an error is returned.

func ObjectOperand

func ObjectOperand(x ast.Value, pos int) (ast.Object, error)

ObjectOperand converts x to an object. If the cast fails, a descriptive error is returned.

func RuneSliceOperand

func RuneSliceOperand(x ast.Value, pos int) ([]rune, error)

RuneSliceOperand converts x to a []rune. If the cast fails, a descriptive error is returned.

func SetOperand

func SetOperand(x ast.Value, pos int) (ast.Set, error)

SetOperand converts x to a set. If the cast fails, a descriptive error is returned.

func StringOperand

func StringOperand(x ast.Value, pos int) (ast.String, error)

StringOperand converts x to a string. If the cast fails, a descriptive error is returned.

func StringSliceOperand

func StringSliceOperand(a ast.Value, pos int) ([]string, error)

StringSliceOperand converts x to a []string. If the cast fails, a descriptive error is returned.

Types

type Cache

type Cache map[interface{}]interface{}

Cache defines the built-in cache used by the top-down evaluation. The keys must be comparable and should not be of type string.

func (Cache) Get

func (c Cache) Get(k interface{}) (interface{}, bool)

Get returns the cached value for k.

func (Cache) Put

func (c Cache) Put(k, v interface{})

Put updates the cache for the named built-in.

type ErrOperand

type ErrOperand string

ErrOperand represents an invalid operand has been passed to a built-in function. Built-ins should return ErrOperand to indicate a type error has occurred.

func (ErrOperand) Error

func (err ErrOperand) Error() string

type NDBCache

type NDBCache map[string]ast.Object

We use an ast.Object for the cached keys/values because a naive map[ast.Value]ast.Value will not correctly detect value equality of the member keys.

func (NDBCache) AsValue

func (c NDBCache) AsValue() ast.Value

func (NDBCache) Get

func (c NDBCache) Get(name string, k ast.Value) (ast.Value, bool)

Get returns the cached value for k for the named builtin.

func (NDBCache) MarshalJSON

func (c NDBCache) MarshalJSON() ([]byte, error)

Convenience functions for serializing the data structure.

func (NDBCache) Put

func (c NDBCache) Put(name string, k, v ast.Value)

Put updates the cache for the named built-in. Automatically creates the 2-level hierarchy as needed.

func (*NDBCache) UnmarshalJSON

func (c *NDBCache) UnmarshalJSON(data []byte) error