builtins

Documentation

Overview

Package builtins contains utilities for implementing built-in functions.

Index

• func FloatToNumber(f *big.Float) ast.Number
• func IntOperand(x ast.Value, pos int) (int, error)
• 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 SetOperand(x ast.Value, pos int) (*ast.Set, error)
• func StringOperand(x ast.Value, pos int) (ast.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

Functions

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 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 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.

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