expr

Documentation

Index

• func AddFunction(name string, handler func(params ...any) (any, error))
• func AvailableFunctions() []string
• func Compile(input string, ops ...Option) (*vm.Program, error)
• func Eval(input string, env any) (any, error)
• func Parse(expr string) (*vm.Program, error)
• func Run(program *vm.Program, env any) (any, error)
• type Option
  • func AllowUndefinedVariables() Option
  • func AsAny() Option
  • func AsBool() Option
  • func AsFloat64() Option
  • func AsInt() Option
  • func AsInt64() Option
  • func AsKind(kind reflect.Kind) Option
  • func ConstExpr(fn string) Option
  • func DisableAllBuiltins() Option
  • func DisableBuiltin(name string) Option
  • func EnableBuiltin(name string) Option
  • func Env(env any) Option
  • func Function(name string, fn func(params ...any) (any, error), types ...any) Option
  • func Operator(operator string, fn ...string) Option
  • func Optimize(b bool) Option
  • func Patch(visitor ast.Visitor) Option

Functions

func AddFunction

func AddFunction(name string, handler func(params ...any) (any, error))

func AvailableFunctions

func AvailableFunctions() []string

func Compile

func Compile(input string, ops ...Option) (*vm.Program, error)

Compile parses and compiles given input expression to bytecode program.

func Eval

func Eval(input string, env any) (any, error)

Eval parses, compiles and runs given input.

func Parse

func Parse(expr string) (*vm.Program, error)

func Run

func Run(program *vm.Program, env any) (any, error)

Run evaluates given bytecode program.

Types

type Option

type Option func(c *conf.Config)

Option for configuring config.

func AllowUndefinedVariables

func AllowUndefinedVariables() Option

AllowUndefinedVariables allows to use undefined variables inside expressions. This can be used with expr.Env option to partially define a few variables.

func AsAny

func AsAny() Option

AsAny tells the compiler to expect any result.

func AsBool

func AsBool() Option

AsBool tells the compiler to expect a boolean result.

func AsFloat64

func AsFloat64() Option

AsFloat64 tells the compiler to expect a float64 result.

func AsInt

func AsInt() Option

AsInt tells the compiler to expect an int result.

func AsInt64

func AsInt64() Option

AsInt64 tells the compiler to expect an int64 result.

func AsKind

func AsKind(kind reflect.Kind) Option

AsKind tells the compiler to expect kind of the result.

func ConstExpr

func ConstExpr(fn string) Option

ConstExpr defines func expression as constant. If all argument to this function is constants, then it can be replaced by result of this func call on compile step.

func DisableAllBuiltins

func DisableAllBuiltins() Option

DisableAllBuiltins disables all builtins.

func DisableBuiltin

func DisableBuiltin(name string) Option

DisableBuiltin disables builtin function.

func EnableBuiltin

func EnableBuiltin(name string) Option

EnableBuiltin enables builtin function.

func Env

func Env(env any) Option

Env specifies expected input of env for type checks. If struct is passed, all fields will be treated as variables, as well as all fields of embedded structs and struct itself. If map is passed, all items will be treated as variables. Methods defined on this type will be available as functions.

func Function

func Function(name string, fn func(params ...any) (any, error), types ...any) Option

Function adds function to list of functions what will be available in expressions.

func Operator

func Operator(operator string, fn ...string) Option

Operator allows to replace a binary operator with a function.

func Optimize

func Optimize(b bool) Option

Optimize turns optimizations on or off.

func Patch

func Patch(visitor ast.Visitor) Option

Patch adds visitor to list of visitors what will be applied before compiling AST to bytecode.