rulengine

README

Rulengine

Rulegine provides support for evaluating arbitrary expressions.

Installation

When used with Go modules, use the following import path:

go get github.com/leonests/rulengine

Quickstart

Bracket Accessor

Dot Accessor

Documentation

Index

• type Expr
  • func NewExpr(expr string) (res *Expr, err error)
  • func (expr *Expr) Eval(params map[string]interface{}) (interface{}, error)
• type LexerToken
• type TokenType
  • func (op TokenType) Priority() opPriority
  • func (t TokenType) String() string

Types

type Expr

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

func NewExpr

func NewExpr(expr string) (res *Expr, err error)

func (*Expr) Eval

func (expr *Expr) Eval(params map[string]interface{}) (interface{}, error)

type LexerToken

type LexerToken struct {
	Type  TokenType
	Value interface{}
}

type TokenType

type TokenType int //enum

const (
	ILLEGAL TokenType = iota

	// literal operators
	CHAR     // 'a', '爱', ...
	STRING   // "abc"
	NUMBER   // 123, 123.456 treated as float64
	BOOL     // true, false
	VARIABLE // a1, b_2, c
	SELECTOR // a.b.c,
	ACCESSOR // .a.b

	// prefix operators
	NOT // !
	NEG // -

	// normal operators
	ADD // +
	SUB // -
	MUL // *
	QUO // /
	REM // %

	AND // &
	OR  // |
	XOR // ^
	SHL // <<
	SHR // >>

	// ternary operators
	TERNARY_IF
	TERNARY_ELSE

	// logical operators
	LAND // &&
	LOR  // ||

	// comparer operators
	EQ  // ==
	NEQ // !=
	LT  // <
	GT  // >
	LEQ // <=
	GEQ // >=

	// clause operators
	LPAREN // (
	RPAREN // )

	LBRACKET // [
	RBRACKET // ]

	LITERAL // represent all literal operators
	CLAUSE  // represent all clause operator
	EOF
)

func (TokenType) Priority

func (op TokenType) Priority() opPriority

func (TokenType) String

func (t TokenType) String() string