dexpr

package module

v0.0.0-...-130fe7b Latest Latest Go to latest Published: Apr 28, 2017 License: MIT Imports: 10 Imported by: 8

Details

Valid go.mod file

The Go module system was introduced in Go 1.11 and is the official dependency management solution for Go.
Redistributable license

Redistributable licenses place minimal restrictions on how software can be used, modified, and redistributed.
Tagged version

Modules with tagged versions give importers more predictable builds.
Stable version

When a project reaches major version v1 it is considered stable.
Learn more about best practices

Repository

github.com/lawrencewoodman/dexpr

README ¶

dexpr

A Go package for evaluating dynamic expressions

Requirements

dlit package

Contributing

If you want to improve this program make a pull request to the repo on github. Please put any pull requests in a separate branch to ease integration and add a test to prove that it works. If you find a bug, please report it at the project's issues tracker also on github.

Licence

Most of the code is licensed under an MIT licence. Please see the file, LICENCE.md, for details.

The parser is based on Go's parser package and licenced under a BSD style licence. Please see the file, GO_LICENSE, for details.

Documentation ¶

Overview ¶

This parser is based on go's parser package, but has been customized to parse expressions suitable for dexpr.

The parser accepts a larger language than is syntactically permitted by the Go spec, for simplicity, and for improved robustness in the presence of syntax errors. For instance, in method declarations, the receiver is treated like an ordinary parameter list and thus may contain multiple entries where the spec permits exactly one. Consequently, the corresponding field in the AST (ast.FuncDecl.Recv) field is not restricted to one entry.

Index ¶

Variables
func Eval(expr string, callFuncs map[string]CallFun, vars map[string]*dlit.Literal) *dlit.Literal
func EvalBool(expr string, callFuncs map[string]CallFun, vars map[string]*dlit.Literal) (bool, error)
type CallFun
type Expr
- func MustNew(expr string, callFuncs map[string]CallFun) *Expr
- func New(expr string, callFuncs map[string]CallFun) (*Expr, error)
type FunctionError
- func (e FunctionError) Error() string
type FunctionNotExistError
- func (e FunctionNotExistError) Error() string
type InvalidExprError
- func (e InvalidExprError) Error() string
type InvalidOpError
- func (e InvalidOpError) Error() string
type VarNotExistError
- func (e VarNotExistError) Error() string

Constants ¶

This section is empty.

Variables ¶

View Source

var ErrDivByZero = errors.New("divide by zero")

View Source

var ErrIncompatibleTypes = errors.New("incompatible types")

View Source

var ErrInvalidCompositeType = errors.New("invalid composite type")

View Source

var ErrInvalidIndex = errors.New("index out of range")

View Source

var ErrSyntax = errors.New("syntax error")

View Source

var ErrTypeNotIndexable = errors.New("type does not support indexing")

View Source

var ErrUnderflowOverflow = errors.New("underflow/overflow")

Functions ¶

func Eval ¶

func Eval(
	expr string,
	callFuncs map[string]CallFun,
	vars map[string]*dlit.Literal,
) *dlit.Literal

Eval compiles an expression and evaluates it with the supplied callFuncs and vars. Any errors produced will be encapsulated in the returned Literal.

func EvalBool ¶

func EvalBool(
	expr string,
	callFuncs map[string]CallFun,
	vars map[string]*dlit.Literal,
) (bool, error)

EvalBool compiles an expression and evaluates it with the supplied callFuncs and vars.

Types ¶

type CallFun ¶

type CallFun func([]*dlit.Literal) (*dlit.Literal, error)

type Expr ¶

type Expr struct {
	Expr string
	Node enode
}

func MustNew ¶

func MustNew(expr string, callFuncs map[string]CallFun) *Expr

func New ¶

func New(expr string, callFuncs map[string]CallFun) (*Expr, error)

func (*Expr) Eval ¶

func (expr *Expr) Eval(vars map[string]*dlit.Literal) *dlit.Literal

func (*Expr) EvalBool ¶

func (expr *Expr) EvalBool(vars map[string]*dlit.Literal) (bool, error)

func (*Expr) String ¶

func (expr *Expr) String() string

type FunctionError ¶

type FunctionError struct {
	FnName string
	Err    error
}

func (FunctionError) Error ¶

func (e FunctionError) Error() string

type FunctionNotExistError ¶

type FunctionNotExistError string

func (FunctionNotExistError) Error ¶

func (e FunctionNotExistError) Error() string

type InvalidExprError ¶

type InvalidExprError struct {
	Expr string
	Err  error
}

func (InvalidExprError) Error ¶

func (e InvalidExprError) Error() string

type InvalidOpError ¶

type InvalidOpError token.Token

func (InvalidOpError) Error ¶

func (e InvalidOpError) Error() string

type VarNotExistError ¶

type VarNotExistError string

func (VarNotExistError) Error ¶

func (e VarNotExistError) Error() string

Source Files ¶

View all Source files

?	: This menu
/	: Search site
f or F	: Jump to
y or Y	: Canonical URL