Documentation
¶
Overview ¶
TICKscript is a simple invocation chaining DSL.
See the examples for how its used and example syntax of the DSL.
Index ¶
- Variables
- func Evaluate(script string, scope *stateful.Scope, predefinedVars map[string]Var, ...) (_ map[string]Var, err error)
- func Format(script string) (string, error)
- type PartialDescriber
- type ReflectionDescriber
- func (r *ReflectionDescriber) CallChainMethod(name string, args ...interface{}) (interface{}, error)
- func (r *ReflectionDescriber) Desc() string
- func (r *ReflectionDescriber) HasChainMethod(name string) bool
- func (r *ReflectionDescriber) HasProperty(name string) bool
- func (r *ReflectionDescriber) Property(name string) interface{}
- func (r *ReflectionDescriber) SetProperty(name string, values ...interface{}) (interface{}, error)
- type SelfDescriber
- type Var
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ErrEmptyStack = errors.New("stack is empty")
Functions ¶
func Evaluate ¶
func Evaluate(script string, scope *stateful.Scope, predefinedVars map[string]Var, ignoreMissingVars bool) (_ map[string]Var, err error)
Parse and evaluate a given script for the scope. Returns a set of default vars. If a set of predefined vars is provided, they may effect the default var values.
Example ¶
package main
import (
"fmt"
"github.com/influxdata/kapacitor/tick/stateful"
)
type Process struct {
Name string
Children []*Process
}
func (p *Process) Spawn() *Process {
child := &Process{}
p.Children = append(p.Children, child)
return child
}
func (p *Process) String() string {
return fmt.Sprintf("{%q %s}", p.Name, p.Children)
}
func main() {
//Run a test that evaluates the DSL against the Process struct.
script := `
//Name the parent
parent.name('parent')
// Spawn a first child
var child1 = parent|spawn()
// Name the first child
child1.name('child1')
//Spawn a grandchild and name it
child1|spawn().name('grandchild')
//Spawn a second child and name it
parent|spawn().name('child2')
`
scope := stateful.NewScope()
parent := &Process{}
scope.Set("parent", parent)
_, err := Evaluate(script, scope, nil, false)
if err != nil {
fmt.Println(err)
}
fmt.Println(parent)
}
Output: {"parent" [{"child1" [{"grandchild" []}]} {"child2" []}]}
Types ¶
type PartialDescriber ¶
PartialDescriber can provide a description of its chain methods that hide embedded property methods.
type ReflectionDescriber ¶
type ReflectionDescriber struct {
// contains filtered or unexported fields
}
Wraps any object as a SelfDescriber using reflection.
Uses tags on fields to determine if a method is really a PropertyMethod Can disambiguate property fields and chain methods of the same name but from different composed anonymous fields. Cannot disambiguate property methods and chain methods of the same name. See NewReflectionDescriber for providing explicit chain methods in this case.
Example:
type MyType struct {
UseX `tick:"X"`
}
func (m *MyType) X() *MyType{
m.UseX = true
return m
}
UseX will be ignored as a property and the method X will become a property method.
Expects that all callable methods are pointer receiver methods.
func NewReflectionDescriber ¶
func NewReflectionDescriber(obj interface{}, chainMethods map[string]reflect.Value) (*ReflectionDescriber, error)
Create a NewReflectionDescriber from an object. The object must be a pointer type. Use the chainMethods parameter to provide a set of explicit methods that should be considered chain methods even if an embedded type declares them as property methods
Example:
type MyType struct {
UseX `tick:"X"`
}
func (m *MyType) X() *MyType{
m.UseX = true
return m
}
type AnotherType struct {
MyType
}
func (a *AnotherType) X() *YetAnotherType {
// do chain method work here...
}
// Now create NewReflectionDescriber with X as a chain method and property method
at := new(AnotherType)
rd := NewReflectionDescriber(at, map[string]reflect.Value{
"X": reflect.ValueOf(at.X),
})
rd.HasProperty("x") // true
rd.HasChainMethod("x") // true
func (*ReflectionDescriber) CallChainMethod ¶
func (r *ReflectionDescriber) CallChainMethod(name string, args ...interface{}) (interface{}, error)
func (*ReflectionDescriber) Desc ¶
func (r *ReflectionDescriber) Desc() string
func (*ReflectionDescriber) HasChainMethod ¶
func (r *ReflectionDescriber) HasChainMethod(name string) bool
Using reflection check if the object has the method or field. A field is a valid method because we can set it via reflection too.
func (*ReflectionDescriber) HasProperty ¶
func (r *ReflectionDescriber) HasProperty(name string) bool
Using reflection check if the object has a field with the property name.
func (*ReflectionDescriber) Property ¶
func (r *ReflectionDescriber) Property(name string) interface{}
func (*ReflectionDescriber) SetProperty ¶
func (r *ReflectionDescriber) SetProperty(name string, values ...interface{}) (interface{}, error)
type SelfDescriber ¶
type SelfDescriber interface {
//A description the object
Desc() string
HasChainMethod(name string) bool
CallChainMethod(name string, args ...interface{}) (interface{}, error)
HasProperty(name string) bool
Property(name string) interface{}
SetProperty(name string, args ...interface{}) (interface{}, error)
}
Interface for interacting with objects. If an object does not self describe via this interface than a reflection based implemenation will be used.
Source Files
Directories