predicate

Documentation

Overview

Package predicate provides functions that wrap existing actions but executes them only on conditions ("predicates"). If a predicate evaluates to false, the wrapped action is not called and skips the step in the pipeline, indicating success.

Index

• func ToNestedStep(name string, p *pipeline.Pipeline, predicate Predicate) pipeline.Step
• func ToStep(name string, action pipeline.ActionFunc, predicate Predicate) pipeline.Step
• func WrapIn(originalStep pipeline.Step, predicate Predicate) pipeline.Step
• type Predicate
  • func And(p1, p2 Predicate) Predicate
  • func Bool(v bool) Predicate
  • func Not(predicate Predicate) Predicate
  • func Or(p1, p2 Predicate) Predicate

Functions

func ToNestedStep

func ToNestedStep(name string, p *pipeline.Pipeline, predicate Predicate) pipeline.Step

ToNestedStep wraps the given pipeline in its own step. When the step's function is called, the given Predicate will evaluate whether the nested pipeline.Pipeline should actually run. It returns the pipeline's pipeline.Result, otherwise an empty (successful) pipeline.Result struct.

func ToStep

func ToStep(name string, action pipeline.ActionFunc, predicate Predicate) pipeline.Step

ToStep wraps the given action func in its own step. When the step's function is called, the given Predicate will evaluate whether the action should actually run. It returns the action's pipeline.Result, otherwise an empty (successful) pipeline.Result struct.

func WrapIn

func WrapIn(originalStep pipeline.Step, predicate Predicate) pipeline.Step

WrapIn returns a new step that wraps the given step and executes its action only if the given Predicate evaluates true.

Types

type Predicate

type Predicate func(step pipeline.Step) bool

Predicate is a function that expects 'true' if a pipeline.ActionFunc should run. Is is evaluated lazily resp. only when needed.

func And

func And(p1, p2 Predicate) Predicate

And returns a Predicate that does logical AND of the given predicates. p2 is not evaluated if p1 evaluates already to false.

func Bool

func Bool(v bool) Predicate

Bool returns a Predicate that simply returns v when evaluated.

func Not

func Not(predicate Predicate) Predicate

Not returns a Predicate that evaluates, but then negates the given Predicate.

func Or

func Or(p1, p2 Predicate) Predicate

Or returns a Predicate that does logical OR of the given predicates. p2 is not evaluated if p1 evaluates already to true.