Go-Stream is a stream processing library to implement the Java Stream API with Go.
non-storage
: Stream is not a data structure, but the view of the data source. The data source can come from slice, map or supplier function.pipeline
: Operate the elements through pipeline, support short-circuit and parallel execution.lazy-evaluation
: The intermediate operation on the stream is lazy, and it will be truly executed only when the terminal operation is performed.
Go-Stream supports the following operations
Stream Operation | ||
---|---|---|
Intermediate operations | Stateless | Filter、Map、Peek、FlatMap |
Stateful | Distinct、Sorted、Skip、Limit、TakeWhile、DropWhile | |
Terminal operations | non short-circuiting | ForEach、Reduce、ReduceFromIdentity、Count、Max、Min、FindLast、ToSlice、ToMap、GroupingBy |
short-circuiting | AllMatch、AnyMatch、NoneMatch、FindFirst |
- installation go-stream library
go get github.com/chinalhr/go-stream
- import
import "github.com/chinalhr/go-stream"
- Use Stream to process data
type widget struct {
color string
weight int
}
widgets := []widget{
{
color: "yellow",
weight: 4,
},
{
color: "red",
weight: 3,
},
{
color: "yellow",
weight: 2,
},
{
color: "blue",
weight: 1,
},
}
sum := stream.OfSlice(widgets).
Filter(func(e types.T) bool {
return e.(widget).color == "yellow"
}).
Map(func(e types.T) (r types.R) {
return e.(widget).weight
}).
Reduce(func(e1 types.T, e2 types.T) types.T {
return e1.(int) e2.(int)
})