lambda/readme.md

# lambda

package lambda provides tools for performing operations on generic array types

features:


features:
 - Map [T] -> [T]
 - MapV [T] -> [V]
 - MapError [T] -> ([T], [error]
 - MapErrorV [T] -> ([V], [error]
 - Foldr [T] -> T
 - Foldl [T] -> T
 - Entries map[K]V -> ([K], [V])
 - Flatten [[T]] -> [T]
 - Merge ([T], [T]) -> [T]
 - Split ([T], int) -> [[T]]

todo:
 - idk

example: adding some numbers

```
package main
import (
  "log"

  "git.tuxpa.in/a/lambda"
)
func main(){
	arr := []int{1, 2, 3, 4, 6, 5}
	ans := lambda.Map(arr, func(x int) int { return x + 4 })
	// ans = []int{5, 6, 7, 8, 10, 9}
  log.Println(ans)
}
```


## parallel

subpackage parallel provides parallelized operations on generic array types

features:
 - Map [T] -> [T]
 - MapV [T] -> [V]
 - MapError [T] -> ([T], [error]
 - MapErrorV [T] -> ([V], [error]

todo:
 - idk

example usage:

making a request

```
package main

import (
    "encoding/json"
    "fmt"
    "log"
    "net/http"

    "git.tuxpa.in/a/lambda/parallel"
)

type someResult struct {
    Title string `json:"title"`
    Id    int    `json:"id"`
}

func main() {
    var requests = make([]*http.Request, 20)

    for i := range requests {
        r, _ := http.NewRequest("GET", fmt.Sprintf("https://jsonplaceholder.typicode.com/todos/%d", i), nil)
        requests[i] = r
    }

    results, errs := parallel.MapErrorV(requests, func(r *http.Request) (*someResult, error) {
        out := &someResult{}
        res, err := http.DefaultClient.Do(r)
        if err != nil {
            return nil, err
        }
        defer res.Body.Close()
        err = json.NewDecoder(res.Body).Decode(out)
        return out, err
    }, 4)

    for i, v := range results {
        if errs[i] != nil {
            log.Printf("err: %s", errs[i])
        } else {
            log.Printf("result: %+v", v)
        }
    }
}
```