λ
λ is a functional programming framework for go, which adds support for an alternative error handling workflow using options.
Example usage
Read all lines from stdin
package main
import (
"fmt"
λ "github.com/4thel00z/lambda/v1"
"os"
)
func main() {
content := λ.Slurp(os.Stdin).UnwrapString()
// do things with content...
}
Read a file and pipe it to stdout
package main
import (
λ "github.com/4thel00z/lambda/v1"
"os"
)
func main() {
λ.Open("lorem_ipsum.txt").Slurp().WriteString(os.Stdout)
}
Read a JSON file into a struct
package main
import (
λ "github.com/4thel00z/lambda/v1"
"strings"
)
type MagicSpell struct {
Name string `json:"name"`
AttackPower float64 `json:"attack_power"`
Type string `json:"type"`
Description string `json:"description"`
}
func main() {
var (
m MagicSpell
)
λ.Open("magic.json").Slurp().JSON(&m).Catch(λ.Die)
}
Functional conditionals
You never need to check an error with an if clause again. Instead you can define the flow as functional chain,
start point is always λ.If
.
You even can reuse the same chain, it doesn't contain data. You pass the data via Conditional.Do
.
package main
import (
λ "github.com/4thel00z/lambda/v1"
)
func main() {
manipulateError := λ.Return(λ.Wrap(nil, λ.Error("this error will be thrown")))
input := λ.Wrap(nil, λ.Error("something is weird"))
output := λ.If(λ.HasError, manipulateError).Else(λ.Cry).Do(input)
λ.If(λ.HasNoError, λ.Identity).Else(λ.Cry).Do(output)
}
Make Rest calls
package main
import (
λ "github.com/4thel00z/lambda/v1"
"os"
)
func main() {
λ.Get("https://ransomware.host").Do().Slurp().WriteString(os.Stdout)
}
Simple AES-CBC encryption with PKC7 Padding
package main
import (
"crypto/rand"
λ "github.com/4thel00z/lambda/v1"
"io"
"strings"
)
var (
loremIpsum = `Lorem ipsum dolor sit amet, consetetur sadipscing elitr,
sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat,
sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum.
Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat,
sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren,
no sea takimata sanctus est Lorem ipsum dolor sit amet.`
loremIpsumReader = strings.NewReader(loremIpsum)
)
func getRandomKey() []byte {
key := make([]byte, 32)
_, err := rand.Read(key)
if err != nil {
panic(err)
}
return key
}
func main() {
key := getRandomKey()
if λ.Read(loremIpsumReader).Encrypt(key).Decrypt(key).UnwrapString() != loremIpsum {
panic("encryption and decryption doesn't work")
}
// test for random payload and key that enc & decryption works fine
for i := 0; i < 10; i++ {
key = getRandomKey()
o := λ.Read(io.LimitReader(rand.Reader, 1024))
text := o.UnwrapString()
if o.Encrypt(key).Decrypt(key).UnwrapString() != text {
panic("encryption and decryption doesn't work")
}
}
}
Todo
- Make Option more flexible an pretty
License
This project is licensed under the GPL-3 license.