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 (
	"os"

	λ "github.com/4thel00z/lambda/v1"
)

func main() {
	λ.Get("https://ransomware.host").Do().Slurp().WriteToWriter(os.Stdout)
}

Simple AES-CBC encryption with PKCS7 padding

package main

import (
	"crypto/rand"
	"io"
	"strings"

	λ "github.com/4thel00z/lambda/v1"
)

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).EncryptAES(key).DecryptAES(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.EncryptAES(key).DecryptAES(key).UnwrapString() != text {
			panic("encryption and decryption doesn't work")
		}
	}
}

Pubkey cryptography

package main

import (
	"log"

	λ "github.com/4thel00z/lambda/v1"
)

func main() {
	rsa := λ.RSA(4096)
	println(rsa.ToPublicKeyPemString())
	println(rsa.ToPrivateKeyPemString())
	original := "Some important message which needs to stay secret lel"
	secretMsg := rsa.EncryptRSA(original).UnwrapString()
	if original == secretMsg {
		log.Fatalln("This encryption don't work boi!")
	}
	if original != rsa.DecryptRSA(secretMsg).UnwrapString() {
		log.Fatalln("This decryption don't work boi!")
	}

	// Use rsa.UnwrapPrivateKey() and rsa.UnwrapPublicKey() if you want to extract the raw key material
	// You can load it via λ.LoadRSA(pub,priv)
}

How to generate a sha256 checksum

package main

import (
	"bytes"

	λ "github.com/4thel00z/lambda/v1"
)

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 = bytes.NewReader([]byte(loremIpsum))
)

func main() {
	expected := "70026299e7c4b3bf5b6256b2069ae0cbc2e0960cad1acb51208a311f3864d5bd"
	if λ.Read(loremIpsumReader).Checksum().UnwrapChecksum() != expected {
		panic("sha256 of loremIpsum is wrong!")
	}
}

How to render markdown and print it to stdout

package main

import (
	"fmt"

	λ "github.com/4thel00z/lambda/v1"
)

func main() {
	out := λ.Markdown().Render(`# Markdown
This is so awesome

## Why is this section so nice
Really dunno`).UnwrapString()

	fmt.Print(out)
}