Encoding

use encoding.qweruse base64_encode, base64_decode from encoding      // Quillo 0.6: only these

base64 = "0.22"hex = "0.4"percent-encoding = "2"

// Base64, hex and query strings, read back.////   quillo run encoding.qwe      then open http://localhost:8080/decode?b64=Y2Fmw6kuse "encoding.qwer"route GET /decode ? { b64: str } = { text: base64_decode(b64)?, again: base64_encode(base64_decode(b64)?) }route GET /hex ? { text: str } = { hex: hex_encode(text), back: hex_decode(hex_encode(text))? }route GET /form = form_decode("name=Ada+Lovelace&city=London%2C%20UK")?

//! Base64, base64url, hex and percent-encoding, both ways: Quillo makes them, this reads them back.//! version: 1.0.0//!//! [dependencies]//! base64 = "0.22"//! hex = "0.4"//! percent-encoding = "2"use base64::engine::general_purpose::{STANDARD, STANDARD_NO_PAD, URL_SAFE_NO_PAD};use base64::Engine;use std::collections::HashMap;fn utf8(bytes: Vec<u8>) -> Result<String, String> {    String::from_utf8(bytes).map_err(|_| "the bytes are not UTF-8 text: use base64_to_file for binary data".to_string())}/// `text` as base64, with padding.pub fn base64_encode(text: &str) -> String {    STANDARD.encode(text)}/// Base64 back to text; padding is optional, and spaces and line breaks are ignored.pub fn base64_decode(b64: &str) -> Result<String, String> {    let clean: String = b64.chars().filter(|c| !c.is_whitespace()).collect();    utf8(STANDARD_NO_PAD.decode(clean.trim_end_matches('=')).map_err(|e| e.to_string())?)}/// `text` as base64url without padding, as JWTs and URLs carry it.pub fn base64url_encode(text: &str) -> String {    URL_SAFE_NO_PAD.encode(text)}/// Base64url back to text, with or without padding.pub fn base64url_decode(b64: &str) -> Result<String, String> {    utf8(URL_SAFE_NO_PAD.decode(b64.trim().trim_end_matches('=')).map_err(|e| e.to_string())?)}/// A file's bytes as base64: an image for a `data:` URL, an attachment for an API.pub fn file_to_base64(path: &str) -> Result<String, String> {    Ok(STANDARD.encode(std::fs::read(path).map_err(|e| format!("{}: {}", path, e))?))}/// Base64 written to a file as the bytes it holds; how many bytes were written.pub fn base64_to_file(b64: &str, path: &str) -> Result<i64, String> {    let clean: String = b64.chars().filter(|c| !c.is_whitespace()).collect();    let bytes = STANDARD_NO_PAD.decode(clean.trim_end_matches('=')).map_err(|e| e.to_string())?;    std::fs::write(path, &bytes).map_err(|e| format!("{}: {}", path, e))?;    Ok(bytes.len() as i64)}/// `text` as lower-case hex.pub fn hex_encode(text: &str) -> String {    hex::encode(text)}/// Hex back to text.pub fn hex_decode(h: &str) -> Result<String, String> {    utf8(hex::decode(h.trim()).map_err(|e| e.to_string())?)}/// Percent-encoding undone: `caf%C3%A9` is `café`. A `+` stays a `+`.pub fn url_decode(text: &str) -> Result<String, String> {    percent_encoding::percent_decode_str(text).decode_utf8().map(|s| s.into_owned()).map_err(|e| e.to_string())}/// A query string or form body as a map: `a=1&b=x+y` is `{ a: "1", b: "x y" }`. A key given twice keeps the last.pub fn form_decode(text: &str) -> Result<HashMap<String, String>, String> {    let mut out = HashMap::new();    for pair in text.trim_start_matches('?').split('&').filter(|p| !p.is_empty()) {        let (k, v) = pair.split_once('=').unwrap_or((pair, ""));        out.insert(url_decode(&k.replace('+', " "))?, url_decode(&v.replace('+', " "))?);    }    Ok(out)}