WIP: feedback needed - no_std

Cargo.toml

@@ -11,9 +11,9 @@ repository = "https://github.com/multiformats/rust-multibase"
 keywords = ["ipld", "ipfs", "multihash", "multibase", "cid"]
 
 [dependencies]
-base-x = "0.2"
-data-encoding = "2.2"
-data-encoding-macro = "0.1.8"
+base-x = { git = "https://github.com/whalelephant/base-x-rs", branch = "no_std", default-features = false }
+data-encoding = { version = "2.3", default-features = false, features = ["alloc"] }
+lazy_static = { features = ["spin_no_std"], version = "1.4.0" }
 
 [dev-dependencies]
 criterion = "0.3"
@@ -25,3 +25,7 @@ harness = false
 
 [workspace]
 members = ["cli"]
+
+[features]
+default = ["std"]
+std = []

src/base.rs

@@ -1,6 +1,9 @@
 use crate::error::{Error, Result};
 use crate::impls::*;
 
+#[cfg(not(feature = "std"))]
+use alloc::{string::String, vec::Vec};
+
 macro_rules! build_base_enum {
     ( $(#[$attr:meta] $code:expr => $base:ident,)* ) => {
         /// List of types currently supported in the multibase spec.

src/encoding.rs

@@ -1,15 +1,58 @@
-use data_encoding::Encoding;
-use data_encoding_macro::{internal_new_encoding, new_encoding};
-
-// Base2 (alphabet: 01)
-pub const BASE2: Encoding = new_encoding! {
-    symbols: "01",
-};
-
-// Base8 (alphabet: 01234567)
-pub const BASE8: Encoding = new_encoding! {
-    symbols: "01234567",
-};
+use data_encoding::{Encoding, Specification};
+use lazy_static::lazy_static;
+
+lazy_static! {
+    // Base2 (alphabet: 01)
+    pub static ref BASE2: Encoding = {
+        let mut spec = Specification::new();
+        spec.symbols.push_str("01");
+        spec.encoding().unwrap()
+    };
+
+    // Base8 (alphabet: 01234567)
+    pub static ref BASE8: Encoding = {
+        let mut spec = Specification::new();
+        spec.symbols.push_str("01234567");
+        spec.encoding().unwrap()
+    };
+
+    // Base32, rfc4648 no padding (alphabet: abcdefghijklmnopqrstuvwxyz234567).
+    pub static ref BASE32_NOPAD_LOWER: Encoding = {
+        let mut spec = Specification::new();
+        spec.symbols.push_str("abcdefghijklmnopqrstuvwxyz234567");
+        spec.encoding().unwrap()
+    };
+
+    // Base32, rfc4648 with padding (alphabet: abcdefghijklmnopqrstuvwxyz234567).
+    pub static ref BASE32_PAD_LOWER: Encoding = {
+        let mut spec = Specification::new();
+        spec.symbols.push_str("abcdefghijklmnopqrstuvwxyz234567");
+        spec.padding = Some('=');
+        spec.encoding().unwrap()
+    };
+
+    // Base32hex, rfc4648 no padding (alphabet: 0123456789abcdefghijklmnopqrstuv).
+    pub static ref BASE32HEX_NOPAD_LOWER: Encoding = {
+        let mut spec = Specification::new();
+        spec.symbols.push_str("0123456789abcdefghijklmnopqrstuv");
+        spec.encoding().unwrap()
+    };
+
+    // Base32hex, rfc4648 with padding (alphabet: 0123456789abcdefghijklmnopqrstuv).
+    pub static ref BASE32HEX_PAD_LOWER: Encoding = {
+        let mut spec = Specification::new();
+        spec.symbols.push_str("0123456789abcdefghijklmnopqrstuv");
+        spec.padding = Some('=');
+        spec.encoding().unwrap()
+    };
+
+    // z-base-32 (used by Tahoe-LAFS) (alphabet: ybndrfg8ejkmcpqxot1uwisza345h769).
+    pub static ref BASE32Z: Encoding = {
+        let mut spec = Specification::new();
+        spec.symbols.push_str("ybndrfg8ejkmcpqxot1uwisza345h769");
+        spec.encoding().unwrap()
+    };
+}
 
 /// Base10 (alphabet: 0123456789)
 pub const BASE10: &str = "0123456789";
@@ -20,45 +63,18 @@ pub const BASE16_LOWER: Encoding = data_encoding::HEXLOWER;
 // Base16 upper hexadecimal (alphabet: 0123456789ABCDEF).
 pub const BASE16_UPPER: Encoding = data_encoding::HEXUPPER;
 
-// Base32, rfc4648 no padding (alphabet: abcdefghijklmnopqrstuvwxyz234567).
-pub const BASE32_NOPAD_LOWER: Encoding = new_encoding! {
-    symbols: "abcdefghijklmnopqrstuvwxyz234567",
-};
-
 // Base32, rfc4648 no padding (alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ234567).
 pub const BASE32_NOPAD_UPPER: Encoding = data_encoding::BASE32_NOPAD;
 
-// Base32, rfc4648 with padding (alphabet: abcdefghijklmnopqrstuvwxyz234567).
-pub const BASE32_PAD_LOWER: Encoding = new_encoding! {
-    symbols: "abcdefghijklmnopqrstuvwxyz234567",
-    padding: '=',
-};
-
 // Base32, rfc4648 with padding (alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ234567).
 pub const BASE32_PAD_UPPER: Encoding = data_encoding::BASE32;
 
-// Base32hex, rfc4648 no padding (alphabet: 0123456789abcdefghijklmnopqrstuv).
-pub const BASE32HEX_NOPAD_LOWER: Encoding = new_encoding! {
-    symbols: "0123456789abcdefghijklmnopqrstuv",
-};
-
 // Base32hex, rfc4648 no padding (alphabet: 0123456789ABCDEFGHIJKLMNOPQRSTUV).
 pub const BASE32HEX_NOPAD_UPPER: Encoding = data_encoding::BASE32HEX_NOPAD;
 
-// Base32hex, rfc4648 with padding (alphabet: 0123456789abcdefghijklmnopqrstuv).
-pub const BASE32HEX_PAD_LOWER: Encoding = new_encoding! {
-    symbols: "0123456789abcdefghijklmnopqrstuv",
-    padding: '=',
-};
-
 /// Base32hex, rfc4648 with padding (alphabet: 0123456789ABCDEFGHIJKLMNOPQRSTUV).
 pub const BASE32HEX_PAD_UPPER: Encoding = data_encoding::BASE32HEX;
 
-// z-base-32 (used by Tahoe-LAFS) (alphabet: ybndrfg8ejkmcpqxot1uwisza345h769).
-pub const BASE32Z: Encoding = new_encoding! {
-    symbols: "ybndrfg8ejkmcpqxot1uwisza345h769",
-};
-
 // Base58 Flickr's alphabet for creating short urls from photo ids.
 pub const BASE58_FLICKR: &str = "123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
 

src/error.rs

@@ -1,4 +1,7 @@
-use std::{error, fmt};
+#[cfg(not(feature = "std"))]
+use core as std;
+
+use std::fmt;
 
 /// Type alias to use this library's [`Error`] type in a `Result`.
 pub type Result<T> = std::result::Result<T, Error>;
@@ -21,7 +24,8 @@ impl fmt::Display for Error {
     }
 }
 
-impl error::Error for Error {}
+#[cfg(feature = "std")]
+impl std::error::Error for Error {}
 
 impl From<base_x::DecodeError> for Error {
     fn from(_: base_x::DecodeError) -> Self {

src/impls.rs

@@ -1,6 +1,9 @@
 use crate::encoding;
 use crate::error::Result;
 
+#[cfg(not(feature = "std"))]
+use alloc::{string::String, vec::Vec};
+
 pub(crate) trait BaseCodec {
     /// Encode with the given byte slice.
     fn encode<I: AsRef<[u8]>>(input: I) -> String;

src/lib.rs

@@ -1,9 +1,12 @@
 //! # multibase
 //!
 //! Implementation of [multibase](https://github.com/multiformats/multibase) in Rust.
-
+#![cfg_attr(not(feature = "std"), no_std)]
 #![deny(missing_docs)]
 
+#[cfg(not(feature = "std"))]
+extern crate alloc;
+
 mod base;
 mod encoding;
 mod error;
@@ -12,6 +15,9 @@ mod impls;
 pub use self::base::Base;
 pub use self::error::{Error, Result};
 
+#[cfg(not(feature = "std"))]
+use alloc::{string::String, vec::Vec};
+
 /// Decode the base string.
 ///
 /// # Examples