Merge pull request #17 from urbit/i/15/tas-macro

Add tas!() procedural macro

rust/ares/Cargo.lock

@@ -12,6 +12,7 @@ checksum = "4b46cbb362ab8752921c97e041f5e366ee6297bd428a31275b9fcf1e380f7299"
 name = "ares"
 version = "0.1.0"
 dependencies = [
+ "ares_macros",
  "bitvec",
  "criterion",
  "either",
@@ -23,6 +24,14 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "ares_macros"
+version = "0.1.0"
+dependencies = [
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "atty"
 version = "0.2.14"

rust/ares/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+ares_macros = { path = "../ares_macros" }
 bitvec = "1.0.0"
 either = "1.6.1"
 libc = "0.2.126"

rust/ares/src/interpreter.rs

@@ -3,6 +3,7 @@ use crate::jets;
 use crate::mem::unifying_equality;
 use crate::mem::NockStack;
 use crate::noun::{Atom, Cell, DirectAtom, IndirectAtom, Noun};
+use ares_macros::tas;
 use bitvec::prelude::{BitSlice, Lsb0};
 use either::Either::*;
 use num_traits::cast::{FromPrimitive, ToPrimitive};
@@ -316,7 +317,7 @@ pub fn interpret(stack: &mut NockStack, mut subject: Noun, formula: Noun) -> Nou
                     // match %sham hints, which are scaffolding until we have a real jet dashboard
                     if hint_cell
                         .head()
-                        .raw_equals(DirectAtom::new_unchecked(0x6d616873).as_noun())
+                        .raw_equals(DirectAtom::new_unchecked(tas!(b"sham")).as_noun())
                     {
                         if let Ok(jet_formula) = hint_cell.tail().as_cell() {
                             let jet_name = jet_formula.tail();

rust/ares/src/jets.rs

@@ -1,12 +1,13 @@
 use crate::interpreter::raw_slot;
 use crate::mem::NockStack;
 use crate::noun::{DirectAtom, IndirectAtom, Noun};
+use ares_macros::tas;
 use either::Either::*;
 
 pub fn get_jet(jet_name: Noun) -> Result<fn(&mut NockStack, Noun) -> Noun, ()> {
     match jet_name.as_direct()?.data() {
-        0x636564 => Ok(jet_dec),
-        0x747563 => Ok(jet_cut),
+        tas!(b"dec") => Ok(jet_dec),
+        tas!(b"cut") => Ok(jet_cut),
         _ => Err(()),
     }
 }

rust/ares/src/lib.rs

@@ -6,3 +6,15 @@ pub mod mem;
 pub mod mug;
 pub mod noun;
 pub mod serialization;
+
+#[cfg(test)]
+mod tests {
+
+    #[test]
+    fn tas() {
+        use ares_macros::tas;
+        assert_eq!(tas!(b"cut"), 0x747563);
+        assert_eq!(tas!(b"dec"), 0x636564);
+        assert_eq!(tas!(b"prop"), 0x706f7270);
+    }
+}

rust/ares_macros/Cargo.lock

@@ -0,0 +1,46 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "ares_macros"
+version = "0.1.0"
+dependencies = [
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.50"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ef7d57beacfaf2d8aee5937dab7b7f28de3cb8b1828479bb5de2a7106f2bae2"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8856d8364d252a14d474036ea1358d63c9e6965c8e5c1885c18f73d70bff9c7b"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.107"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1f4064b5b16e03ae50984a5a8ed5d4f8803e6bc1fd170a3cda91a1be4b18e3f5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "84a22b9f218b40614adcb3f4ff08b703773ad44fa9423e4e0d346d5db86e4ebc"

rust/ares_macros/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "ares_macros"
+version = "0.1.0"
+edition = "2021"
+
+
+[lib]
+proc-macro = true
+
+[dependencies]
+quote = "1.0"
+syn = "1.0"

rust/ares_macros/src/lib.rs

@@ -0,0 +1,22 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use std::mem::size_of;
+use syn::{self, LitByteStr};
+
+#[proc_macro]
+pub fn tas(input: TokenStream) -> TokenStream {
+    let byte_str: LitByteStr = syn::parse(input).expect("failed to parse input");
+    let bytes = byte_str.value();
+    if bytes.len() > size_of::<u64>() {
+        panic!(
+            "\"{}\" does not fit in a u64: must be 8 or fewer characters, not {}",
+            byte_str.token(),
+            bytes.len()
+        );
+    }
+    let mut val: u64 = 0;
+    for byte in bytes.into_iter().rev() {
+        val = (val << u8::BITS) | u64::from(byte);
+    }
+    quote!(#val).into()
+}