de-cycle conduit_macros from conduit_core.

Signed-off-by: Jason Volk <jason@zemos.net>

Cargo.lock

@@ -717,7 +717,6 @@ dependencies = [
 name = "conduit_macros"
 version = "0.4.5"
 dependencies = [
- "conduit_core",
  "proc-macro2",
  "quote",
  "syn 1.0.109",

src/macros/Cargo.toml

@@ -18,7 +18,6 @@ proc-macro = true
 syn.workspace = true
 quote.workspace = true
 proc-macro2.workspace = true
-conduit-core.workspace = true
 
 [lints]
 workspace = true

src/macros/admin.rs

-use conduit_core::utils::string::camel_to_snake_string;
 use proc_macro::{Span, TokenStream};
 use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
 use syn::{parse_macro_input, AttributeArgs, Fields, Ident, ItemEnum, Variant};
 
+use crate::utils::camel_to_snake_string;
+
 pub(super) fn command_dispatch(args: TokenStream, input_: TokenStream) -> TokenStream {
 	let input = input_.clone();
 	let item = parse_macro_input!(input as ItemEnum);

src/macros/mod.rs

 mod admin;
+mod utils;
 
 use proc_macro::TokenStream;
 

src/macros/utils.rs

+#[must_use]
+pub(crate) fn camel_to_snake_string(s: &str) -> String {
+	let mut output = String::with_capacity(
+		s.chars()
+			.fold(s.len(), |a, ch| a.saturating_add(usize::from(ch.is_ascii_uppercase()))),
+	);
+
+	let mut state = false;
+	s.chars().for_each(|ch| {
+		let m = ch.is_ascii_uppercase();
+		let s = exchange(&mut state, !m);
+		if m && s {
+			output.push('_');
+		}
+		output.push(ch.to_ascii_lowercase());
+	});
+
+	output
+}
+
+pub(crate) fn exchange<T: Clone>(state: &mut T, source: T) -> T {
+	let ret = state.clone();
+	*state = source;
+	ret
+}