fix: re-export slice! macro (#2008)

leptos/src/lib.rs

@@ -180,7 +180,7 @@ pub mod error {
 pub use leptos_macro::template;
 #[cfg(not(all(target_arch = "wasm32", feature = "template_macro")))]
 pub use leptos_macro::view as template;
-pub use leptos_macro::{component, island, server, slot, view, Params};
+pub use leptos_macro::{component, island, server, slice, slot, view, Params};
 pub use leptos_reactive::*;
 pub use leptos_server::{
     self, create_action, create_multi_action, create_server_action,

leptos_macro/src/lib.rs

@@ -971,9 +971,9 @@ pub(crate) fn attribute_value(attr: &KeyedAttribute) -> &syn::Expr {
     }
 }
 
-/// Generates a `lens` into struct with a default getter and setter
+/// Generates a `slice` into a struct with a default getter and setter.
 ///
-/// Can be used to access deeply nested fields within a global state object
+/// Can be used to access deeply nested fields within a global state object.
 ///
 /// ```rust
 /// # use leptos::{create_runtime, create_rw_signal};

leptos_macro/src/slice.rs

@@ -1,59 +1,55 @@
 extern crate proc_macro;
 
 use proc_macro::TokenStream;
-use proc_macro2::Ident;
-use quote::quote;
+use quote::{quote, ToTokens};
 use syn::{
     parse::{Parse, ParseStream},
     parse_macro_input,
     punctuated::Punctuated,
-    token::Dot,
-    Token, Type,
+    Token,
 };
 
 struct SliceMacroInput {
-    pub root: Ident,
-    pub path: Punctuated<Type, Dot>,
+    root: syn::Ident,
+    path: Punctuated<syn::Ident, Token![.]>,
 }
 
 impl Parse for SliceMacroInput {
-    fn parse(input: ParseStream) -> Result<Self, syn::Error> {
-        let root = syn::Ident::parse(input)?;
-        let _dot = <Token![.]>::parse(input)?;
-        let path = input.parse_terminated(Type::parse, Token![.])?;
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let root: syn::Ident = input.parse()?;
+        input.parse::<Token![.]>()?;
+        // do not accept trailing punctuation
+        let path: Punctuated<syn::Ident, Token![.]> =
+            Punctuated::parse_separated_nonempty(input)?;
 
         if path.is_empty() {
-            return Err(syn::Error::new(input.span(), "Expected identifier"));
+            return Err(input.error("expected identifier"));
         }
 
-        if path.trailing_punct() {
-            return Err(syn::Error::new(
-                input.span(),
-                "Unexpected trailing `.`",
-            ));
+        if !input.is_empty() {
+            return Err(input.error("unexpected token"));
         }
 
-        Ok(SliceMacroInput { root, path })
+        Ok(Self { root, path })
     }
 }
 
-impl From<SliceMacroInput> for TokenStream {
-    fn from(val: SliceMacroInput) -> Self {
-        let root = val.root;
-        let path = val.path;
+impl ToTokens for SliceMacroInput {
+    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
+        let root = &self.root;
+        let path = &self.path;
 
-        quote! {
+        tokens.extend(quote! {
             ::leptos::create_slice(
                 #root,
                 |st: &_| st.#path.clone(),
                 |st: &mut _, n| st.#path = n
             )
-        }
-        .into()
+        })
     }
 }
 
 pub fn slice_impl(tokens: TokenStream) -> TokenStream {
     let input = parse_macro_input!(tokens as SliceMacroInput);
-    input.into()
+    input.into_token_stream().into()
 }

leptos_macro/tests/slice/red.stderr

@@ -14,7 +14,7 @@ error: expected `.`
    |
    = note: this error originates in the macro `slice` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: Expected identifier
+error: unexpected end of input, expected identifier
   --> tests/slice/red.rs:25:18
    |
 25 |     let (_, _) = slice!(outer_signal.);
@@ -22,7 +22,7 @@ error: Expected identifier
    |
    = note: this error originates in the macro `slice` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: Unexpected trailing `.`
+error: unexpected end of input, expected identifier
   --> tests/slice/red.rs:27:18
    |
 27 |     let (_, _) = slice!(outer_signal.inner.);