diff options
Diffstat (limited to 'mingling_macros')
| -rw-r--r-- | mingling_macros/src/attr/completion.rs | 232 | ||||
| -rw-r--r-- | mingling_macros/src/lib.rs | 40 |
2 files changed, 121 insertions, 151 deletions
diff --git a/mingling_macros/src/attr/completion.rs b/mingling_macros/src/attr/completion.rs index cbc0fef..71acaae 100644 --- a/mingling_macros/src/attr/completion.rs +++ b/mingling_macros/src/attr/completion.rs @@ -34,52 +34,92 @@ pub(crate) fn completion_attr(attr: TokenStream, item: TokenStream) -> TokenStre let inputs = &sig.inputs; let output = &sig.output; - // The first parameter (if any) is the completion context. It may be - // `&ShellContext`, an owned `ShellContext`, or any other type that - // implements `From<&ShellContext>`. With no parameters, the completion - // function simply ignores the shell context. - let ctx_ty: Option<Type> = match inputs.first() { - None => None, - Some(FnArg::Typed(PatType { ty, .. })) => Some((**ty).clone()), - Some(FnArg::Receiver(_)) => { - return syn::Error::new( - inputs.span(), - "Completion function cannot have self parameter", - ) - .to_compile_error() - .into(); - } - }; + // Parameter classification: + // - Owned (non-reference) parameters are **Shell sources**: each is derived + // from `&ShellContext` via `From<&ShellContext>` (identity `From` covers + // `ShellContext` itself). + // - `&T` / `&mut T` parameters are resource injections (unchanged). + // - `&ShellContext` is rejected with a helpful message: use the owned + // `ShellContext` (or any other `From<&ShellContext>` type) instead. + let mut derived_stmts: Vec<proc_macro2::TokenStream> = Vec::new(); + let mut call_args: Vec<proc_macro2::TokenStream> = Vec::new(); + let mut resources = Vec::new(); - // Resource injection starts after the context parameter. - let resource_skip = usize::from(ctx_ty.is_some()); - let resources = match extract_resources_from_args(sig, resource_skip) { - Ok(r) => r, - Err(e) => return e.to_compile_error().into(), - }; - if ctx_ty.is_none() && !resources.is_empty() { - return syn::Error::new( - inputs.span(), - "A completion function without a context parameter cannot inject resources", - ) - .to_compile_error() - .into(); - } + for (idx, arg) in inputs.iter().enumerate() { + match arg { + FnArg::Typed(PatType { pat, ty, .. }) => { + if let Type::Reference(ref_type) = &**ty { + // `&ShellContext` is no longer allowed: it clashes with the + // resource-injection semantics of references. + if is_shell_context_path(&ref_type.elem) { + return syn::Error::new( + ty.span(), + "`&ShellContext` is not supported; use the owned `ShellContext` \ + (or any other type implementing `From<&ShellContext>`) as a value \ + parameter", + ) + .to_compile_error() + .into(); + } - // Bind the shell context to the declared parameter type (identity `From` - // covers `&ShellContext` itself). - let (ctx_bind_stmt, ctx_call_arg) = ctx_ty.as_ref().map_or_else( - || (quote! { let _ = ctx; }, quote! {}), - |ty| { - ( - quote! { - let __ctx: #ty = - <#ty as ::std::convert::From<&::mingling::ShellContext>>::from(ctx); - }, - quote! { __ctx }, - ) - }, - ); + // Reference: resource injection (requires a named binding). + let var_name = match &**pat { + Pat::Ident(pat_ident) => pat_ident.ident.clone(), + _ => { + return syn::Error::new( + pat.span(), + "Resource injection parameter must be a simple identifier", + ) + .to_compile_error() + .into(); + } + }; + + // Reference: resource injection. + let (inner_type, is_mut) = match &*ref_type.elem { + Type::Path(type_path) => { + let is_mut = ref_type.mutability.is_some(); + (type_path.clone(), is_mut) + } + _ => { + return syn::Error::new( + ty.span(), + "Reference resource type must be a type path", + ) + .to_compile_error() + .into(); + } + }; + resources.push(ResourceInjection { + var_name: var_name.clone(), + full_type: (**ty).clone(), + inner_type, + is_ref: true, + is_mut, + }); + call_args.push(quote! { #var_name }); + } else { + // Owned value: derive from `&ShellContext`. The parameter + // name is irrelevant (anonymous `_` is fine) since the + // derived binding is generated by this macro. + let derived_ident = Ident::new(&format!("__ctx_derived_{idx}"), pat.span()); + derived_stmts.push(quote! { + let #derived_ident: #ty = + <#ty as ::std::convert::From<&::mingling::ShellContext>>::from(ctx); + }); + call_args.push(quote! { #derived_ident }); + } + } + FnArg::Receiver(_) => { + return syn::Error::new( + arg.span(), + "Completion function cannot have self parameter", + ) + .to_compile_error() + .into(); + } + } + } let fn_body = &input_fn.block; @@ -96,26 +136,11 @@ pub(crate) fn completion_attr(attr: TokenStream, item: TokenStream) -> TokenStre let struct_name = Ident::new(&internal_name, fn_name.span()); let program_type = crate::default_program_path(); - let has_resources = !resources.is_empty(); let mut_resources: Vec<_> = resources.iter().filter(|r| r.is_mut).collect(); let immut_resource_stmts = generate_immut_resource_bindings(resources.iter(), &program_type); - let resource_args: Vec<_> = resources - .iter() - .map(|res| { - let var_name = &res.var_name; - quote! { #var_name } - }) - .collect(); - - let fn_call = if has_resources { - quote! { #fn_name(#ctx_call_arg, #(#resource_args),*) } - } else if ctx_ty.is_some() { - quote! { #fn_name(#ctx_call_arg) } - } else { - quote! { #fn_name() } - }; + let fn_call = quote! { #fn_name(#(#call_args),*) }; let inner_call = if mut_resources.is_empty() { fn_call @@ -133,13 +158,10 @@ pub(crate) fn completion_attr(attr: TokenStream, item: TokenStream) -> TokenStre wrapped }; - let comp_body = if has_resources { - quote! { - #(#immut_resource_stmts)* - #inner_call - } - } else { - quote! { #inner_call } + let comp_body = quote! { + #(#derived_stmts)* + #(#immut_resource_stmts)* + #inner_call }; // A `()` return (or no return type) means "no suggestions": map it to an @@ -172,7 +194,6 @@ pub(crate) fn completion_attr(attr: TokenStream, item: TokenStream) -> TokenStre type Previous = #previous_type_path; fn comp(ctx: &::mingling::ShellContext) -> ::mingling::Suggest { - #ctx_bind_stmt #return_stmt } } @@ -208,69 +229,16 @@ pub(crate) fn completion_attr(attr: TokenStream, item: TokenStream) -> TokenStre expanded.into() } -/// Extract resource injection parameters from function arguments (skipping the first N params). -fn extract_resources_from_args( - sig: &syn::Signature, - skip: usize, -) -> syn::Result<Vec<ResourceInjection>> { - let mut resources = Vec::new(); - for arg in sig.inputs.iter().skip(skip) { - match arg { - FnArg::Typed(PatType { pat, ty, .. }) => { - let var_name = match &**pat { - Pat::Ident(pat_ident) => pat_ident.ident.clone(), - _ => { - return Err(syn::Error::new( - pat.span(), - "Resource injection parameter must be a simple identifier", - )); - } - }; - - let full_type = *(*ty).clone(); - - let (inner_type, is_ref, is_mut) = match &full_type { - Type::Reference(ref_type) => match &*ref_type.elem { - Type::Path(type_path) => { - let is_mut = ref_type.mutability.is_some(); - (type_path.clone(), true, is_mut) - } - _ => { - return Err(syn::Error::new( - ty.span(), - "Reference resource type must be a type path", - )); - } - }, - Type::Path(_) => { - return Err(syn::Error::new( - ty.span(), - "Resource injection parameter must be a reference (`&T` or `&mut T`)", - )); - } - _ => { - return Err(syn::Error::new( - ty.span(), - "Resource injection type must be a type path or reference", - )); - } - }; - - resources.push(ResourceInjection { - var_name, - full_type, - inner_type, - is_ref, - is_mut, - }); - } - FnArg::Receiver(_) => { - return Err(syn::Error::new( - arg.span(), - "Resource injection parameter cannot be self", - )); - } - } +/// Returns `true` when the type is a path whose last segment is `ShellContext` +/// (e.g. `ShellContext` or `mingling::ShellContext`). +fn is_shell_context_path(ty: &Type) -> bool { + if let Type::Path(type_path) = ty { + type_path + .path + .segments + .last() + .is_some_and(|seg| seg.ident == "ShellContext") + } else { + false } - Ok(resources) } diff --git a/mingling_macros/src/lib.rs b/mingling_macros/src/lib.rs index 2271e21..d00773c 100644 --- a/mingling_macros/src/lib.rs +++ b/mingling_macros/src/lib.rs @@ -689,31 +689,32 @@ pub fn renderer(attr: TokenStream, item: TokenStream) -> TokenStream { /// 2. Registering the completion mapping for the specified entry type. /// 3. Keeping the original function for direct calls. /// -/// # Syntax -/// -/// The completion function accepts a relaxed signature: +/// # Signature rules /// -/// - **Context parameter (optional):** the first parameter may be `&ShellContext`, -/// an owned `ShellContext`, or any type implementing `From<&ShellContext>`. -/// With no parameters at all, the shell context is ignored. -/// - **Return type:** anything implementing `Into<Suggest>`, e.g. `Suggest`, -/// `Vec<String>`, `Vec<(String, String)>` (suggestion + description), or a -/// set of [`SuggestItem`](https://docs.rs/mingling/latest/mingling/struct.SuggestItem.html)s. -/// - **Resource injection:** remaining parameters are injected resources -/// (only when a context parameter is present). +/// - **Owned (non-reference) parameters** are *shell sources*: each one is derived +/// from `&ShellContext` via `From<&ShellContext>`. This covers `ShellContext` +/// itself (via its `Clone`-based `From` impl), framework state types, and any +/// user-defined state derived from the shell context. +/// - **`&T` / `&mut T` parameters** are resource injections (same as `#[chain]`). +/// - **`&ShellContext` is rejected** — use the owned `ShellContext` instead, since +/// reference parameters are reserved for resources. +/// - The return type can be anything implementing `Into<Suggest>`: `Suggest`, +/// `Vec<String>`, `Vec<&str>`, `Vec<(String, String)>` (suggestion + description), +/// a set of [`SuggestItem`](https://docs.rs/mingling/latest/mingling/struct.SuggestItem.html)s, +/// or `()` / no return type for "no suggestions". /// /// ```rust,ignore /// // No context, return simple suggestions /// #[completion(EntryType)] -/// fn complete_static() -> Vec<String> { vec!["a", "b"].into_iter().map(str::to_string).collect() } +/// fn complete_static() -> Vec<&str> { vec!["a", "b"] } /// -/// // Owned context (via `From<&ShellContext>`), suggestions with descriptions +/// // Multiple shell-derived states + resource injection /// #[completion(EntryType)] -/// fn complete_owned(ctx: ShellContext) -> Vec<(String, String)> { /* ... */ } +/// fn complete_mixed(pos: PositionState, flags: FlagState, db: &ResDb) -> Vec<(String, String)> { /* ... */ } /// -/// // Borrowed context (classic form) +/// // Empty function: this command needs no completion /// #[completion(EntryType)] -/// fn complete_borrowed(ctx: &ShellContext) -> Suggest { /* ... */ } +/// fn complete_nothing() {} /// ``` /// /// # Example @@ -723,7 +724,7 @@ pub fn renderer(attr: TokenStream, item: TokenStream) -> TokenStream { /// use mingling::{ShellContext, Suggest}; /// /// #[completion(MyEntry)] -/// fn complete_my_command(ctx: &ShellContext) -> Suggest { +/// fn complete_my_command(ctx: ShellContext) -> Suggest { /// if ctx.previous_word == "--type" { /// return suggest!(); /// } @@ -740,8 +741,9 @@ pub fn renderer(attr: TokenStream, item: TokenStream) -> TokenStream { /// # Requirements /// /// - The `comp` feature must be enabled. -/// - The first parameter (if any) must implement `From<&ShellContext>`. -/// - The return type must implement `Into<Suggest>`. +/// - Owned parameters must implement `From<&ShellContext>`. +/// - Reference parameters are resource injections; `&ShellContext` is not allowed. +/// - The return type must implement `Into<Suggest>` (or be `()`). /// - The function cannot be async. #[cfg(feature = "comp")] #[proc_macro_attribute] |