mirror of
https://github.com/DioxusLabs/dioxus
synced 2024-12-21 01:53:15 +00:00
1184 lines
48 KiB
Rust
1184 lines
48 KiB
Rust
//! This code mostly comes from idanarye/rust-typed-builder
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//!
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//! However, it has been adopted to fit the Dioxus Props builder pattern.
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//!
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//! For dioxus, we make a few changes:
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//! - [ ] automatically implement Into<Option> on the setters (IE the strip setter option)
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//! - [ ] automatically implement a default of none for optional fields (those explicitly wrapped with Option<T>)
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use proc_macro2::TokenStream;
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use syn::parse::Error;
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use syn::spanned::Spanned;
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use quote::quote;
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pub fn impl_my_derive(ast: &syn::DeriveInput) -> Result<TokenStream, Error> {
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let data = match &ast.data {
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syn::Data::Struct(data) => match &data.fields {
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syn::Fields::Named(fields) => {
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let struct_info = struct_info::StructInfo::new(ast, fields.named.iter())?;
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let builder_creation = struct_info.builder_creation_impl()?;
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let conversion_helper = struct_info.conversion_helper_impl()?;
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let fields = struct_info
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.included_fields()
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.map(|f| struct_info.field_impl(f))
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.collect::<Result<Vec<_>, _>>()?;
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let fields = quote!(#(#fields)*).into_iter();
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let required_fields = struct_info
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.included_fields()
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.filter(|f| f.builder_attr.default.is_none())
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.map(|f| struct_info.required_field_impl(f))
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.collect::<Result<Vec<_>, _>>()?;
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let build_method = struct_info.build_method_impl();
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quote! {
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#builder_creation
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#conversion_helper
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#( #fields )*
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#( #required_fields )*
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#build_method
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}
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}
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syn::Fields::Unnamed(_) => {
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return Err(Error::new(
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ast.span(),
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"Props is not supported for tuple structs",
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))
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}
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syn::Fields::Unit => {
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return Err(Error::new(
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ast.span(),
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"Props is not supported for unit structs",
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))
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}
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},
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syn::Data::Enum(_) => {
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return Err(Error::new(ast.span(), "Props is not supported for enums"))
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}
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syn::Data::Union(_) => {
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return Err(Error::new(ast.span(), "Props is not supported for unions"))
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}
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};
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Ok(data)
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}
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mod util {
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use quote::ToTokens;
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pub fn path_to_single_string(path: &syn::Path) -> Option<String> {
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if path.leading_colon.is_some() {
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return None;
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}
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let mut it = path.segments.iter();
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let segment = it.next()?;
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if it.next().is_some() {
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// Multipart path
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return None;
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}
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if segment.arguments != syn::PathArguments::None {
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return None;
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}
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Some(segment.ident.to_string())
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}
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pub fn expr_to_single_string(expr: &syn::Expr) -> Option<String> {
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if let syn::Expr::Path(path) = expr {
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path_to_single_string(&path.path)
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} else {
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None
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}
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}
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pub fn ident_to_type(ident: syn::Ident) -> syn::Type {
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let mut path = syn::Path {
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leading_colon: None,
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segments: Default::default(),
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};
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path.segments.push(syn::PathSegment {
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ident,
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arguments: Default::default(),
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});
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syn::Type::Path(syn::TypePath { qself: None, path })
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}
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pub fn empty_type() -> syn::Type {
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syn::TypeTuple {
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paren_token: Default::default(),
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elems: Default::default(),
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}
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.into()
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}
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pub fn type_tuple(elems: impl Iterator<Item = syn::Type>) -> syn::TypeTuple {
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let mut result = syn::TypeTuple {
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paren_token: Default::default(),
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elems: elems.collect(),
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};
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if !result.elems.empty_or_trailing() {
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result.elems.push_punct(Default::default());
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}
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result
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}
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pub fn empty_type_tuple() -> syn::TypeTuple {
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syn::TypeTuple {
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paren_token: Default::default(),
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elems: Default::default(),
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}
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}
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pub fn make_punctuated_single<T, P: Default>(value: T) -> syn::punctuated::Punctuated<T, P> {
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let mut punctuated = syn::punctuated::Punctuated::new();
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punctuated.push(value);
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punctuated
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}
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pub fn modify_types_generics_hack<F>(
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ty_generics: &syn::TypeGenerics,
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mut mutator: F,
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) -> syn::AngleBracketedGenericArguments
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where
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F: FnMut(&mut syn::punctuated::Punctuated<syn::GenericArgument, syn::token::Comma>),
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{
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let mut abga: syn::AngleBracketedGenericArguments =
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syn::parse(ty_generics.clone().into_token_stream().into()).unwrap_or_else(|_| {
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syn::AngleBracketedGenericArguments {
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colon2_token: None,
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lt_token: Default::default(),
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args: Default::default(),
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gt_token: Default::default(),
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}
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});
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mutator(&mut abga.args);
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abga
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}
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pub fn strip_raw_ident_prefix(mut name: String) -> String {
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if name.starts_with("r#") {
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name.replace_range(0..2, "");
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}
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name
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}
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}
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mod field_info {
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use crate::props::type_from_inside_option;
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use proc_macro2::TokenStream;
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use quote::quote;
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use syn::parse::Error;
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use syn::spanned::Spanned;
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use super::util::{
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expr_to_single_string, ident_to_type, path_to_single_string, strip_raw_ident_prefix,
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};
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#[derive(Debug)]
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pub struct FieldInfo<'a> {
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pub ordinal: usize,
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pub name: &'a syn::Ident,
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pub generic_ident: syn::Ident,
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pub ty: &'a syn::Type,
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pub builder_attr: FieldBuilderAttr,
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}
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impl<'a> FieldInfo<'a> {
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pub fn new(
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ordinal: usize,
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field: &syn::Field,
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field_defaults: FieldBuilderAttr,
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) -> Result<FieldInfo, Error> {
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if let Some(ref name) = field.ident {
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let mut builder_attr = field_defaults.with(&field.attrs)?;
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// children field is automatically defaulted to None
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if name == "children" {
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builder_attr.default =
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Some(syn::parse(quote!(::dioxus::core::VNode::empty()).into()).unwrap());
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}
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// auto detect optional
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let strip_option_auto = builder_attr.strip_option
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|| !builder_attr.ignore_option
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&& type_from_inside_option(&field.ty, true).is_some();
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if !builder_attr.strip_option && strip_option_auto {
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builder_attr.strip_option = true;
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builder_attr.default =
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Some(syn::parse(quote!(Default::default()).into()).unwrap());
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}
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Ok(FieldInfo {
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ordinal,
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name,
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generic_ident: syn::Ident::new(
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&format!("__{}", strip_raw_ident_prefix(name.to_string())),
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proc_macro2::Span::call_site(),
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),
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ty: &field.ty,
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builder_attr,
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})
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} else {
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Err(Error::new(field.span(), "Nameless field in struct"))
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}
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}
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pub fn generic_ty_param(&self) -> syn::GenericParam {
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syn::GenericParam::Type(self.generic_ident.clone().into())
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}
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pub fn type_ident(&self) -> syn::Type {
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ident_to_type(self.generic_ident.clone())
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}
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pub fn tuplized_type_ty_param(&self) -> syn::Type {
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let mut types = syn::punctuated::Punctuated::default();
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types.push(self.ty.clone());
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types.push_punct(Default::default());
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syn::TypeTuple {
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paren_token: Default::default(),
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elems: types,
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}
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.into()
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}
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pub fn type_from_inside_option(&self, check_option_name: bool) -> Option<&syn::Type> {
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type_from_inside_option(self.ty, check_option_name)
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}
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}
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#[derive(Debug, Default, Clone)]
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pub struct FieldBuilderAttr {
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pub default: Option<syn::Expr>,
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pub doc: Option<syn::Expr>,
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pub skip: bool,
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pub auto_into: bool,
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pub strip_option: bool,
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pub ignore_option: bool,
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}
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impl FieldBuilderAttr {
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pub fn with(mut self, attrs: &[syn::Attribute]) -> Result<Self, Error> {
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let mut skip_tokens = None;
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for attr in attrs {
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if path_to_single_string(&attr.path).as_deref() != Some("props") {
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continue;
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}
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if attr.tokens.is_empty() {
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continue;
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}
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let as_expr: syn::Expr = syn::parse2(attr.tokens.clone())?;
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match as_expr {
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syn::Expr::Paren(body) => {
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self.apply_meta(*body.expr)?;
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}
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syn::Expr::Tuple(body) => {
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for expr in body.elems.into_iter() {
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self.apply_meta(expr)?;
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}
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}
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_ => {
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return Err(Error::new_spanned(attr.tokens.clone(), "Expected (<...>)"));
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}
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}
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// Stash its span for later (we don’t yet know if it’ll be an error)
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if self.skip && skip_tokens.is_none() {
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skip_tokens = Some(attr.tokens.clone());
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}
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}
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if self.skip && self.default.is_none() {
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return Err(Error::new_spanned(
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skip_tokens.unwrap(),
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"#[props(skip)] must be accompanied by default or default_code",
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));
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}
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Ok(self)
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}
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pub fn apply_meta(&mut self, expr: syn::Expr) -> Result<(), Error> {
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match expr {
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// #[props(default = "...")]
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syn::Expr::Assign(assign) => {
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let name = expr_to_single_string(&assign.left)
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.ok_or_else(|| Error::new_spanned(&assign.left, "Expected identifier"))?;
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match name.as_str() {
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"default" => {
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self.default = Some(*assign.right);
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Ok(())
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}
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"doc" => {
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self.doc = Some(*assign.right);
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Ok(())
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}
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"default_code" => {
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if let syn::Expr::Lit(syn::ExprLit {
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lit: syn::Lit::Str(code),
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..
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}) = *assign.right
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{
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use std::str::FromStr;
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let tokenized_code = TokenStream::from_str(&code.value())?;
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self.default = Some(
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syn::parse(tokenized_code.into())
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.map_err(|e| Error::new_spanned(code, format!("{}", e)))?,
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);
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} else {
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return Err(Error::new_spanned(assign.right, "Expected string"));
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}
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Ok(())
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}
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_ => Err(Error::new_spanned(
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&assign,
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format!("Unknown parameter {:?}", name),
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)),
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}
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}
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// #[props(default)]
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syn::Expr::Path(path) => {
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let name = path_to_single_string(&path.path)
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.ok_or_else(|| Error::new_spanned(&path, "Expected identifier"))?;
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match name.as_str() {
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"default" => {
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self.default =
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Some(syn::parse(quote!(Default::default()).into()).unwrap());
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Ok(())
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}
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"optional" => {
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self.default =
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Some(syn::parse(quote!(Default::default()).into()).unwrap());
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self.strip_option = true;
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Ok(())
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}
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_ => {
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macro_rules! handle_fields {
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( $( $flag:expr, $field:ident, $already:expr; )* ) => {
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match name.as_str() {
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$(
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$flag => {
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if self.$field {
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Err(Error::new(path.span(), concat!("Illegal setting - field is already ", $already)))
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} else {
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self.$field = true;
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Ok(())
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}
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}
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)*
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_ => Err(Error::new_spanned(
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&path,
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format!("Unknown setter parameter {:?}", name),
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))
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}
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}
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}
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handle_fields!(
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"skip", skip, "skipped";
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"into", auto_into, "calling into() on the argument";
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"strip_option", strip_option, "putting the argument in Some(...)";
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)
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}
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}
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}
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syn::Expr::Unary(syn::ExprUnary {
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op: syn::UnOp::Not(_),
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expr,
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..
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}) => {
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if let syn::Expr::Path(path) = *expr {
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let name = path_to_single_string(&path.path)
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.ok_or_else(|| Error::new_spanned(&path, "Expected identifier"))?;
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match name.as_str() {
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"default" => {
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self.default = None;
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Ok(())
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}
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"doc" => {
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self.doc = None;
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Ok(())
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}
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"skip" => {
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self.skip = false;
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Ok(())
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}
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"auto_into" => {
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self.auto_into = false;
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Ok(())
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}
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"optional" => {
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self.strip_option = false;
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self.ignore_option = true;
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Ok(())
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}
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_ => Err(Error::new_spanned(path, "Unknown setting".to_owned())),
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}
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} else {
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Err(Error::new_spanned(
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expr,
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"Expected simple identifier".to_owned(),
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))
|
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}
|
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}
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_ => Err(Error::new_spanned(expr, "Expected (<...>=<...>)")),
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}
|
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}
|
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}
|
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}
|
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fn type_from_inside_option(ty: &syn::Type, check_option_name: bool) -> Option<&syn::Type> {
|
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let path = if let syn::Type::Path(type_path) = ty {
|
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if type_path.qself.is_some() {
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return None;
|
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} else {
|
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&type_path.path
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}
|
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} else {
|
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return None;
|
||
};
|
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let segment = path.segments.last()?;
|
||
if check_option_name && segment.ident != "Option" {
|
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return None;
|
||
}
|
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let generic_params =
|
||
if let syn::PathArguments::AngleBracketed(generic_params) = &segment.arguments {
|
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generic_params
|
||
} else {
|
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return None;
|
||
};
|
||
if let syn::GenericArgument::Type(ty) = generic_params.args.first()? {
|
||
Some(ty)
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
mod struct_info {
|
||
use proc_macro2::TokenStream;
|
||
use quote::quote;
|
||
use syn::parse::Error;
|
||
|
||
use super::field_info::{FieldBuilderAttr, FieldInfo};
|
||
use super::util::{
|
||
empty_type, empty_type_tuple, expr_to_single_string, make_punctuated_single,
|
||
modify_types_generics_hack, path_to_single_string, strip_raw_ident_prefix, type_tuple,
|
||
};
|
||
|
||
#[derive(Debug)]
|
||
pub struct StructInfo<'a> {
|
||
pub vis: &'a syn::Visibility,
|
||
pub name: &'a syn::Ident,
|
||
pub generics: &'a syn::Generics,
|
||
pub fields: Vec<FieldInfo<'a>>,
|
||
|
||
pub builder_attr: TypeBuilderAttr,
|
||
pub builder_name: syn::Ident,
|
||
pub conversion_helper_trait_name: syn::Ident,
|
||
pub core: syn::Ident,
|
||
}
|
||
|
||
impl<'a> StructInfo<'a> {
|
||
pub fn included_fields(&self) -> impl Iterator<Item = &FieldInfo<'a>> {
|
||
self.fields.iter().filter(|f| !f.builder_attr.skip)
|
||
}
|
||
|
||
pub fn new(
|
||
ast: &'a syn::DeriveInput,
|
||
fields: impl Iterator<Item = &'a syn::Field>,
|
||
) -> Result<StructInfo<'a>, Error> {
|
||
let builder_attr = TypeBuilderAttr::new(&ast.attrs)?;
|
||
let builder_name = strip_raw_ident_prefix(format!("{}Builder", ast.ident));
|
||
Ok(StructInfo {
|
||
vis: &ast.vis,
|
||
name: &ast.ident,
|
||
generics: &ast.generics,
|
||
fields: fields
|
||
.enumerate()
|
||
.map(|(i, f)| FieldInfo::new(i, f, builder_attr.field_defaults.clone()))
|
||
.collect::<Result<_, _>>()?,
|
||
builder_attr,
|
||
builder_name: syn::Ident::new(&builder_name, proc_macro2::Span::call_site()),
|
||
conversion_helper_trait_name: syn::Ident::new(
|
||
&format!("{}_Optional", builder_name),
|
||
proc_macro2::Span::call_site(),
|
||
),
|
||
core: syn::Ident::new(
|
||
&format!("{}_core", builder_name),
|
||
proc_macro2::Span::call_site(),
|
||
),
|
||
})
|
||
}
|
||
|
||
fn modify_generics<F: FnMut(&mut syn::Generics)>(&self, mut mutator: F) -> syn::Generics {
|
||
let mut generics = self.generics.clone();
|
||
mutator(&mut generics);
|
||
generics
|
||
}
|
||
|
||
pub fn builder_creation_impl(&self) -> Result<TokenStream, Error> {
|
||
let StructInfo {
|
||
ref vis,
|
||
ref name,
|
||
ref builder_name,
|
||
..
|
||
} = *self;
|
||
|
||
// we're generating stuff that goes into unsafe code here
|
||
// we use the heuristic: are there *any* generic parameters?
|
||
// If so, then they might have non-static lifetimes and we can't compare two generic things that *might borrow*
|
||
// Therefore, we will generate code that shortcircuits the "comparison" in memoization
|
||
let are_there_generics = !self.generics.params.is_empty();
|
||
|
||
let (impl_generics, ty_generics, where_clause) = self.generics.split_for_impl();
|
||
let all_fields_param = syn::GenericParam::Type(
|
||
syn::Ident::new("TypedBuilderFields", proc_macro2::Span::call_site()).into(),
|
||
);
|
||
let b_generics = self.modify_generics(|g| {
|
||
g.params.insert(0, all_fields_param.clone());
|
||
});
|
||
let empties_tuple = type_tuple(self.included_fields().map(|_| empty_type()));
|
||
let generics_with_empty = modify_types_generics_hack(&ty_generics, |args| {
|
||
args.insert(0, syn::GenericArgument::Type(empties_tuple.clone().into()));
|
||
});
|
||
let phantom_generics = self.generics.params.iter().map(|param| match param {
|
||
syn::GenericParam::Lifetime(lifetime) => {
|
||
let lifetime = &lifetime.lifetime;
|
||
quote!(core::marker::PhantomData<&#lifetime ()>)
|
||
}
|
||
syn::GenericParam::Type(ty) => {
|
||
let ty = &ty.ident;
|
||
quote!(core::marker::PhantomData<#ty>)
|
||
}
|
||
syn::GenericParam::Const(_cnst) => {
|
||
quote!()
|
||
}
|
||
});
|
||
let builder_method_doc = match self.builder_attr.builder_method_doc {
|
||
Some(ref doc) => quote!(#doc),
|
||
None => {
|
||
let doc = format!(
|
||
"
|
||
Create a builder for building `{name}`.
|
||
On the builder, call {setters} to set the values of the fields.
|
||
Finally, call `.build()` to create the instance of `{name}`.
|
||
",
|
||
name = self.name,
|
||
setters = {
|
||
let mut result = String::new();
|
||
let mut is_first = true;
|
||
for field in self.included_fields() {
|
||
use std::fmt::Write;
|
||
if is_first {
|
||
is_first = false;
|
||
} else {
|
||
write!(&mut result, ", ").unwrap();
|
||
}
|
||
write!(&mut result, "`.{}(...)`", field.name).unwrap();
|
||
if field.builder_attr.default.is_some() {
|
||
write!(&mut result, "(optional)").unwrap();
|
||
}
|
||
}
|
||
result
|
||
}
|
||
);
|
||
quote!(#doc)
|
||
}
|
||
};
|
||
let builder_type_doc = if self.builder_attr.doc {
|
||
match self.builder_attr.builder_type_doc {
|
||
Some(ref doc) => quote!(#[doc = #doc]),
|
||
None => {
|
||
let doc = format!(
|
||
"Builder for [`{name}`] instances.\n\nSee [`{name}::builder()`] for more info.",
|
||
name = name
|
||
);
|
||
quote!(#[doc = #doc])
|
||
}
|
||
}
|
||
} else {
|
||
quote!(#[doc(hidden)])
|
||
};
|
||
|
||
let (b_generics_impl, b_generics_ty, b_generics_where_extras_predicates) =
|
||
b_generics.split_for_impl();
|
||
let mut b_generics_where: syn::WhereClause = syn::parse2(quote! {
|
||
where TypedBuilderFields: Clone
|
||
})?;
|
||
if let Some(predicates) = b_generics_where_extras_predicates {
|
||
b_generics_where
|
||
.predicates
|
||
.extend(predicates.predicates.clone());
|
||
}
|
||
|
||
let can_memoize = match are_there_generics {
|
||
true => quote! { false },
|
||
false => quote! { self == other },
|
||
};
|
||
|
||
let is_static = match are_there_generics {
|
||
true => quote! { false },
|
||
false => quote! { true },
|
||
};
|
||
|
||
Ok(quote! {
|
||
impl #impl_generics #name #ty_generics #where_clause {
|
||
#[doc = #builder_method_doc]
|
||
#[allow(dead_code)]
|
||
#vis fn builder() -> #builder_name #generics_with_empty {
|
||
#builder_name {
|
||
fields: #empties_tuple,
|
||
_phantom: core::default::Default::default(),
|
||
}
|
||
}
|
||
}
|
||
|
||
#[must_use]
|
||
#builder_type_doc
|
||
#[allow(dead_code, non_camel_case_types, non_snake_case)]
|
||
#vis struct #builder_name #b_generics {
|
||
fields: #all_fields_param,
|
||
_phantom: (#( #phantom_generics ),*),
|
||
}
|
||
|
||
impl #b_generics_impl Clone for #builder_name #b_generics_ty #b_generics_where {
|
||
fn clone(&self) -> Self {
|
||
Self {
|
||
fields: self.fields.clone(),
|
||
_phantom: Default::default(),
|
||
}
|
||
}
|
||
}
|
||
|
||
impl #impl_generics dioxus::prelude::Properties for #name #ty_generics
|
||
#b_generics_where_extras_predicates
|
||
{
|
||
type Builder = #builder_name #generics_with_empty;
|
||
const IS_STATIC: bool = #is_static;
|
||
fn builder() -> Self::Builder {
|
||
#name::builder()
|
||
}
|
||
unsafe fn memoize(&self, other: &Self) -> bool {
|
||
#can_memoize
|
||
}
|
||
}
|
||
|
||
})
|
||
}
|
||
|
||
// TODO: once the proc-macro crate limitation is lifted, make this an util trait of this
|
||
// crate.
|
||
pub fn conversion_helper_impl(&self) -> Result<TokenStream, Error> {
|
||
let trait_name = &self.conversion_helper_trait_name;
|
||
Ok(quote! {
|
||
#[doc(hidden)]
|
||
#[allow(dead_code, non_camel_case_types, non_snake_case)]
|
||
pub trait #trait_name<T> {
|
||
fn into_value<F: FnOnce() -> T>(self, default: F) -> T;
|
||
}
|
||
|
||
impl<T> #trait_name<T> for () {
|
||
fn into_value<F: FnOnce() -> T>(self, default: F) -> T {
|
||
default()
|
||
}
|
||
}
|
||
|
||
impl<T> #trait_name<T> for (T,) {
|
||
fn into_value<F: FnOnce() -> T>(self, _: F) -> T {
|
||
self.0
|
||
}
|
||
}
|
||
})
|
||
}
|
||
|
||
pub fn field_impl(&self, field: &FieldInfo) -> Result<TokenStream, Error> {
|
||
let StructInfo {
|
||
ref builder_name, ..
|
||
} = *self;
|
||
|
||
let descructuring = self.included_fields().map(|f| {
|
||
if f.ordinal == field.ordinal {
|
||
quote!(_)
|
||
} else {
|
||
let name = f.name;
|
||
quote!(#name)
|
||
}
|
||
});
|
||
let reconstructing = self.included_fields().map(|f| f.name);
|
||
|
||
let &FieldInfo {
|
||
name: ref field_name,
|
||
ty: ref field_type,
|
||
..
|
||
} = field;
|
||
let mut ty_generics: Vec<syn::GenericArgument> = self
|
||
.generics
|
||
.params
|
||
.iter()
|
||
.map(|generic_param| match generic_param {
|
||
syn::GenericParam::Type(type_param) => {
|
||
let ident = type_param.ident.clone();
|
||
syn::parse(quote!(#ident).into()).unwrap()
|
||
}
|
||
syn::GenericParam::Lifetime(lifetime_def) => {
|
||
syn::GenericArgument::Lifetime(lifetime_def.lifetime.clone())
|
||
}
|
||
syn::GenericParam::Const(const_param) => {
|
||
let ident = const_param.ident.clone();
|
||
syn::parse(quote!(#ident).into()).unwrap()
|
||
}
|
||
})
|
||
.collect();
|
||
let mut target_generics_tuple = empty_type_tuple();
|
||
let mut ty_generics_tuple = empty_type_tuple();
|
||
let generics = self.modify_generics(|g| {
|
||
let index_after_lifetime_in_generics = g
|
||
.params
|
||
.iter()
|
||
.filter(|arg| matches!(arg, syn::GenericParam::Lifetime(_)))
|
||
.count();
|
||
for f in self.included_fields() {
|
||
if f.ordinal == field.ordinal {
|
||
ty_generics_tuple.elems.push_value(empty_type());
|
||
target_generics_tuple
|
||
.elems
|
||
.push_value(f.tuplized_type_ty_param());
|
||
} else {
|
||
g.params
|
||
.insert(index_after_lifetime_in_generics, f.generic_ty_param());
|
||
let generic_argument: syn::Type = f.type_ident();
|
||
ty_generics_tuple.elems.push_value(generic_argument.clone());
|
||
target_generics_tuple.elems.push_value(generic_argument);
|
||
}
|
||
ty_generics_tuple.elems.push_punct(Default::default());
|
||
target_generics_tuple.elems.push_punct(Default::default());
|
||
}
|
||
});
|
||
let mut target_generics = ty_generics.clone();
|
||
let index_after_lifetime_in_generics = target_generics
|
||
.iter()
|
||
.filter(|arg| matches!(arg, syn::GenericArgument::Lifetime(_)))
|
||
.count();
|
||
target_generics.insert(
|
||
index_after_lifetime_in_generics,
|
||
syn::GenericArgument::Type(target_generics_tuple.into()),
|
||
);
|
||
ty_generics.insert(
|
||
index_after_lifetime_in_generics,
|
||
syn::GenericArgument::Type(ty_generics_tuple.into()),
|
||
);
|
||
let (impl_generics, _, where_clause) = generics.split_for_impl();
|
||
let doc = match field.builder_attr.doc {
|
||
Some(ref doc) => quote!(#[doc = #doc]),
|
||
None => quote!(),
|
||
};
|
||
|
||
// NOTE: both auto_into and strip_option affect `arg_type` and `arg_expr`, but the order of
|
||
// nesting is different so we have to do this little dance.
|
||
let arg_type = if field.builder_attr.strip_option {
|
||
field.type_from_inside_option(false).ok_or_else(|| {
|
||
Error::new_spanned(
|
||
field_type,
|
||
"can't `strip_option` - field is not `Option<...>`",
|
||
)
|
||
})?
|
||
} else {
|
||
field_type
|
||
};
|
||
let (arg_type, arg_expr) = if field.builder_attr.auto_into {
|
||
(
|
||
quote!(impl core::convert::Into<#arg_type>),
|
||
quote!(#field_name.into()),
|
||
)
|
||
} else {
|
||
(quote!(#arg_type), quote!(#field_name))
|
||
};
|
||
let arg_expr = if field.builder_attr.strip_option {
|
||
quote!(Some(#arg_expr))
|
||
} else {
|
||
arg_expr
|
||
};
|
||
|
||
let repeated_fields_error_type_name = syn::Ident::new(
|
||
&format!(
|
||
"{}_Error_Repeated_field_{}",
|
||
builder_name,
|
||
strip_raw_ident_prefix(field_name.to_string())
|
||
),
|
||
proc_macro2::Span::call_site(),
|
||
);
|
||
let repeated_fields_error_message = format!("Repeated field {}", field_name);
|
||
|
||
Ok(quote! {
|
||
#[allow(dead_code, non_camel_case_types, missing_docs)]
|
||
impl #impl_generics #builder_name < #( #ty_generics ),* > #where_clause {
|
||
#doc
|
||
pub fn #field_name (self, #field_name: #arg_type) -> #builder_name < #( #target_generics ),* > {
|
||
let #field_name = (#arg_expr,);
|
||
let ( #(#descructuring,)* ) = self.fields;
|
||
#builder_name {
|
||
fields: ( #(#reconstructing,)* ),
|
||
_phantom: self._phantom,
|
||
}
|
||
}
|
||
}
|
||
#[doc(hidden)]
|
||
#[allow(dead_code, non_camel_case_types, non_snake_case)]
|
||
pub enum #repeated_fields_error_type_name {}
|
||
#[doc(hidden)]
|
||
#[allow(dead_code, non_camel_case_types, missing_docs)]
|
||
impl #impl_generics #builder_name < #( #target_generics ),* > #where_clause {
|
||
#[deprecated(
|
||
note = #repeated_fields_error_message
|
||
)]
|
||
pub fn #field_name (self, _: #repeated_fields_error_type_name) -> #builder_name < #( #target_generics ),* > {
|
||
self
|
||
}
|
||
}
|
||
})
|
||
}
|
||
|
||
pub fn required_field_impl(&self, field: &FieldInfo) -> Result<TokenStream, Error> {
|
||
let StructInfo {
|
||
ref name,
|
||
ref builder_name,
|
||
..
|
||
} = self;
|
||
|
||
let FieldInfo {
|
||
name: ref field_name,
|
||
..
|
||
} = field;
|
||
let mut builder_generics: Vec<syn::GenericArgument> = self
|
||
.generics
|
||
.params
|
||
.iter()
|
||
.map(|generic_param| match generic_param {
|
||
syn::GenericParam::Type(type_param) => {
|
||
let ident = &type_param.ident;
|
||
syn::parse(quote!(#ident).into()).unwrap()
|
||
}
|
||
syn::GenericParam::Lifetime(lifetime_def) => {
|
||
syn::GenericArgument::Lifetime(lifetime_def.lifetime.clone())
|
||
}
|
||
syn::GenericParam::Const(const_param) => {
|
||
let ident = &const_param.ident;
|
||
syn::parse(quote!(#ident).into()).unwrap()
|
||
}
|
||
})
|
||
.collect();
|
||
let mut builder_generics_tuple = empty_type_tuple();
|
||
let generics = self.modify_generics(|g| {
|
||
let index_after_lifetime_in_generics = g
|
||
.params
|
||
.iter()
|
||
.filter(|arg| matches!(arg, syn::GenericParam::Lifetime(_)))
|
||
.count();
|
||
for f in self.included_fields() {
|
||
if f.builder_attr.default.is_some() {
|
||
// `f` is not mandatory - it does not have it's own fake `build` method, so `field` will need
|
||
// to warn about missing `field` whether or not `f` is set.
|
||
assert!(
|
||
f.ordinal != field.ordinal,
|
||
"`required_field_impl` called for optional field {}",
|
||
field.name
|
||
);
|
||
g.params
|
||
.insert(index_after_lifetime_in_generics, f.generic_ty_param());
|
||
builder_generics_tuple.elems.push_value(f.type_ident());
|
||
} else if f.ordinal < field.ordinal {
|
||
// Only add a `build` method that warns about missing `field` if `f` is set. If `f` is not set,
|
||
// `f`'s `build` method will warn, since it appears earlier in the argument list.
|
||
builder_generics_tuple
|
||
.elems
|
||
.push_value(f.tuplized_type_ty_param());
|
||
} else if f.ordinal == field.ordinal {
|
||
builder_generics_tuple.elems.push_value(empty_type());
|
||
} else {
|
||
// `f` appears later in the argument list after `field`, so if they are both missing we will
|
||
// show a warning for `field` and not for `f` - which means this warning should appear whether
|
||
// or not `f` is set.
|
||
g.params
|
||
.insert(index_after_lifetime_in_generics, f.generic_ty_param());
|
||
builder_generics_tuple.elems.push_value(f.type_ident());
|
||
}
|
||
|
||
builder_generics_tuple.elems.push_punct(Default::default());
|
||
}
|
||
});
|
||
|
||
let index_after_lifetime_in_generics = builder_generics
|
||
.iter()
|
||
.filter(|arg| matches!(arg, syn::GenericArgument::Lifetime(_)))
|
||
.count();
|
||
builder_generics.insert(
|
||
index_after_lifetime_in_generics,
|
||
syn::GenericArgument::Type(builder_generics_tuple.into()),
|
||
);
|
||
let (impl_generics, _, where_clause) = generics.split_for_impl();
|
||
let (_, ty_generics, _) = self.generics.split_for_impl();
|
||
|
||
let early_build_error_type_name = syn::Ident::new(
|
||
&format!(
|
||
"{}_Error_Missing_required_field_{}",
|
||
builder_name,
|
||
strip_raw_ident_prefix(field_name.to_string())
|
||
),
|
||
proc_macro2::Span::call_site(),
|
||
);
|
||
let early_build_error_message = format!("Missing required field {}", field_name);
|
||
|
||
Ok(quote! {
|
||
#[doc(hidden)]
|
||
#[allow(dead_code, non_camel_case_types, non_snake_case)]
|
||
pub enum #early_build_error_type_name {}
|
||
#[doc(hidden)]
|
||
#[allow(dead_code, non_camel_case_types, missing_docs, clippy::panic)]
|
||
impl #impl_generics #builder_name < #( #builder_generics ),* > #where_clause {
|
||
#[deprecated(
|
||
note = #early_build_error_message
|
||
)]
|
||
pub fn build(self, _: #early_build_error_type_name) -> #name #ty_generics {
|
||
panic!();
|
||
}
|
||
}
|
||
})
|
||
}
|
||
|
||
pub fn build_method_impl(&self) -> TokenStream {
|
||
let StructInfo {
|
||
ref name,
|
||
ref builder_name,
|
||
..
|
||
} = *self;
|
||
|
||
let generics = self.modify_generics(|g| {
|
||
let index_after_lifetime_in_generics = g
|
||
.params
|
||
.iter()
|
||
.filter(|arg| matches!(arg, syn::GenericParam::Lifetime(_)))
|
||
.count();
|
||
for field in self.included_fields() {
|
||
if field.builder_attr.default.is_some() {
|
||
let trait_ref = syn::TraitBound {
|
||
paren_token: None,
|
||
lifetimes: None,
|
||
modifier: syn::TraitBoundModifier::None,
|
||
path: syn::PathSegment {
|
||
ident: self.conversion_helper_trait_name.clone(),
|
||
arguments: syn::PathArguments::AngleBracketed(
|
||
syn::AngleBracketedGenericArguments {
|
||
colon2_token: None,
|
||
lt_token: Default::default(),
|
||
args: make_punctuated_single(syn::GenericArgument::Type(
|
||
field.ty.clone(),
|
||
)),
|
||
gt_token: Default::default(),
|
||
},
|
||
),
|
||
}
|
||
.into(),
|
||
};
|
||
let mut generic_param: syn::TypeParam = field.generic_ident.clone().into();
|
||
generic_param.bounds.push(trait_ref.into());
|
||
g.params
|
||
.insert(index_after_lifetime_in_generics, generic_param.into());
|
||
}
|
||
}
|
||
});
|
||
let (impl_generics, _, _) = generics.split_for_impl();
|
||
|
||
let (_, ty_generics, where_clause) = self.generics.split_for_impl();
|
||
|
||
let modified_ty_generics = modify_types_generics_hack(&ty_generics, |args| {
|
||
args.insert(
|
||
0,
|
||
syn::GenericArgument::Type(
|
||
type_tuple(self.included_fields().map(|field| {
|
||
if field.builder_attr.default.is_some() {
|
||
field.type_ident()
|
||
} else {
|
||
field.tuplized_type_ty_param()
|
||
}
|
||
}))
|
||
.into(),
|
||
),
|
||
);
|
||
});
|
||
|
||
let descructuring = self.included_fields().map(|f| f.name);
|
||
|
||
let helper_trait_name = &self.conversion_helper_trait_name;
|
||
// The default of a field can refer to earlier-defined fields, which we handle by
|
||
// writing out a bunch of `let` statements first, which can each refer to earlier ones.
|
||
// This means that field ordering may actually be significant, which isn’t ideal. We could
|
||
// relax that restriction by calculating a DAG of field default dependencies and
|
||
// reordering based on that, but for now this much simpler thing is a reasonable approach.
|
||
let assignments = self.fields.iter().map(|field| {
|
||
let name = &field.name;
|
||
if let Some(ref default) = field.builder_attr.default {
|
||
if field.builder_attr.skip {
|
||
quote!(let #name = #default;)
|
||
} else {
|
||
quote!(let #name = #helper_trait_name::into_value(#name, || #default);)
|
||
}
|
||
} else {
|
||
quote!(let #name = #name.0;)
|
||
}
|
||
});
|
||
let field_names = self.fields.iter().map(|field| field.name);
|
||
let doc = if self.builder_attr.doc {
|
||
match self.builder_attr.build_method_doc {
|
||
Some(ref doc) => quote!(#[doc = #doc]),
|
||
None => {
|
||
// I’d prefer “a” or “an” to “its”, but determining which is grammatically
|
||
// correct is roughly impossible.
|
||
let doc =
|
||
format!("Finalise the builder and create its [`{}`] instance", name);
|
||
quote!(#[doc = #doc])
|
||
}
|
||
}
|
||
} else {
|
||
quote!()
|
||
};
|
||
quote!(
|
||
#[allow(dead_code, non_camel_case_types, missing_docs)]
|
||
impl #impl_generics #builder_name #modified_ty_generics #where_clause {
|
||
#doc
|
||
pub fn build(self) -> #name #ty_generics {
|
||
let ( #(#descructuring,)* ) = self.fields;
|
||
#( #assignments )*
|
||
#name {
|
||
#( #field_names ),*
|
||
}
|
||
}
|
||
}
|
||
)
|
||
}
|
||
}
|
||
|
||
#[derive(Debug, Default)]
|
||
pub struct TypeBuilderAttr {
|
||
/// Whether to show docs for the `TypeBuilder` type (rather than hiding them).
|
||
pub doc: bool,
|
||
|
||
/// Docs on the `Type::builder()` method.
|
||
pub builder_method_doc: Option<syn::Expr>,
|
||
|
||
/// Docs on the `TypeBuilder` type. Specifying this implies `doc`, but you can just specify
|
||
/// `doc` instead and a default value will be filled in here.
|
||
pub builder_type_doc: Option<syn::Expr>,
|
||
|
||
/// Docs on the `TypeBuilder.build()` method. Specifying this implies `doc`, but you can just
|
||
/// specify `doc` instead and a default value will be filled in here.
|
||
pub build_method_doc: Option<syn::Expr>,
|
||
|
||
pub field_defaults: FieldBuilderAttr,
|
||
}
|
||
|
||
impl TypeBuilderAttr {
|
||
pub fn new(attrs: &[syn::Attribute]) -> Result<TypeBuilderAttr, Error> {
|
||
let mut result = TypeBuilderAttr::default();
|
||
for attr in attrs {
|
||
if path_to_single_string(&attr.path).as_deref() != Some("builder") {
|
||
continue;
|
||
}
|
||
|
||
if attr.tokens.is_empty() {
|
||
continue;
|
||
}
|
||
let as_expr: syn::Expr = syn::parse2(attr.tokens.clone())?;
|
||
|
||
match as_expr {
|
||
syn::Expr::Paren(body) => {
|
||
result.apply_meta(*body.expr)?;
|
||
}
|
||
syn::Expr::Tuple(body) => {
|
||
for expr in body.elems.into_iter() {
|
||
result.apply_meta(expr)?;
|
||
}
|
||
}
|
||
_ => {
|
||
return Err(Error::new_spanned(attr.tokens.clone(), "Expected (<...>)"));
|
||
}
|
||
}
|
||
}
|
||
|
||
Ok(result)
|
||
}
|
||
|
||
fn apply_meta(&mut self, expr: syn::Expr) -> Result<(), Error> {
|
||
match expr {
|
||
syn::Expr::Assign(assign) => {
|
||
let name = expr_to_single_string(&assign.left)
|
||
.ok_or_else(|| Error::new_spanned(&assign.left, "Expected identifier"))?;
|
||
match name.as_str() {
|
||
"builder_method_doc" => {
|
||
self.builder_method_doc = Some(*assign.right);
|
||
Ok(())
|
||
}
|
||
"builder_type_doc" => {
|
||
self.builder_type_doc = Some(*assign.right);
|
||
self.doc = true;
|
||
Ok(())
|
||
}
|
||
"build_method_doc" => {
|
||
self.build_method_doc = Some(*assign.right);
|
||
self.doc = true;
|
||
Ok(())
|
||
}
|
||
_ => Err(Error::new_spanned(
|
||
&assign,
|
||
format!("Unknown parameter {:?}", name),
|
||
)),
|
||
}
|
||
}
|
||
syn::Expr::Path(path) => {
|
||
let name = path_to_single_string(&path.path)
|
||
.ok_or_else(|| Error::new_spanned(&path, "Expected identifier"))?;
|
||
match name.as_str() {
|
||
"doc" => {
|
||
self.doc = true;
|
||
Ok(())
|
||
}
|
||
_ => Err(Error::new_spanned(
|
||
&path,
|
||
format!("Unknown parameter {:?}", name),
|
||
)),
|
||
}
|
||
}
|
||
syn::Expr::Call(call) => {
|
||
let subsetting_name = if let syn::Expr::Path(path) = &*call.func {
|
||
path_to_single_string(&path.path)
|
||
} else {
|
||
None
|
||
}
|
||
.ok_or_else(|| {
|
||
let call_func = &call.func;
|
||
let call_func = quote!(#call_func);
|
||
Error::new_spanned(
|
||
&call.func,
|
||
format!("Illegal builder setting group {}", call_func),
|
||
)
|
||
})?;
|
||
match subsetting_name.as_str() {
|
||
"field_defaults" => {
|
||
for arg in call.args {
|
||
self.field_defaults.apply_meta(arg)?;
|
||
}
|
||
Ok(())
|
||
}
|
||
_ => Err(Error::new_spanned(
|
||
&call.func,
|
||
format!("Illegal builder setting group name {}", subsetting_name),
|
||
)),
|
||
}
|
||
}
|
||
_ => Err(Error::new_spanned(expr, "Expected (<...>=<...>)")),
|
||
}
|
||
}
|
||
}
|
||
}
|