Refactor and move check_components! implementation to cgp-macro-core (#239)

* Move check_components types

* Draft implement new CheckEntry

* Refactor to use new CheckEntry

* Fix clippy

* Fix span in delegate_and_check_components

* Use TypeWithGenerics in EvaluatedCheckEntry

* Migrate derive_check_components

* Fully migrate derive check components

Author: soareschen

crates/macros/cgp-macro-core/src/types/check_components/entries.rs

@@ -0,0 +1,29 @@
+use syn::parse::{Parse, ParseStream};
+use syn::punctuated::Punctuated;
+use syn::token::Comma;
+
+use crate::types::check_components::{CheckEntry, EvaluatedCheckEntry};
+
+pub struct CheckEntries {
+    pub entries: Punctuated<CheckEntry, Comma>,
+}
+
+impl CheckEntries {
+    pub fn eval(&self) -> Vec<EvaluatedCheckEntry> {
+        let mut evaluated_entries = Vec::new();
+
+        for entry in &self.entries {
+            evaluated_entries.extend(entry.eval());
+        }
+
+        evaluated_entries
+    }
+}
+
+impl Parse for CheckEntries {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let entries: Punctuated<CheckEntry, Comma> = Punctuated::parse_terminated(input)?;
+
+        Ok(Self { entries })
+    }
+}

crates/macros/cgp-macro-core/src/types/check_components/entry.rs

@@ -0,0 +1,82 @@
+use syn::parse::{Parse, ParseStream};
+use syn::spanned::Spanned;
+use syn::token::Colon;
+
+use crate::types::check_components::{CheckKey, CheckValue, EvaluatedCheckEntry, TypeWithGenerics};
+
+pub struct CheckEntry {
+    pub key: CheckKey,
+    pub value: Option<CheckValue>,
+}
+
+impl CheckEntry {
+    pub fn eval(&self) -> Vec<EvaluatedCheckEntry> {
+        let mut entries = Vec::new();
+
+        let keys = self.key.to_keys();
+
+        let component_types_count = keys.len();
+
+        for component_type in keys.iter() {
+            if let Some(value) = &self.value {
+                let values = value.to_values();
+
+                if values.is_empty() {
+                    entries.push(EvaluatedCheckEntry {
+                        key: component_type.clone(),
+                        value: None,
+                        span: component_type.span(),
+                    })
+                } else {
+                    let component_params_count = values.len();
+
+                    for component_param in values.iter() {
+                        let component_param_type = &component_param.ty;
+                        let component_param_generics = &component_param.generics;
+
+                        let span = if component_types_count >= component_params_count {
+                            component_type.span()
+                        } else {
+                            component_param_type.span()
+                        };
+
+                        entries.push(EvaluatedCheckEntry {
+                            key: component_type.clone(),
+                            value: Some(TypeWithGenerics {
+                                ty: component_param_type.clone(),
+                                generics: component_param_generics.clone(),
+                            }),
+                            span,
+                        })
+                    }
+                }
+            } else {
+                entries.push(EvaluatedCheckEntry {
+                    key: component_type.clone(),
+                    value: None,
+                    span: component_type.span(),
+                })
+            }
+        }
+
+        entries
+    }
+}
+
+impl Parse for CheckEntry {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let key = input.parse()?;
+
+        if input.peek(Colon) {
+            let _: Colon = input.parse()?;
+            let value = input.parse()?;
+
+            Ok(Self {
+                key,
+                value: Some(value),
+            })
+        } else {
+            Ok(Self { key, value: None })
+        }
+    }
+}

crates/macros/cgp-macro-core/src/types/check_components/evaluated_check_entry.rs

@@ -0,0 +1,10 @@
+use proc_macro2::Span;
+use syn::Type;
+
+use crate::types::check_components::TypeWithGenerics;
+
+pub struct EvaluatedCheckEntry {
+    pub key: Type,
+    pub value: Option<TypeWithGenerics>,
+    pub span: Span,
+}

crates/macros/cgp-macro-core/src/types/check_components/key.rs

@@ -0,0 +1,33 @@
+use syn::parse::{Parse, ParseStream};
+use syn::punctuated::Punctuated;
+use syn::token::{Bracket, Comma};
+use syn::{Type, bracketed};
+
+pub enum CheckKey {
+    Single(Type),
+    Multi(Punctuated<Type, Comma>),
+}
+
+impl CheckKey {
+    pub fn to_keys(&self) -> Vec<Type> {
+        match self {
+            Self::Single(key) => vec![key.clone()],
+            Self::Multi(keys) => Vec::from_iter(keys.iter().cloned()),
+        }
+    }
+}
+
+impl Parse for CheckKey {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        if input.peek(Bracket) {
+            let content;
+            bracketed!(content in input);
+
+            let keys: Punctuated<Type, Comma> = Punctuated::parse_terminated(&content)?;
+            Ok(Self::Multi(keys))
+        } else {
+            let key: Type = input.parse()?;
+            Ok(Self::Single(key))
+        }
+    }
+}

crates/macros/cgp-macro-core/src/types/check_components/mod.rs

@@ -0,0 +1,17 @@
+mod entries;
+mod entry;
+mod evaluated_check_entry;
+mod key;
+mod table;
+mod tables;
+mod type_with_generics;
+mod value;
+
+pub use entries::*;
+pub use entry::*;
+pub use evaluated_check_entry::*;
+pub use key::*;
+pub use table::*;
+pub use tables::*;
+pub use type_with_generics::*;
+pub use value::*;

crates/macros/cgp-macro-core/src/types/check_components/table.rs

@@ -0,0 +1,190 @@
+use proc_macro2::Span;
+use quote::ToTokens;
+use syn::parse::{Parse, ParseStream};
+use syn::punctuated::Punctuated;
+use syn::spanned::Spanned;
+use syn::token::{Comma, Lt, Pound, Where};
+use syn::{Attribute, Ident, Item, ItemImpl, ItemTrait, Type, WhereClause, braced, parse2};
+
+use crate::functions::merge_generics;
+use crate::parse_internal;
+use crate::types::check_components::{CheckEntries, EvaluatedCheckEntry, TypeWithGenerics};
+use crate::types::generics::ImplGenerics;
+use crate::types::ident::IdentWithTypeArgs;
+
+pub struct CheckComponentsTable {
+    pub check_providers: Option<Punctuated<Type, Comma>>,
+    pub impl_generics: ImplGenerics,
+    pub trait_name: Ident,
+    pub context_type: Type,
+    pub where_clause: WhereClause,
+    pub check_entries: CheckEntries,
+}
+
+impl CheckComponentsTable {
+    pub fn to_items(&self) -> syn::Result<Vec<Item>> {
+        let (item_trait, item_impls) = self.eval()?;
+
+        let mut items = vec![item_trait.into()];
+        items.extend(item_impls.into_iter().map(Into::into));
+
+        Ok(items)
+    }
+
+    pub fn eval(&self) -> syn::Result<(ItemTrait, Vec<ItemImpl>)> {
+        let mut item_impls = Vec::new();
+        let unit: Type = parse_internal!(());
+
+        let context_type = &self.context_type;
+        let trait_name = &self.trait_name;
+        let impl_generics = &self.impl_generics;
+        let where_clause = &self.where_clause;
+
+        let item_trait: ItemTrait = if self.check_providers.is_some() {
+            parse_internal! {
+                trait #trait_name <__Component__, __Params__: ?Sized>: IsProviderFor<__Component__, #context_type, __Params__> {}
+            }
+        } else {
+            parse_internal! {
+                trait #trait_name <__Component__, __Params__: ?Sized>: CanUseComponent<__Component__, __Params__> {}
+            }
+        };
+
+        let evaluated_entries = self.check_entries.eval();
+
+        for entry in evaluated_entries {
+            let EvaluatedCheckEntry {
+                key: component_type,
+                value: component_params,
+                span,
+            } = entry;
+
+            let self_types = if let Some(check_providers) = &self.check_providers {
+                Vec::from_iter(check_providers.iter().cloned())
+            } else {
+                // Override the span of the context type so that any unsatisfied constraint
+                // error is highlighted on the component type instead
+                let context_type = override_span(&span, context_type)?;
+                vec![context_type]
+            };
+
+            let TypeWithGenerics {
+                ty: component_param,
+                generics: check_generics,
+            } = component_params.unwrap_or_else(|| unit.clone().into());
+
+            let generics = merge_generics(&check_generics.generics, &impl_generics.generics);
+
+            let impl_generics = generics.split_for_impl().0;
+
+            for self_type in self_types {
+                let item_impl: ItemImpl = parse_internal! {
+                    impl #impl_generics
+                        #trait_name < #component_type, #component_param >
+                        for #self_type
+                    #where_clause
+                    {}
+                };
+
+                item_impls.push(item_impl);
+            }
+        }
+
+        Ok((item_trait, item_impls))
+    }
+}
+
+impl Parse for CheckComponentsTable {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let mut check_providers: Option<Punctuated<Type, Comma>> = None;
+        let mut m_check_trait_name: Option<Ident> = None;
+
+        if input.peek(Pound) {
+            let attributes = input.call(Attribute::parse_outer)?;
+
+            for attribute in attributes {
+                if attribute.path().is_ident("check_providers") {
+                    let provider_types: Punctuated<Type, Comma> =
+                        attribute.parse_args_with(Punctuated::parse_terminated)?;
+
+                    check_providers
+                        .get_or_insert_default()
+                        .extend(provider_types);
+                } else if attribute.path().is_ident("check_trait") {
+                    let check_trait_name: Ident = attribute.parse_args()?;
+
+                    if m_check_trait_name.is_some() {
+                        return Err(syn::Error::new(
+                            attribute.span(),
+                            "Multiple `#[check_trait]` attributes found. Expected at most one.",
+                        ));
+                    }
+
+                    m_check_trait_name = Some(check_trait_name);
+                } else {
+                    return Err(syn::Error::new(
+                        attribute.span(),
+                        format!("Invalid attribute {}", attribute.to_token_stream()),
+                    ));
+                }
+            }
+        };
+
+        let impl_generics = if input.peek(Lt) {
+            input.parse()?
+        } else {
+            Default::default()
+        };
+
+        let context_type: Type = input.parse()?;
+
+        let trait_name = if let Some(check_trait_name) = m_check_trait_name {
+            check_trait_name
+        } else {
+            let context_type: IdentWithTypeArgs = parse2(context_type.to_token_stream())?;
+
+            Ident::new(
+                &format!("__Check{}", context_type.ident),
+                context_type.span(),
+            )
+        };
+
+        let where_clause = if input.peek(Where) {
+            input.parse()?
+        } else {
+            WhereClause {
+                where_token: Where(Span::call_site()),
+                predicates: Punctuated::default(),
+            }
+        };
+
+        let content;
+        braced!(content in input);
+
+        let entries: CheckEntries = content.parse()?;
+
+        Ok(Self {
+            check_providers,
+            impl_generics,
+            trait_name,
+            context_type,
+            where_clause,
+            check_entries: entries,
+        })
+    }
+}
+
+fn override_span<T>(span: &Span, body: &T) -> syn::Result<T>
+where
+    T: Parse + ToTokens,
+{
+    parse2(
+        body.to_token_stream()
+            .into_iter()
+            .map(|mut tree| {
+                tree.set_span(*span);
+                tree
+            })
+            .collect(),
+    )
+}