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-rw-r--r--src/parse_trait_sig.rs169
1 files changed, 15 insertions, 154 deletions
diff --git a/src/parse_trait_sig.rs b/src/parse_trait_sig.rs
index 55a3214..0078c93 100644
--- a/src/parse_trait_sig.rs
+++ b/src/parse_trait_sig.rs
@@ -1,14 +1,12 @@
-use std::collections::HashMap;
-
use proc_macro2::Span;
use syn::{
- spanned::Spanned, FnArg, Ident, PathArguments, PredicateType, Receiver, ReturnType, Type,
- TypePath, WherePredicate,
+ spanned::Spanned, FnArg, PredicateType, Receiver, ReturnType, Type, TypePath, WherePredicate,
};
-use syn::{GenericParam, Signature, TypeImplTrait, TypeParamBound};
+use syn::{Signature, TypeImplTrait};
-use crate::syn_utils::{find_in_path, find_in_type, trait_bounds, TypeMatcher};
-use crate::{As, AssocTypeMatcher};
+use crate::syn_utils::{find_in_type, trait_bounds, TypeMatcher};
+use crate::transform::{dynamize_function_bounds, AssocTypeConversions, TransformError};
+use crate::AssocTypeMatcher;
#[derive(Debug, Clone)]
pub enum TypeTransform {
@@ -47,10 +45,8 @@ pub struct SignatureChanges {
pub fn parse_trait_signature(
signature: &mut Signature,
- assoc_type_conversions: &HashMap<&Ident, &Type>,
+ assoc_type_conversions: &AssocTypeConversions,
) -> Result<SignatureChanges, (Span, MethodParseError)> {
- let assoc_type_conversions = AssocTypeConversions(assoc_type_conversions);
-
if is_non_dispatchable(signature) {
return Err((signature.span(), MethodParseError::NonDispatchableMethod));
}
@@ -67,58 +63,10 @@ pub fn parse_trait_signature(
}
}
- let mut type_param_transforms = HashMap::new();
+ let type_param_transforms =
+ dynamize_function_bounds(&mut signature.generics, assoc_type_conversions)?;
let mut input_transforms = Vec::new();
- for generic_param in &mut signature.generics.params {
- if let GenericParam::Type(type_param) = generic_param {
- for bound in &mut type_param.bounds {
- if let TypeParamBound::Trait(bound) = bound {
- if bound.path.segments.len() == 1 {
- let segment = bound.path.segments.first_mut().unwrap();
-
- if let PathArguments::Parenthesized(args) = &mut segment.arguments {
- if segment.ident == "Fn"
- || segment.ident == "FnOnce"
- || segment.ident == "FnMut"
- {
- let mut transforms = Vec::new();
- for input_type in &mut args.inputs {
- match assoc_type_conversions.parse_type_path(input_type) {
- Ok(ret_type) => {
- transforms.push(ret_type);
- }
- Err(TransformError::UnconvertibleAssocType(span)) => {
- return Err((
- span,
- MethodParseError::UnconvertibleAssocType,
- ));
- }
- Err(TransformError::AssocTypeInUnsupportedType(span)) => {
- return Err((
- span,
- MethodParseError::UnconvertibleAssocTypeInFnInput,
- ));
- }
- }
- }
- if transforms.iter().any(|t| !matches!(t, TypeTransform::NoOp)) {
- type_param_transforms.insert(&type_param.ident, transforms);
- }
- }
- }
- }
- if let Some(path) = find_in_path(&bound.path, &AssocTypeMatcher) {
- return Err((
- path.span(),
- MethodParseError::UnconvertibleAssocTypeInTraitBound,
- ));
- }
- }
- }
- }
- }
-
for input in &signature.inputs {
if let FnArg::Typed(pattype) = input {
if let Type::Path(path) = &*pattype.ty {
@@ -149,94 +97,6 @@ pub fn parse_trait_signature(
})
}
-struct AssocTypeConversions<'a>(&'a HashMap<&'a Ident, &'a Type>);
-
-enum TransformError {
- UnconvertibleAssocType(Span),
- AssocTypeInUnsupportedType(Span),
-}
-
-impl AssocTypeConversions<'_> {
- fn parse_type_path(&self, type_: &mut Type) -> Result<TypeTransform, TransformError> {
- let assoc_span = match find_in_type(type_, &AssocTypeMatcher) {
- Some(path) => path.span(),
- None => return Ok(TypeTransform::NoOp),
- };
-
- if let Type::Path(TypePath { path, qself: None }) = type_ {
- let ident = &path.segments.first().unwrap().ident;
-
- // TODO: support &mut dyn Iterator<Item = Self::A>
- // conversion to Box<dyn Iterator<Item = Whatever>> via .map(Into::into)
-
- if ident == "Self" && path.segments.len() == 2 {
- let ident = &path.segments.last().unwrap().ident;
- *type_ = (*self
- .0
- .get(&ident)
- .ok_or_else(|| TransformError::UnconvertibleAssocType(ident.span()))?)
- .clone();
- return Ok(TypeTransform::Into);
- } else if ident == "Option" && path.segments.len() == 1 {
- let first_seg = path.segments.first_mut().unwrap();
-
- if let Some(args) = first_seg.arguments.get_as_mut() {
- if args.args.len() == 1 {
- if let Some(generic_type) = args.args.first_mut().unwrap().get_as_mut() {
- if find_in_type(generic_type, &AssocTypeMatcher).is_some() {
- return Ok(TypeTransform::Map(
- self.parse_type_path(generic_type)?.into(),
- ));
- }
- }
- }
- }
- } else if ident == "Result" && path.segments.len() == 1 {
- let first_seg = path.segments.first_mut().unwrap();
- if let Some(args) = first_seg.arguments.get_as_mut() {
- if args.args.len() == 2 {
- let mut args_iter = args.args.iter_mut();
- if let (Some(ok_type), Some(err_type)) = (
- args_iter.next().unwrap().get_as_mut(),
- args_iter.next().unwrap().get_as_mut(),
- ) {
- if find_in_type(ok_type, &AssocTypeMatcher).is_some()
- || find_in_type(err_type, &AssocTypeMatcher).is_some()
- {
- return Ok(TypeTransform::Result(
- self.parse_type_path(ok_type)?.into(),
- self.parse_type_path(err_type)?.into(),
- ));
- }
- }
- }
- }
- } else {
- let last_seg = &path.segments.last().unwrap();
- if last_seg.ident == "Result" {
- let last_seg = path.segments.last_mut().unwrap();
- if let Some(args) = last_seg.arguments.get_as_mut() {
- if args.args.len() == 1 {
- if let Some(generic_type) = args.args.first_mut().unwrap().get_as_mut()
- {
- if find_in_type(generic_type, &AssocTypeMatcher).is_some() {
- return Ok(TypeTransform::Map(
- self.parse_type_path(generic_type)?.into(),
- ));
- }
- }
- }
- }
- }
- }
- }
-
- // the type contains an associated type but we
- // don't know how to deal with it so we abort
- Err(TransformError::AssocTypeInUnsupportedType(assoc_span))
- }
-}
-
fn is_non_dispatchable(signature: &Signature) -> bool {
// non-dispatchable: fn example(&self) where Self: Sized;
if let Some(where_clause) = &signature.generics.where_clause {
@@ -288,13 +148,14 @@ fn bounds_self_and_has_bound_sized(predicate: &WherePredicate) -> bool {
#[cfg(test)]
mod tests {
- use std::collections::HashMap;
-
use quote::{format_ident, quote};
use syn::{TraitItemMethod, Type};
- use crate::parse_trait_sig::{
- parse_trait_signature, MethodParseError, SignatureChanges, TypeTransform,
+ use crate::{
+ parse_trait_sig::{
+ parse_trait_signature, MethodParseError, SignatureChanges, TypeTransform,
+ },
+ transform::AssocTypeConversions,
};
#[test]
@@ -320,10 +181,10 @@ mod tests {
})
.unwrap();
- let mut assoc_type_map = HashMap::new();
+ let mut assoc_type_map = AssocTypeConversions::default();
let ident = format_ident!("A");
let dest = Type::Verbatim(quote! {Example});
- assoc_type_map.insert(&ident, &dest);
+ assoc_type_map.0.insert(&ident, &dest);
assert!(matches!(
parse_trait_signature(&mut type1.sig, &assoc_type_map),
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-02 16:36:06 +0000