syntax/instantiate.rs

use crate::syntax::{NamedType, Type};
use proc_macro2::Ident;
use std::hash::{Hash, Hasher};
use syn::Token;

#[derive(Copy, Clone, PartialEq, Eq, Hash)]
pub enum ImplKey<'a> {
    RustBox(NamedImplKey<'a>),
    RustVec(NamedImplKey<'a>),
    UniquePtr(NamedImplKey<'a>),
    SharedPtr(NamedImplKey<'a>),
    WeakPtr(NamedImplKey<'a>),
    CxxVector(NamedImplKey<'a>),
}

#[derive(Copy, Clone)]
pub struct NamedImplKey<'a> {
    pub rust: &'a Ident,
    pub lt_token: Option<Token![<]>,
    pub gt_token: Option<Token![>]>,
}

impl Type {
    pub(crate) fn impl_key(&self) -> Option<ImplKey> {
        if let Type::RustBox(ty) = self {
            if let Type::Ident(ident) = &ty.inner {
                return Some(ImplKey::RustBox(NamedImplKey::from(ident)));
            }
        } else if let Type::RustVec(ty) = self {
            if let Type::Ident(ident) = &ty.inner {
                return Some(ImplKey::RustVec(NamedImplKey::from(ident)));
            }
        } else if let Type::UniquePtr(ty) = self {
            if let Type::Ident(ident) = &ty.inner {
                return Some(ImplKey::UniquePtr(NamedImplKey::from(ident)));
            }
        } else if let Type::SharedPtr(ty) = self {
            if let Type::Ident(ident) = &ty.inner {
                return Some(ImplKey::SharedPtr(NamedImplKey::from(ident)));
            }
        } else if let Type::WeakPtr(ty) = self {
            if let Type::Ident(ident) = &ty.inner {
                return Some(ImplKey::WeakPtr(NamedImplKey::from(ident)));
            }
        } else if let Type::CxxVector(ty) = self {
            if let Type::Ident(ident) = &ty.inner {
                return Some(ImplKey::CxxVector(NamedImplKey::from(ident)));
            }
        }
        None
    }
}

impl<'a> PartialEq for NamedImplKey<'a> {
    fn eq(&self, other: &Self) -> bool {
        PartialEq::eq(self.rust, other.rust)
    }
}

impl<'a> Eq for NamedImplKey<'a> {}

impl<'a> Hash for NamedImplKey<'a> {
    fn hash<H: Hasher>(&self, hasher: &mut H) {
        self.rust.hash(hasher);
    }
}

impl<'a> From<&'a NamedType> for NamedImplKey<'a> {
    fn from(ty: &'a NamedType) -> Self {
        NamedImplKey {
            rust: &ty.rust,
            lt_token: ty.generics.lt_token,
            gt_token: ty.generics.gt_token,
        }
    }
}