Merge commit '6eba9cd92c295c5389944f6adda1f1e83b2cb008' as 'subprojects/thiserror'

subprojects/thiserror/impl/src/unraw.rs

@@ -0,0 +1,142 @@
+use proc_macro2::{Ident, Span, TokenStream};
+use quote::ToTokens;
+use std::cmp::Ordering;
+use std::fmt::{self, Display};
+use std::hash::{Hash, Hasher};
+use syn::ext::IdentExt as _;
+use syn::parse::{Parse, ParseStream, Result};
+use syn::Index;
+
+#[derive(Clone)]
+#[repr(transparent)]
+pub struct IdentUnraw(Ident);
+
+impl IdentUnraw {
+    pub fn new(ident: Ident) -> Self {
+        IdentUnraw(ident)
+    }
+
+    pub fn to_local(&self) -> Ident {
+        let unraw = self.0.unraw();
+        let repr = unraw.to_string();
+        if syn::parse_str::<Ident>(&repr).is_err() {
+            if let "_" | "super" | "self" | "Self" | "crate" = repr.as_str() {
+                // Some identifiers are never allowed to appear as raw, like r#self and r#_.
+            } else {
+                return Ident::new_raw(&repr, Span::call_site());
+            }
+        }
+        unraw
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.0.set_span(span);
+    }
+}
+
+impl Display for IdentUnraw {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.0.unraw(), formatter)
+    }
+}
+
+impl Eq for IdentUnraw {}
+
+impl PartialEq for IdentUnraw {
+    fn eq(&self, other: &Self) -> bool {
+        PartialEq::eq(&self.0.unraw(), &other.0.unraw())
+    }
+}
+
+impl PartialEq<str> for IdentUnraw {
+    fn eq(&self, other: &str) -> bool {
+        self.0 == other
+    }
+}
+
+impl Ord for IdentUnraw {
+    fn cmp(&self, other: &Self) -> Ordering {
+        Ord::cmp(&self.0.unraw(), &other.0.unraw())
+    }
+}
+
+impl PartialOrd for IdentUnraw {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(Self::cmp(self, other))
+    }
+}
+
+impl Parse for IdentUnraw {
+    fn parse(input: ParseStream) -> Result<Self> {
+        input.call(Ident::parse_any).map(IdentUnraw::new)
+    }
+}
+
+impl ToTokens for IdentUnraw {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        self.0.unraw().to_tokens(tokens);
+    }
+}
+
+#[derive(Clone)]
+pub enum MemberUnraw {
+    Named(IdentUnraw),
+    Unnamed(Index),
+}
+
+impl MemberUnraw {
+    pub fn span(&self) -> Span {
+        match self {
+            MemberUnraw::Named(ident) => ident.0.span(),
+            MemberUnraw::Unnamed(index) => index.span,
+        }
+    }
+}
+
+impl Display for MemberUnraw {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            MemberUnraw::Named(this) => Display::fmt(this, formatter),
+            MemberUnraw::Unnamed(this) => Display::fmt(&this.index, formatter),
+        }
+    }
+}
+
+impl Eq for MemberUnraw {}
+
+impl PartialEq for MemberUnraw {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (MemberUnraw::Named(this), MemberUnraw::Named(other)) => this == other,
+            (MemberUnraw::Unnamed(this), MemberUnraw::Unnamed(other)) => this == other,
+            _ => false,
+        }
+    }
+}
+
+impl PartialEq<str> for MemberUnraw {
+    fn eq(&self, other: &str) -> bool {
+        match self {
+            MemberUnraw::Named(this) => this == other,
+            MemberUnraw::Unnamed(_) => false,
+        }
+    }
+}
+
+impl Hash for MemberUnraw {
+    fn hash<H: Hasher>(&self, hasher: &mut H) {
+        match self {
+            MemberUnraw::Named(ident) => ident.0.unraw().hash(hasher),
+            MemberUnraw::Unnamed(index) => index.hash(hasher),
+        }
+    }
+}
+
+impl ToTokens for MemberUnraw {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        match self {
+            MemberUnraw::Named(ident) => ident.to_local().to_tokens(tokens),
+            MemberUnraw::Unnamed(index) => index.to_tokens(tokens),
+        }
+    }
+}