1 files changed, 161 insertions, 0 deletions
diff --git a/vendor/miette-derive/src/forward.rs b/vendor/miette-derive/src/forward.rs
new file mode 100644
index 0000000..171019a
--- /dev/null
+++ b/vendor/miette-derive/src/forward.rs
@@ -0,0 +1,161 @@
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote};
+use syn::{
+    parenthesized,
+    parse::{Parse, ParseStream},
+    spanned::Spanned,
+};
+
+pub enum Forward {
+    Unnamed(usize),
+    Named(syn::Ident),
+}
+
+impl Parse for Forward {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let forward = input.parse::<syn::Ident>()?;
+        if forward != "forward" {
+            return Err(syn::Error::new(forward.span(), "msg"));
+        }
+        let content;
+        parenthesized!(content in input);
+        let looky = content.lookahead1();
+        if looky.peek(syn::LitInt) {
+            let int: syn::LitInt = content.parse()?;
+            let index = int.base10_parse()?;
+            return Ok(Forward::Unnamed(index));
+        }
+        Ok(Forward::Named(content.parse()?))
+    }
+}
+
+#[derive(Copy, Clone)]
+pub enum WhichFn {
+    Code,
+    Help,
+    Url,
+    Severity,
+    Labels,
+    SourceCode,
+    Related,
+    DiagnosticSource,
+}
+
+impl WhichFn {
+    pub fn method_call(&self) -> TokenStream {
+        match self {
+            Self::Code => quote! { code() },
+            Self::Help => quote! { help() },
+            Self::Url => quote! { url() },
+            Self::Severity => quote! { severity() },
+            Self::Labels => quote! { labels() },
+            Self::SourceCode => quote! { source_code() },
+            Self::Related => quote! { related() },
+            Self::DiagnosticSource => quote! { diagnostic_source() },
+        }
+    }
+
+    pub fn signature(&self) -> TokenStream {
+        match self {
+            Self::Code => quote! {
+                fn code(& self) -> std::option::Option<std::boxed::Box<dyn std::fmt::Display + '_>>
+            },
+            Self::Help => quote! {
+                fn help(& self) -> std::option::Option<std::boxed::Box<dyn std::fmt::Display + '_>>
+            },
+            Self::Url => quote! {
+                fn url(& self) -> std::option::Option<std::boxed::Box<dyn std::fmt::Display + '_>>
+            },
+            Self::Severity => quote! {
+                fn severity(&self) -> std::option::Option<miette::Severity>
+            },
+            Self::Related => quote! {
+                fn related(&self) -> std::option::Option<std::boxed::Box<dyn std::iter::Iterator<Item = &dyn miette::Diagnostic> + '_>>
+            },
+            Self::Labels => quote! {
+                fn labels(&self) -> std::option::Option<std::boxed::Box<dyn std::iter::Iterator<Item = miette::LabeledSpan> + '_>>
+            },
+            Self::SourceCode => quote! {
+                fn source_code(&self) -> std::option::Option<&dyn miette::SourceCode>
+            },
+            Self::DiagnosticSource => quote! {
+                fn diagnostic_source(&self) -> std::option::Option<&dyn miette::Diagnostic>
+            },
+        }
+    }
+
+    pub fn catchall_arm(&self) -> TokenStream {
+        quote! { _ => std::option::Option::None }
+    }
+}
+
+impl Forward {
+    pub fn for_transparent_field(fields: &syn::Fields) -> syn::Result<Self> {
+        let make_err = || {
+            syn::Error::new(
+                fields.span(),
+                "you can only use #[diagnostic(transparent)] with exactly one field",
+            )
+        };
+        match fields {
+            syn::Fields::Named(named) => {
+                let mut iter = named.named.iter();
+                let field = iter.next().ok_or_else(make_err)?;
+                if iter.next().is_some() {
+                    return Err(make_err());
+                }
+                let field_name = field
+                    .ident
+                    .clone()
+                    .unwrap_or_else(|| format_ident!("unnamed"));
+                Ok(Self::Named(field_name))
+            }
+            syn::Fields::Unnamed(unnamed) => {
+                if unnamed.unnamed.iter().len() != 1 {
+                    return Err(make_err());
+                }
+                Ok(Self::Unnamed(0))
+            }
+            _ => Err(syn::Error::new(
+                fields.span(),
+                "you cannot use #[diagnostic(transparent)] with a unit struct or a unit variant",
+            )),
+        }
+    }
+
+    pub fn gen_struct_method(&self, which_fn: WhichFn) -> TokenStream {
+        let signature = which_fn.signature();
+        let method_call = which_fn.method_call();
+
+        let field_name = match self {
+            Forward::Named(field_name) => quote!(#field_name),
+            Forward::Unnamed(index) => {
+                let index = syn::Index::from(*index);
+                quote!(#index)
+            }
+        };
+
+        quote! {
+            #[inline]
+            #signature {
+                self.#field_name.#method_call
+            }
+        }
+    }
+
+    pub fn gen_enum_match_arm(&self, variant: &syn::Ident, which_fn: WhichFn) -> TokenStream {
+        let method_call = which_fn.method_call();
+        match self {
+            Forward::Named(field_name) => quote! {
+                Self::#variant { #field_name, .. } => #field_name.#method_call,
+            },
+            Forward::Unnamed(index) => {
+                let underscores: Vec<_> = core::iter::repeat(quote! { _, }).take(*index).collect();
+                let unnamed = format_ident!("unnamed");
+                quote! {
+                    Self::#variant ( #(#underscores)* #unnamed, .. ) => #unnamed.#method_call,
+                }
+            }
+        }
+    }
+}