diff options
Diffstat (limited to 'third_party/rust/clap_derive/src/utils/spanned.rs')
-rw-r--r-- | third_party/rust/clap_derive/src/utils/spanned.rs | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/third_party/rust/clap_derive/src/utils/spanned.rs b/third_party/rust/clap_derive/src/utils/spanned.rs new file mode 100644 index 0000000000..11415f6f0e --- /dev/null +++ b/third_party/rust/clap_derive/src/utils/spanned.rs @@ -0,0 +1,92 @@ +use proc_macro2::{Ident, Span, TokenStream}; +use quote::ToTokens; +use syn::LitStr; + +use std::ops::{Deref, DerefMut}; + +/// An entity with a span attached. +#[derive(Debug, Clone)] +pub struct Sp<T> { + val: T, + span: Span, +} + +impl<T> Sp<T> { + pub fn new(val: T, span: Span) -> Self { + Sp { val, span } + } + + pub fn call_site(val: T) -> Self { + Sp { + val, + span: Span::call_site(), + } + } + + pub fn span(&self) -> Span { + self.span + } +} + +impl<T> Deref for Sp<T> { + type Target = T; + + fn deref(&self) -> &T { + &self.val + } +} + +impl<T> DerefMut for Sp<T> { + fn deref_mut(&mut self) -> &mut T { + &mut self.val + } +} + +impl From<Ident> for Sp<String> { + fn from(ident: Ident) -> Self { + Sp { + val: ident.to_string(), + span: ident.span(), + } + } +} + +impl From<LitStr> for Sp<String> { + fn from(lit: LitStr) -> Self { + Sp { + val: lit.value(), + span: lit.span(), + } + } +} + +impl<'a> From<Sp<&'a str>> for Sp<String> { + fn from(sp: Sp<&'a str>) -> Self { + Sp::new(sp.val.into(), sp.span) + } +} + +impl<U, T: PartialEq<U>> PartialEq<U> for Sp<T> { + fn eq(&self, other: &U) -> bool { + self.val == *other + } +} + +impl<T: AsRef<str>> AsRef<str> for Sp<T> { + fn as_ref(&self) -> &str { + self.val.as_ref() + } +} + +impl<T: ToTokens> ToTokens for Sp<T> { + fn to_tokens(&self, stream: &mut TokenStream) { + // this is the simplest way out of correct ones to change span on + // arbitrary token tree I could come up with + let tt = self.val.to_token_stream().into_iter().map(|mut tt| { + tt.set_span(self.span); + tt + }); + + stream.extend(tt); + } +} |