feat(protocol): reference-based DiagnosticReport!

README.md

@@ -50,7 +50,6 @@ You can derive a Diagnostic from any `std::error::Error` type.
 
 `thiserror` is a great way to define them so, and plays extremely nicely with `miette`!
 */
-use std::sync::Arc;
 use miette::Diagnostic;
 use thiserror::Error;
 
@@ -62,7 +61,7 @@ use thiserror::Error;
     help("try doing it better next time?"),
 )]
 struct MyBad {
-    src: Arc<String>,
+    src: String,
     // Snippets and highlights can be included in the diagnostic!
     #[snippet(src, "This is the part that broke")]
     snip: SourceSpan,
@@ -101,7 +100,7 @@ fn pretend_this_is_main() -> Result<(), MyBad> {
     let len = src.len();
 
     Err(MyBad {
-        src: Arc::new(src),
+        src,
         snip: ("bad_file.rs", 0, len).into(),
         bad_bit: ("this bit here", 9, 3).into(),
     })

miette-derive/src/snippets.rs

@@ -176,12 +176,12 @@ impl Snippets {
                 .map(|msg| match msg {
                     MemberOrString::String(str) => {
                         quote! {
-                            message: std::option::Option::Some(#str.into()),
+                            message: std::option::Option::Some(#str),
                         }
                     }
                     MemberOrString::Member(m) => {
                         quote! {
-                            message: std::option::Option::Some(self.#m.clone()),
+                            message: std::option::Option::Some(self.#m.as_ref()),
                         }
                     }
                 })
@@ -194,21 +194,20 @@ impl Snippets {
             // Source field
             let src_ident = &snippet.source;
             let src_ident = quote! {
-                // TODO: I don't like this. Think about it more and maybe improve protocol?
-                source: self.#src_ident.clone(),
+                source: &self.#src_ident,
             };
 
             // Context
             let context = &snippet.snippet;
             let context = quote! {
-                context: self.#context.clone(),
+                context: &self.#context,
             };
 
             // Highlights
             let highlights = snippet.highlights.iter().map(|highlight| {
                 let Highlight { highlight } = highlight;
                 quote! {
-                    self.#highlight.clone()
+                    &self.#highlight
                 }
             });
             let highlights = quote! {
@@ -229,7 +228,7 @@ impl Snippets {
         });
         Some(quote! {
             #[allow(unused_variables)]
-            fn snippets(&self) -> std::option::Option<std::boxed::Box<dyn std::iter::Iterator<Item = miette::DiagnosticSnippet>>> {
+            fn snippets(&self) -> std::option::Option<std::boxed::Box<dyn std::iter::Iterator<Item = miette::DiagnosticSnippet> + '_>> {
                 Some(Box::new(vec![
                     #(#snippets),*
                 ].into_iter()))
@@ -248,7 +247,7 @@ impl Snippets {
                         .map(|msg| match msg {
                             MemberOrString::String(str) => {
                                 quote! {
-                                    message: std::option::Option::Some(#str.into()),
+                                    message: std::option::Option::Some(#str),
                                 }
                             }
                             MemberOrString::Member(m) => {
@@ -259,7 +258,7 @@ impl Snippets {
                                     }
                                 };
                                 quote! {
-                                    message: std::option::Option::Some(#m.clone()),
+                                    message: std::option::Option::Some(#m.as_ref()),
                                 }
                             }
                         })
@@ -278,7 +277,7 @@ impl Snippets {
                     };
                     let src_ident = quote! {
                         // TODO: I don't like this. Think about it more and maybe improve protocol?
-                        source: #src_ident.clone(),
+                        source: #src_ident,
                     };
 
                     // Context
@@ -289,7 +288,7 @@ impl Snippets {
                         }
                     };
                     let context = quote! {
-                        context: #context.clone(),
+                        context: #context,
                     };
 
                     // Highlights
@@ -302,7 +301,7 @@ impl Snippets {
                             }
                         };
                         quote! {
-                            #m.clone()
+                            #m
                         }
                     });
                     let highlights = quote! {
@@ -346,7 +345,7 @@ impl Snippets {
         });
         Some(quote! {
             #[allow(unused_variables)]
-            fn snippets(&self) -> std::option::Option<std::boxed::Box<dyn std::iter::Iterator<Item = miette::DiagnosticSnippet>>> {
+            fn snippets(&self) -> std::option::Option<std::boxed::Box<dyn std::iter::Iterator<Item = miette::DiagnosticSnippet> + '_>> {
                 match self {
                     #(#variant_arms)*
                     _ => std::option::Option::None,

src/protocol.rs

@@ -4,7 +4,7 @@ that you can implement to get access to miette's (and related library's) full
 reporting and such features.
 */
 
-use std::{fmt::Display, sync::Arc};
+use std::fmt::Display;
 
 use crate::MietteError;
 
@@ -36,7 +36,7 @@ pub trait Diagnostic: std::error::Error {
 
     /// Additional contextual snippets. This is typically used for adding
     /// marked-up source file output the way compilers often do.
-    fn snippets(&self) -> Option<Box<dyn Iterator<Item = DiagnosticSnippet>>> {
+    fn snippets(&self) -> Option<Box<dyn Iterator<Item = DiagnosticSnippet> + '_>> {
         None
     }
 }
@@ -171,17 +171,17 @@ impl<'a> SpanContents for MietteSpanContents<'a> {
 A snippet from a [Source] to be displayed with a message and possibly some highlights.
  */
 #[derive(Clone, Debug)]
-pub struct DiagnosticSnippet {
+pub struct DiagnosticSnippet<'a> {
     /// Explanation of this specific diagnostic snippet.
-    pub message: Option<String>,
+    pub message: Option<&'a str>,
     /// A [Source] that can be used to read the actual text of a source.
-    pub source: Arc<dyn Source>,
+    pub source: &'a (dyn Source),
     /// The primary [SourceSpan] where this diagnostic is located.
-    pub context: SourceSpan,
+    pub context: &'a SourceSpan,
     /// Additional [SourceSpan]s that mark specific sections of the span, for
     /// example, to underline specific text within the larger span. They're
     /// paired with labels that should be applied to those sections.
-    pub highlights: Option<Vec<SourceSpan>>,
+    pub highlights: Option<Vec<&'a SourceSpan>>,
 }
 
 /**

src/reporter.rs

@@ -33,7 +33,7 @@ impl MietteReporter {
         writeln!(f)?;
         let context_data = snippet
             .source
-            .read_span(&snippet.context)
+            .read_span(snippet.context)
             .map_err(|_| fmt::Error)?;
         let context = std::str::from_utf8(context_data.data()).expect("Bad utf8 detected");
         let mut line = context_data.line();
@@ -180,7 +180,8 @@ impl DiagnosticReporter for JokeReporter {
             "miette, her eyes enormous: you {} miette? you {}? oh! oh! jail for mother! jail for mother for One Thousand Years!!!!",
             diagnostic.code(),
             diagnostic.snippets().map(|snippets| {
-                snippets.map(|snippet| snippet.message).collect::<Option<Vec<String>>>()
+                snippets.map(|snippet| snippet.message.map(|x| x.to_owned()))
+                .collect::<Option<Vec<String>>>()
             }).flatten().map(|x| x.join(", ")).unwrap_or_else(||"try and cause miette to panic".into())
         )?;
 

tests/derive.rs

@@ -1,5 +1,3 @@
-use std::sync::Arc;
-
 use miette::{Diagnostic, Severity, SourceSpan};
 use thiserror::Error;
 
@@ -166,11 +164,9 @@ fn test_snippet_named_struct() {
     #[diagnostic(code(foo::bar::baz))]
     struct Foo {
         // The actual "source code" our contexts will be using. This can be
-        // reused by multiple contexts!
-        //
-        // The `Arc` is so you don't have to clone the entire thing into this
-        // Diagnostic. We just need to be able to read it~
-        src: Arc<String>,
+        // reused by multiple contexts, and just needs to implement
+        // miette::Source!
+        src: String,
 
         // The "snippet" span. This is the span that will be displayed to
         // users. It should be a big enough slice of the Source to provide
@@ -215,7 +211,7 @@ fn test_snippet_unnamed_struct() {
     #[error("welp")]
     #[diagnostic(code(foo::bar::baz))]
     struct Foo(
-        Arc<String>,
+        String,
         #[snippet(0, "hi")] SourceSpan,
         #[highlight(1)] SourceSpan,
         #[highlight(1)] SourceSpan,
@@ -235,7 +231,7 @@ fn test_snippet_enum() {
     enum Foo {
         #[diagnostic(code(foo::a))]
         A {
-            src: Arc<String>,
+            src: String,
             #[snippet(src, "my_snippet.rs", "hi this is where the thing went wrong")]
             snip: SourceSpan,
             #[highlight(snip, "var 1")]
@@ -249,7 +245,7 @@ fn test_snippet_enum() {
         },
         #[diagnostic(code(foo::b))]
         B(
-            Arc<String>,
+            String,
             #[snippet(0, "my_snippet.rs", "hi")] SourceSpan,
             #[highlight(1, "var 1")] SourceSpan,
             #[highlight(1, "var 2")] SourceSpan,

tests/reporter.rs

@@ -1,12 +1,17 @@
-use std::{fmt, sync::Arc};
+use std::fmt;
 
-use miette::{Diagnostic, DiagnosticReporter, DiagnosticSnippet, MietteError, MietteReporter};
+use miette::{
+    Diagnostic, DiagnosticReporter, DiagnosticSnippet, MietteError, MietteReporter, SourceSpan,
+};
 use thiserror::Error;
 
 #[derive(Error)]
 #[error("oops!")]
 struct MyBad {
-    snippets: Vec<DiagnosticSnippet>,
+    message: String,
+    src: String,
+    ctx: SourceSpan,
+    highlight: SourceSpan,
 }
 
 impl fmt::Debug for MyBad {
@@ -24,35 +29,28 @@ impl Diagnostic for MyBad {
         Some(Box::new(&"try doing it better next time?"))
     }
 
-    fn snippets(&self) -> Option<Box<dyn Iterator<Item = DiagnosticSnippet>>> {
-        Some(Box::new(self.snippets.clone().into_iter()))
+    fn snippets(&self) -> Option<Box<dyn Iterator<Item = DiagnosticSnippet> + '_>> {
+        Some(Box::new(
+            vec![DiagnosticSnippet {
+                message: Some(self.message.as_ref()),
+                source: &self.src,
+                context: &self.ctx,
+                highlights: Some(vec![&self.highlight]),
+            }]
+            .into_iter(),
+        ))
     }
 }
 
-#[test]
-fn basic() -> Result<(), MietteError> {
-    let err = MyBad {
-        snippets: Vec::new(),
-    };
-    let out = format!("{:?}", err);
-    assert_eq!(
-        "Error[oops::my::bad]: oops!\n\n﹦try doing it better next time?\n".to_string(),
-        out
-    );
-    Ok(())
-}
-
 #[test]
 fn fancy() -> Result<(), MietteError> {
     let src = "source\n  text\n    here".to_string();
     let len = src.len();
     let err = MyBad {
-        snippets: vec![DiagnosticSnippet {
-            message: Some("This is the part that broke".into()),
-            source: Arc::new(src),
-            highlights: Some(vec![("this bit here", 9, 4).into()]),
-            context: ("bad_file.rs", 0, len).into(),
-        }],
+        message: "This is the part that broke".into(),
+        src,
+        ctx: ("bad_file.rs", 0, len).into(),
+        highlight: ("this bit here", 9, 4).into(),
     };
     let out = format!("{:?}", err);
     // println!("{}", out);