meta: initial commit (archival)

src/lib.rs

@@ -0,0 +1,50 @@
+use std::{
+    error::Error,
+    fmt::{Debug, Display, Formatter},
+};
+
+#[derive(Debug)]
+pub struct ErrorWithSuggestion<E, S> {
+    error: E,
+    suggestion: S,
+}
+
+impl<E: Display, S: Display> Display for ErrorWithSuggestion<E, S> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        self.error.fmt(f)?;
+        writeln!(f)?;
+
+        write!(f, "💡 ")?;
+        self.suggestion.fmt(f)?;
+
+        Ok(())
+    }
+}
+
+impl<E: Error, S: Debug + Display> Error for ErrorWithSuggestion<E, S> {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        self.error.source()
+    }
+}
+
+pub trait ResultExt {
+    type O;
+    type E;
+
+    fn with_suggestion<Suggestion: Display>(
+        self,
+        suggestion: Suggestion,
+    ) -> Result<Self::O, ErrorWithSuggestion<Self::E, Suggestion>>;
+}
+
+impl<Ok, Err> ResultExt for Result<Ok, Err> {
+    type O = Ok;
+    type E = Err;
+
+    fn with_suggestion<Suggestion: Display>(
+        self,
+        suggestion: Suggestion,
+    ) -> Result<Self::O, ErrorWithSuggestion<Self::E, Suggestion>> {
+        self.map_err(|error| ErrorWithSuggestion { error, suggestion })
+    }
+}