From a823ae781133b523cd05994fc7a459289d5efc75 Mon Sep 17 00:00:00 2001
From: Connor Skees <connor1skees@gmail.com>
Date: Sat, 4 Jul 2020 11:27:57 -0400
Subject: [PATCH] remove fallible trait impls from `SassError`

---
 src/args.rs              |  2 +-
 src/error.rs             | 58 +++++-----------------------------------
 src/parse/value/eval.rs  |  2 +-
 src/parse/value/parse.rs |  4 +--
 4 files changed, 11 insertions(+), 55 deletions(-)

diff --git a/src/args.rs b/src/args.rs
index db6df85..6f32a98 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -35,7 +35,7 @@ impl FuncArgs {
     }
 }
 
-#[derive(Debug, Clone, Eq, PartialEq)]
+#[derive(Debug, Clone)]
 pub(crate) struct CallArgs(pub HashMap<CallArg, SassResult<Spanned<Value>>>, pub Span);
 
 #[derive(Debug, Clone, Hash, Eq, PartialEq)]
diff --git a/src/error.rs b/src/error.rs
index 93a3dcf..108de6b 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -2,6 +2,7 @@ use std::{
     error::Error,
     fmt::{self, Display},
     io,
+    rc::Rc,
     string::FromUtf8Error,
 };
 
@@ -9,58 +10,11 @@ use codemap::{Span, SpanLoc};
 
 pub type SassResult<T> = Result<T, Box<SassError>>;
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct SassError {
     kind: SassErrorKind,
 }
 
-// todo: we should split the unclonable errors (io, potentially others) into
-// a separate enum to allow these methods to be infallible
-#[allow(clippy::unimplemented)]
-impl Clone for SassError {
-    #[inline]
-    fn clone(&self) -> Self {
-        match &self.kind {
-            SassErrorKind::Raw(a, b) => SassError {
-                kind: SassErrorKind::Raw(a.clone(), *b),
-            },
-            SassErrorKind::ParseError { message, loc } => SassError {
-                kind: SassErrorKind::ParseError {
-                    message: message.clone(),
-                    loc: loc.clone(),
-                },
-            },
-            _ => unimplemented!(),
-        }
-    }
-}
-
-#[allow(clippy::unimplemented)]
-impl PartialEq for SassError {
-    #[inline]
-    fn eq(&self, other: &Self) -> bool {
-        match &self.kind {
-            SassErrorKind::Raw(a, b) => match &other.kind {
-                SassErrorKind::Raw(c, d) => a == c && b == d,
-                _ => false,
-            },
-            SassErrorKind::ParseError {
-                message: message1,
-                loc: loc1,
-            } => match &other.kind {
-                SassErrorKind::ParseError {
-                    message: message2,
-                    loc: loc2,
-                } => message1 == message2 && loc1 == loc2,
-                _ => false,
-            },
-            _ => unimplemented!(),
-        }
-    }
-}
-
-impl Eq for SassError {}
-
 impl SassError {
     pub(crate) fn raw(self) -> (String, Span) {
         match self.kind {
@@ -76,7 +30,7 @@ impl SassError {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 enum SassErrorKind {
     /// A raw error with no additional metadata
     /// It contains only a `String` message and
@@ -86,7 +40,9 @@ enum SassErrorKind {
         message: String,
         loc: SpanLoc,
     },
-    IoError(io::Error),
+    // we put IoErrors in an `Rc` to allow it to be
+    // cloneable
+    IoError(Rc<io::Error>),
     FromUtf8Error(String),
 }
 
@@ -129,7 +85,7 @@ impl From<io::Error> for Box<SassError> {
     #[inline]
     fn from(error: io::Error) -> Box<SassError> {
         Box::new(SassError {
-            kind: SassErrorKind::IoError(error),
+            kind: SassErrorKind::IoError(Rc::new(error)),
         })
     }
 }
diff --git a/src/parse/value/eval.rs b/src/parse/value/eval.rs
index fae3f5c..acfba39 100644
--- a/src/parse/value/eval.rs
+++ b/src/parse/value/eval.rs
@@ -14,7 +14,7 @@ use crate::{
 
 use super::super::Parser;
 
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug)]
 pub(crate) enum HigherIntermediateValue {
     Literal(Value),
     /// A function that hasn't yet been evaluated
diff --git a/src/parse/value/parse.rs b/src/parse/value/parse.rs
index 4432f4b..ef7441f 100644
--- a/src/parse/value/parse.rs
+++ b/src/parse/value/parse.rs
@@ -26,7 +26,7 @@ use super::eval::{HigherIntermediateValue, ValueVisitor};
 
 use super::super::Parser;
 
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug)]
 enum IntermediateValue {
     Value(HigherIntermediateValue),
     Op(Op),
@@ -44,7 +44,7 @@ impl IntermediateValue {
 
 impl IsWhitespace for IntermediateValue {
     fn is_whitespace(&self) -> bool {
-        if self == &IntermediateValue::Whitespace {
+        if let IntermediateValue::Whitespace = self {
             return true;
         }
         false