assembler: we failing DSA with this one

assembler/src/error.rs

@@ -3,7 +3,7 @@
 
 use std::fmt::{Debug, Display};
 
-use crate::source::source_info::SourceInfo;
+use crate::source::{source_info::SourceInfo, tokeniser::error::TokeniserError};
 
 /// An error that may occur during the assembly of a set of source files.
 #[derive(Debug)]
@@ -13,26 +13,38 @@ pub struct AssembleError {
     source_info: Option<SourceInfo>,
     /// The type of assembly error that occurred.
     kind: AssembleErrorKind,
-    /// The formatter to handle printing the error.
-    formatter: Box<dyn ErrorFormatter>,
 }
 
 impl AssembleError {
-    pub fn new_source_error(source_info: SourceInfo, kind: AssembleErrorKind) -> Self {
+    #[must_use]
+    pub const fn new_source_error(
+        source_info: SourceInfo,
+        kind: AssembleErrorKind,
+    ) -> Self {
         Self {
             source_info: Some(source_info),
             kind,
-            formatter,
         }
     }
 
-    pub fn new_other_error(kind: AssembleErrorKind) {}
+    #[must_use]
+    pub const fn new_other_error(kind: AssembleErrorKind) -> Self {
+        Self {
+            source_info: None,
+            kind,
+        }
+    }
 }
 
 impl Display for AssembleError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        self.formatter
-            .write(f, self.source_info.as_ref(), &self.kind)
+        if let Some(info) = &self.source_info {
+            write!(f, "at {info}")?;
+        }
+
+        write!(f, "{}", self.kind)?;
+
+        Ok(())
     }
 }
 
@@ -42,7 +54,29 @@ impl std::error::Error for AssembleError {}
 /// Different types of errors that may occur when assembling a set of input source files.
 #[non_exhaustive]
 #[derive(Debug)]
-pub enum AssembleErrorKind {}
+pub enum AssembleErrorKind {
+    /// Usually unexpected I/O errors. Not normally recoverable.
+    IO(std::io::Error),
+    /// Errors emitted from the [`Tokeniser`].
+    Tokenise(TokeniserError),
+}
+
+impl Display for AssembleErrorKind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Tokenise(why) => write!(f, "tokeniser error: {why}"),
+            _ => write!(
+                f,
+                "unhandled error type in Display implementation! See error.rs!"
+            ),
+        }
+    }
+}
+
+impl From<std::io::Error> for AssembleErrorKind {
+    fn from(err: std::io::Error) -> Self {
+        Self::IO(err)
+    }
+}
 
 pub mod conversions;
-pub mod formatters;