dsl: simplify trait further

dsl/src/dsl_error.rs

@@ -0,0 +1,25 @@
+use crate::*;
+
+/// DSL-specific error codes.
+#[derive(Error, Debug, Copy, Clone, PartialEq, PanicFmt)]
+pub enum DslError {
+
+    #[error("parse failed: not implemented")]
+    Unimplemented,
+
+    #[error("parse failed: empty")]
+    Empty,
+
+    #[error("parse failed: incomplete")]
+    Incomplete,
+
+    #[error("parse failed: unexpected character '{0}'")]
+    Unexpected(char, Option<usize>, Option<&'static str>),
+
+    #[error("parse failed: error #{0}")]
+    Code(u8),
+
+    #[error("end reached")]
+    End
+
+}