1 files changed, 37 insertions, 0 deletions
diff --git a/src/diagnostics/non_alphabetic_attribute_name.rs b/src/diagnostics/non_alphabetic_attribute_name.rs
new file mode 100644
index 0000000..1cb31d9
--- /dev/null
+++ b/src/diagnostics/non_alphabetic_attribute_name.rs
@@ -0,0 +1,37 @@
+use miette::Diagnostic;
+use thiserror::Error;
+
+use crate::{
+	diagnostics::TokenDiagnostic,
+	tokenize::{AttributeToken, AttributeTokenType, Span},
+};
+
+#[derive(Error, Debug, Diagnostic)]
+#[error("Attribute names must be alphabetic")]
+#[diagnostic(code(NonAlphabeticAttributeName), severity(Error))]
+pub struct NonAlphabeticAttributeName {
+	#[label(
+		primary,
+		"attribute names must only contain uppercase and lowercase letters"
+	)]
+	attribute_name: Span,
+}
+
+impl TokenDiagnostic for NonAlphabeticAttributeName {
+	fn handle_attribute_token(token: &AttributeToken<'_>) -> Option<Self> {
+		let AttributeTokenType::Identifier { lowercase_name, .. } = token.ty else {
+			return None;
+		};
+
+		if lowercase_name
+			.chars()
+			.all(|char| char.is_ascii_alphabetic())
+		{
+			return None;
+		}
+
+		Some(Self {
+			attribute_name: token.span,
+		})
+	}
+}