Move AstFailure to error module

Signed-off-by: Marcel Müller <neikos@neikos.email>

src/errors.rs

@@ -0,0 +1,52 @@
+use thiserror::Error;
+
+use crate::parser::AstError;
+
+#[derive(Debug, Error)]
+pub struct AstFailure {
+    errors: Vec<AstError>,
+}
+
+impl std::fmt::Display for AstFailure {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("TODO")
+    }
+}
+
+impl AstFailure {
+    pub(crate) fn from_errors(errors: Vec<AstError>) -> AstFailure {
+        AstFailure { errors }
+    }
+
+    pub fn to_report(&self, source: &str) -> String {
+        let reports = self
+            .errors
+            .iter()
+            .map(|error| {
+                annotate_snippets::Level::ERROR
+                    .primary_title(
+                        error
+                            .message
+                            .as_deref()
+                            .unwrap_or("An error occurred while producing an Ast"),
+                    )
+                    .element(
+                        annotate_snippets::Snippet::source(source).annotation(
+                            annotate_snippets::AnnotationKind::Primary
+                                .span(error.span.clone().map(|s| s.range).unwrap_or_else(|| 0..0)),
+                        ),
+                    )
+                    .elements(
+                        error
+                            .help
+                            .as_ref()
+                            .map(|help| annotate_snippets::Level::HELP.message(help)),
+                    )
+            })
+            .collect::<Vec<_>>();
+
+        let renderer = annotate_snippets::Renderer::styled()
+            .decor_style(annotate_snippets::renderer::DecorStyle::Unicode);
+        renderer.render(&reports)
+    }
+}