1 files changed, 43 insertions, 0 deletions
diff --git a/rprt-engine/src/evaluate.rs b/rprt-engine/src/evaluate.rs
new file mode 100644
index 0000000..f6fee8a
--- /dev/null
+++ b/rprt-engine/src/evaluate.rs
@@ -0,0 +1,43 @@
+use crate::{
+    expression::Composite,
+    selection::{Selection, VectoriseError},
+    selection_functions::{evaluate_selection_function, SFError},
+    state::{EditorState, StateResult},
+};
+
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum EvaluationError {
+    #[error("{0}")]
+    SelectionFunctionError(VectoriseError<SFError>),
+    #[error("Not yet implemented {0}")]
+    UnimplementedError(&'static str),
+}
+
+pub fn evaluate(
+    es: &EditorState,
+    comp: Composite,
+    left: Option<Selection>,
+    right: Option<Selection>,
+) -> Result<StateResult, EvaluationError> {
+    match comp {
+        Composite::SelectionFunction {
+            func,
+            search_mod,
+            result_transform,
+        } => {
+            let sel =
+                evaluate_selection_function(es, func, search_mod, result_transform, left, right)
+                    .map_err(EvaluationError::SelectionFunctionError)?;
+            Ok((sel, Vec::new()))
+        }
+        Composite::TextFunction { func, swapped } => {
+            Err(EvaluationError::UnimplementedError("text function"))
+        }
+        Composite::Hook { kind, left, right } => Err(EvaluationError::UnimplementedError("hook")),
+        Composite::Train2 { f, g } => Err(EvaluationError::UnimplementedError("train2")),
+        Composite::Train3 { f, g, h } => Err(EvaluationError::UnimplementedError("train3")),
+        Composite::Group { operations } => Err(EvaluationError::UnimplementedError("group")),
+    }
+}