1 files changed, 26 insertions, 21 deletions
diff --git a/rprt-engine/src/selection_functions/result_transformation.rs b/rprt-engine/src/selection_functions/result_transformation.rs
index c150916..b437afd 100644
--- a/rprt-engine/src/selection_functions/result_transformation.rs
+++ b/rprt-engine/src/selection_functions/result_transformation.rs
@@ -1,16 +1,20 @@
 use crate::{
     buffer::BufferID,
-    selection::{Interval, Selection},
-    selection_functions::types::{SFArguments, SFError, SFResult},
+    selection::{Interval, Selection, Vectorisable},
+    selection_functions::types::SelectionFunctionError,
     state::EditorState,
 };
 
-pub fn complement_transform(es: &EditorState, result: Selection) -> SFResult {
-    fn complement_rank0(
+struct Complement;
+
+impl Vectorisable<(), SelectionFunctionError> for Complement {
+    fn rank0(
+        &self,
+        _param: &(),
         es: &EditorState,
         buffer_id: BufferID,
         pos: usize,
-    ) -> Result<Selection, SFError> {
+    ) -> Result<Selection, SelectionFunctionError> {
         if let Some(buf) = es.get_buffer(buffer_id) {
             let mut ranges = Vec::new();
             if pos > 0 {
@@ -22,15 +26,17 @@ pub fn complement_transform(es: &EditorState, result: Selection) -> SFResult {
             }
             Ok(Selection::Vectors { buffer_id, ranges })
         } else {
-            Err(SFError::BufferNotFound(buffer_id))
+            Err(SelectionFunctionError::BufferNotFound(buffer_id))
         }
     }
 
-    fn complement_rank1(
+    fn rank1(
+        &self,
+        _param: &(),
         es: &EditorState,
         buffer_id: BufferID,
         interval: &Interval,
-    ) -> Result<Selection, SFError> {
+    ) -> Result<Selection, SelectionFunctionError> {
         if let Some(buf) = es.get_buffer(buffer_id) {
             let max_pos = buf.max_pos();
             if interval.start == 0 && interval.end >= max_pos {
@@ -50,25 +56,24 @@ pub fn complement_transform(es: &EditorState, result: Selection) -> SFResult {
             }
             Ok(Selection::Vectors { buffer_id, ranges })
         } else {
-            Err(SFError::BufferNotFound(buffer_id))
+            Err(SelectionFunctionError::BufferNotFound(buffer_id))
         }
     }
+}
 
-    result.vectorise(es, complement_rank0, complement_rank1)
+pub fn complement_transform(
+    es: &EditorState,
+    result: Selection,
+) -> Result<Selection, SelectionFunctionError> {
+    Complement.vectorise(&(), es, &result)
 }
 
-pub fn conditional_transform(mut result: Selection, arg: &SFArguments) -> SFResult {
+pub fn conditional_transform(
+    mut result: Selection,
+    left: Option<&Selection>,
+) -> Result<Selection, SelectionFunctionError> {
     if !result.is_empty() {
-        Ok(match arg {
-            // TODO: think about this niladic case?
-            SFArguments::Niladic { .. } => Selection::empty(),
-            SFArguments::Monadic { es: _, left } => left.clone(),
-            SFArguments::Dyadic {
-                es: _,
-                left,
-                right: _,
-            } => left.clone(),
-        })
+        Ok(left.cloned().unwrap_or_else(Selection::empty))
     } else {
         Ok(result)
     }