add `selection-start` and `selection-end` primitives

4 files changed, 56 insertions, 8 deletions

diff --git a/src/lisp/eval.rs b/src/lisp/eval.rs
index 0cf267c..b404662 100644
--- a/src/lisp/eval.rs
+++ b/src/lisp/eval.rs
@@ -217,12 +217,13 @@ where
 
     pub fn eval_for(&mut self, args: &[LispExpr]) -> Result<LispExpr, LispError> {
         let arity = Arity::Exact(2);
-        let valid_binding_stmt = |expr: &LispExpr| 
+        let valid_binding_stmt = |expr: &LispExpr| {
             matches!(
                 expr,
-                LispExpr::List(v) 
-                if v.len() == 2 
-                && matches!(v[0], LispExpr::Ident(_)));
+                LispExpr::List(v)
+                if v.len() == 2
+                && matches!(v[0], LispExpr::Ident(_)))
+        };
 
         if !arity.check(args) {
             Err(arity.to_error())
@@ -258,8 +259,8 @@ where
                 }
                 _ => {
                     error!("invalid for loop args");
-                    Err(EvalError::BadForm.into()) 
-                },
+                    Err(EvalError::BadForm.into())
+                }
             }
         }
     }
diff --git a/src/lisp/expr.rs b/src/lisp/expr.rs
index 692f951..d086ecf 100644
--- a/src/lisp/expr.rs
+++ b/src/lisp/expr.rs
@@ -310,6 +310,12 @@ impl TryFrom<LispExpr> for LispNumber {
     }
 }
 
+impl From<i64> for LispExpr {
+    fn from(num: i64) -> Self {
+        LispExpr::Number(num.into())
+    }
+}
+
 impl<'a> TryFrom<&'a LispExpr> for &'a LispNumber {
     type Error = LispError;
     fn try_from(value: &'a LispExpr) -> Result<Self, Self::Error> {
diff --git a/src/lisp/number.rs b/src/lisp/number.rs
index 4824e21..06c6baa 100644
--- a/src/lisp/number.rs
+++ b/src/lisp/number.rs
@@ -1,5 +1,6 @@
 use std::{
     cmp::{Eq, Ord, Ordering, PartialEq, PartialOrd},
+    convert::From,
     fmt,
     ops::{Add, Mul, Sub},
 };
@@ -113,3 +114,9 @@ impl fmt::Display for LispNumber {
         }
     }
 }
+
+impl From<i64> for LispNumber {
+    fn from(target: i64) -> Self {
+        LispNumber::Integer(target)
+    }
+}
diff --git a/src/lisp/prelude.rs b/src/lisp/prelude.rs
index e24ade5..1d37a32 100644
--- a/src/lisp/prelude.rs
+++ b/src/lisp/prelude.rs
@@ -1,6 +1,6 @@
 use crate::{
     bitmap::MapPoint,
-    brush::Brush,
+    brush::{Brush, RectSelectBrush},
     grid::GridKind,
     guide::Guide,
     lisp::{
@@ -11,7 +11,7 @@ use crate::{
     },
     primitive,
     undo::PaintRecord,
-    utils::load_script,
+    utils::{load_script, rect_coords},
 };
 
 use std::convert::TryInto;
@@ -437,6 +437,40 @@ pub fn new_env() -> Result<Environment, LispError> {
         }
     });
 
+    primitive!(env, Arity::Exact(0), "selection-start", |_, app| {
+        if let Brush::RectSelect(RectSelectBrush {
+            start: Some(s),
+            end: Some(e),
+            ..
+        }) = app.brush
+        {
+            let pt = rect_coords(s, e).0;
+            Ok(LispExpr::DottedList(vec![
+                (pt.x as i64).into(),
+                (pt.y as i64).into(),
+            ]))
+        } else {
+            Err(EvalError::CustomInternal("No active selection!").into())
+        }
+    });
+
+    primitive!(env, Arity::Exact(0), "selection-end", |_, app| {
+        if let Brush::RectSelect(RectSelectBrush {
+            start: Some(s),
+            end: Some(e),
+            ..
+        }) = app.brush
+        {
+            let pt = rect_coords(s, e).1;
+            Ok(LispExpr::DottedList(vec![
+                (pt.x as i64).into(),
+                (pt.y as i64).into(),
+            ]))
+        } else {
+            Err(EvalError::CustomInternal("No active selection!").into())
+        }
+    });
+
     primitive!(env, Arity::Exact(2), "range", |args, _| {
         if type_match!(
             args,