feat: Implement explicit list_extend()

Cleaned and refactored code for several list-methods.

Keep the established behavior that `list_add()` and `list_iadd()` either push or extend.

Squashed commit of the following:

commit af1256d32c51ae39d2c8a585ae69737526849c36
Author: Jan Max Meyer <[email protected]>
Date:   Sun Dec 29 13:20:26 2024 +0100

    Finalize `list_extend()`

commit d26ad4a0db30df5313ac9af5fda3f10c7c9e63f8
Author: Jan Max Meyer <[email protected]>
Date:   Sun Dec 29 11:49:22 2024 +0100

    .

commit 7ad5ba4eaaeb4e77084bb73293aa1b06297aba7f
Author: Jan Max Meyer <[email protected]>
Date:   Sun Dec 29 00:32:44 2024 +0100

    Implement and use of list_extend()

Author: phorward

src/_builtins.rs

@@ -6,7 +6,7 @@
 use crate::builtin::Builtin;
 
 /*GENERATE cargo run -- _builtins.tok -- `find . -name "*.rs"` */
-pub static BUILTINS: [Builtin; 69] = [
+pub static BUILTINS: [Builtin; 70] = [
     Builtin {
         name: "Float",
         func: crate::value::token::tokay_token_float,
@@ -167,6 +167,10 @@ pub static BUILTINS: [Builtin; 69] = [
         name: "list_clone",
         func: crate::value::list::List::tokay_method_list_clone,
     },
+    Builtin {
+        name: "list_extend",
+        func: crate::value::list::List::tokay_method_list_extend,
+    },
     Builtin {
         name: "list_flatten",
         func: crate::value::list::List::tokay_method_list_flatten,

src/prelude.tok

@@ -48,7 +48,7 @@ Repeat : @<
 
     loop {
         P {
-            res.push($1)
+            res.push($1)  # explicit push!
             cnt += 1
             if max && cnt == max break
         }
@@ -85,7 +85,7 @@ Opt : @<P>{ P | Empty }
 List : @<P, Separator: (',' _), empty: true> {
     Self Separator P   $1 + $3
     if empty (Self Separator)   # allows for trailing Separator
-    P  ($1, )
+    P  $1,
 }
 
 # Parse keywords, which may not be the prefix of another identifier.

src/value/list.rs

@@ -1,5 +1,6 @@
 //! List object
 use super::{BoxedObject, Iter, Object, RefValue};
+use crate::value;
 use tokay_macros::tokay_method;
 extern crate self as tokay;
 
@@ -92,7 +93,9 @@ impl List {
         if let Some(list) = borrowed.object::<List>() {
             Ok(RefValue::from(list.clone()))
         } else {
-            Ok(RefValue::from(List { list: vec![list.clone()] }))
+            Ok(RefValue::from(List {
+                list: vec![list.clone()],
+            }))
         }
     });
 
@@ -101,6 +104,8 @@ impl List {
 
         Ok(RefValue::from(if let Some(list) = list.object::<List>() {
             list.len()
+        } else if list.is_void() {
+            0
         } else {
             1
         }))
@@ -184,7 +189,7 @@ impl List {
             }
         }
 
-        // Extend in-place when possible.
+        // Append or extend in-place when possible.
         if let (Ok(mut inner), Ok(to_append)) = (list.try_borrow_mut(), append.try_borrow()) {
             let inner = inner.object_mut::<List>().unwrap();
 
@@ -218,7 +223,7 @@ impl List {
 
         // In case list is not a list, make it a list.
         if !list.is("list") {
-            list = Self::list(vec![list], None)?;
+            list = RefValue::from(List::from(list));
         }
 
         let mut list = list.borrow().object::<List>().unwrap().clone();
@@ -238,22 +243,20 @@ impl List {
         Ok(RefValue::from(list))
     });
 
+    /** Explicitly pushes `item` to `list`.
+
+    When `index` is provided, the value is inserted at the given offset,
+    otherwise it is appended (pushed) to the list's end. */
     tokay_method!("list_push : @list, item, index=void", {
         // Don't push void
         if item.is_void() {
-            return Ok(list);
+            return Ok(value![void]);
         }
 
-        // In case list is not a list, make it a list.
-        if !list.is("list") {
-            list = Self::list(vec![list], None)?;
-        }
-
-        // list_push returns the list itself, therefore this block.
-        {
-            let mut list = list.borrow_mut();
-            let list = list.object_mut::<List>().unwrap();
+        let mut list = list.borrow_mut();
 
+        // If first parameter is not a list, just do nothing!
+        if let Some(list) = list.object_mut::<List>() {
             if index.is_void() {
                 list.push(item);
             } else {
@@ -272,9 +275,64 @@ impl List {
             }
         }
 
-        Ok(list)
+        Ok(value![void])
     });
 
+    /** Explicitly extends `extend` to `list`.
+
+    When `index` is provided, the list behind extend is inserted at the given offset,
+    otherwise it is extended to the list's end. */
+    tokay_method!("list_extend : @list, extend, index=void", {
+        // Don't extend void
+        if extend.is_void() {
+            return Ok(value![void]);
+        }
+
+        // In case extend is not a list, make it a list.
+        if !extend.is("list") {
+            extend = RefValue::from(List::from(extend));
+        }
+
+        let mut list = list.borrow_mut();
+
+        // If first parameter is not a list, just do nothing!
+        if let Some(list) = list.object_mut::<List>() {
+            let extend = extend.borrow();
+            let extend = extend.object::<List>().unwrap();
+
+            list.reserve(extend.len());
+
+            if index.is_void() {
+                for item in extend.iter() {
+                    if !item.is_void() {
+                        list.push(item.clone());
+                    }
+                }
+            } else {
+                let mut index = index.to_usize()?;
+                let len = list.len();
+
+                if index > len {
+                    return Err(format!(
+                        "{} provided index {} out of range in list sized {}",
+                        __function, index, len
+                    )
+                    .into());
+                }
+
+                for item in extend.iter() {
+                    if !item.is_void() {
+                        list.insert(index, item.clone());
+                        index += 1;
+                    }
+                }
+            }
+        }
+
+        Ok(value![void])
+    });
+
+    /** Pops item off a list. */
     tokay_method!("list_pop : @list, index=void", {
         let index = if index.is_void() {
             None
@@ -287,39 +345,28 @@ impl List {
                 return Ok(list); // "pops" the list, which is not a list
             }
 
-            return Err(format!(
-                "{} provided index {} out of range",
-                __function,
-                index.unwrap()
-            )
-            .into());
+            return Ok(value![void]);
         }
 
         let mut list = list.borrow_mut();
         let list = list.object_mut::<List>().unwrap();
 
         // Either pop or remove, regarding index setting.
-        match index {
+        Ok(match index {
             None => match list.pop() {
-                Some(item) => Ok(item),
-                None => {
-                    return Err(format!("{} can't pop off empty list", __function).into());
-                }
+                Some(item) => item,
+                None => value![void],
             },
             Some(index) => {
                 let len = list.len();
 
-                if index >= len {
-                    return Err(format!(
-                        "{} provided index {} out of range of list sized {}",
-                        __function, index, len
-                    )
-                    .into());
+                if index < len {
+                    list.remove(index)
+                } else {
+                    value![void]
                 }
-
-                Ok(list.remove(index))
             }
-        }
+        })
     });
 
     tokay_method!("list_sort : @list", {
@@ -379,6 +426,7 @@ impl From<RefValue> for List {
                 let list = list.object::<List>().unwrap();
                 (*list).clone()
             }
+            "void" => Self { list: Vec::new() },
             _ => Self {
                 list: vec![refvalue.clone()],
             },

tests/list_extend.tok

@@ -0,0 +1,19 @@
+#testmode:repl
+
+l = 1,2,3
+l
+
+l.extend(4)
+l
+
+l.extend((5,6,7))
+l
+
+l.extend((10, 20, 30), 1)
+l
+
+#---
+#(1, 2, 3)
+#(1, 2, 3, 4)
+#(1, 2, 3, 4, 5, 6, 7)
+#(1, 10, 20, 30, 2, 3, 4, 5, 6, 7)

tests/list_len.tok

@@ -1,10 +1,11 @@
 #testmode:repl
 
 list().len
-().len
+(,).len
 (1,).len
 (1, 2, 3).len
 list_len(5)
+list_len(void)
 
 #---
 
@@ -13,3 +14,4 @@ list_len(5)
 #1
 #3
 #1
+#0

tests/list_pop.tok

@@ -1,21 +1,22 @@
 #testmode:repl
 
 l = (1,2,3,4); l.pop() l.pop(1)
+
 l = (1,2,3,4)
 l.pop(0)
 l.pop()
-l.pop(2)
+type(l.pop(2))
 l
 
 list_pop(1)
-list_pop(1, 1)
+type(list_pop(1, 1))
 
 #---
 
 #(4, 2)
 #1
 #4
-#ERR:Line 1, column 3: list_pop() provided index 2 out of range of list sized 2
+#"void"
 #(2, 3)
 #1
-#ERR:Line 1, column 1: list_pop() provided index 1 out of range
+#"void"

tests/list_push.tok

@@ -1,15 +1,25 @@
 #testmode:repl
 
-l = (1,)
+l = 1,
+l
+
 l.push(2)
+l
+
 l.push((3, 4))
+l
+
+l.push(99, 1)
+l
 
-list_push((1,2,3), 99, 1)
-list_push((1,2,3), 99, 4)
+l.push(99, 10)
+l
 
 #---
 
+#(1, )
 #(1, 2)
 #(1, 2, (3, 4))
-#(1, 99, 2, 3)
-#ERR:Line 1, column 1: list_push() provided index 4 out of range in list sized 3
+#(1, 99, 2, (3, 4))
+#ERR:Line 1, column 3: list_push() provided index 10 out of range in list sized 4
+#(1, 99, 2, (3, 4))