feat: list_index()-function

Author: phorward

src/_builtins.rs

@@ -6,7 +6,7 @@
 use crate::builtin::Builtin;
 
 /*GENERATE cargo run -- src/_builtins.tok -- `find src -name "*.rs"` */
-pub static BUILTINS: [Builtin; 70] = [
+pub static BUILTINS: [Builtin; 71] = [
     Builtin {
         name: "Float",
         func: crate::value::token::tokay_token_float,
@@ -183,6 +183,10 @@ pub static BUILTINS: [Builtin; 70] = [
         name: "list_iadd",
         func: crate::value::list::List::tokay_method_list_iadd,
     },
+    Builtin {
+        name: "list_index",
+        func: crate::value::list::List::tokay_method_list_index,
+    },
     Builtin {
         name: "list_len",
         func: crate::value::list::List::tokay_method_list_len,

src/value/list.rs

@@ -382,6 +382,26 @@ impl List {
 
         Ok(list)
     });
+
+    /** Find `item` in `list` and return its offset.
+
+    In case `item` is not in the list, -1 is returned.
+    */
+    tokay_method!("list_index : @list, item", {
+        let list = list.borrow();
+
+        if let Some(list) = list.object::<List>() {
+            if let Some(index) = list
+                .list
+                .iter()
+                .position(|val| *val.borrow() == *item.borrow())
+            {
+                return Ok(value![index]);
+            }
+        }
+
+        Ok(value![-1])
+    });
 }
 
 impl std::ops::Deref for List {

tests/list_index.tok

@@ -0,0 +1,18 @@
+#testmode:repl
+
+l = 1,2,3
+l.index(2)
+l.index(4)
+
+l = "Esel", "Frank", (42, 5)
+l.index("Esel")
+l.index((42, 5))
+l.index(9)
+
+#---
+
+#1
+#-1
+#0
+#2
+#-1