From 8f7726eab5978bb06206d25bc29cec8d4b40c2a6 Mon Sep 17 00:00:00 2001
From: bakk <bakk@tuta.io>
Date: Sun, 23 Jan 2022 00:32:58 +0100
Subject: [PATCH] Added 'length' function and added 'permutations' as an alias
 to 'perms' function

---
 kalk/src/prelude/mod.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/kalk/src/prelude/mod.rs b/kalk/src/prelude/mod.rs
index 22dabc2..df1d18a 100644
--- a/kalk/src/prelude/mod.rs
+++ b/kalk/src/prelude/mod.rs
@@ -74,6 +74,7 @@ lazy_static! {
         m.insert("iverson", (UnaryFuncInfo(iverson, Other), ""));
         m.insert("Im", (UnaryFuncInfo(im, Other), ""));
         m.insert("ln", (UnaryFuncInfo(ln, Other), ""));
+        m.insert("length", (UnaryFuncInfo(length, Other), ""));
         m.insert("log", (UnaryFuncInfo(log, Other), ""));
         m.insert("Re", (UnaryFuncInfo(re, Other), ""));
         m.insert("round", (UnaryFuncInfo(round, Other), ""));
@@ -109,6 +110,7 @@ lazy_static! {
         m.insert("max", VectorFuncInfo(max, Other));
         m.insert("min", VectorFuncInfo(min, Other));
         m.insert("perms", VectorFuncInfo(perms, Other));
+        m.insert("permutations", VectorFuncInfo(perms, Other));
         m
     };
 }
@@ -720,6 +722,14 @@ pub mod funcs {
         }
     }
 
+    pub fn length(x: KalkValue) -> KalkValue {
+        match x {
+            KalkValue::Vector(values) => KalkValue::from(values.len() as f64),
+            KalkValue::Matrix(rows) => KalkValue::from(rows.len() as f64),
+            _ => KalkValue::from(0f64),
+        }
+    }
+
     pub fn max(x: KalkValue) -> KalkValue {
         let values = as_vector_or_return!(x);
         let mut max = &values[0];