From 3576ddaf317418be793f8516afd2f3d67a408615 Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Sat, 25 Aug 2018 21:15:55 +0300
Subject: [PATCH] Added extension to field to use numbers as first class
 citizens

---
 .../src/main/kotlin/scientifik/kmath/operations/Algebra.kt | 7 +++++--
 .../kmath/expressions/FieldExpressionContextTest.kt        | 2 +-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/kmath-common/src/main/kotlin/scientifik/kmath/operations/Algebra.kt b/kmath-common/src/main/kotlin/scientifik/kmath/operations/Algebra.kt
index 985cf3b14..4613dda7c 100644
--- a/kmath-common/src/main/kotlin/scientifik/kmath/operations/Algebra.kt
+++ b/kmath-common/src/main/kotlin/scientifik/kmath/operations/Algebra.kt
@@ -6,7 +6,7 @@ package scientifik.kmath.operations
  * @param T the self type of the element
  * @param S the type of mathematical context for this element
  */
-interface MathElement<T, S>{
+interface MathElement<T, S> {
     /**
      * The context this element belongs to
      */
@@ -53,7 +53,7 @@ interface Space<T> {
  * @param T  self type of the element. Needed for static type checking
  * @param S the type of space
  */
-interface SpaceElement<T, S : Space<T>>: MathElement<T,S> {
+interface SpaceElement<T, S : Space<T>> : MathElement<T, S> {
 
     /**
      * Self value. Needed for static type checking. Needed to avoid type erasure on JVM.
@@ -101,6 +101,9 @@ interface Field<T> : Ring<T> {
 
     operator fun T.div(b: T): T = divide(this, b)
     operator fun Number.div(b: T) = this * divide(one, b)
+
+    operator fun T.plus(b: Number) = this.plus(b * one)
+    operator fun Number.plus(b: T) = b + this
 }
 
 /**
diff --git a/kmath-common/src/test/kotlin/scientifik/kmath/expressions/FieldExpressionContextTest.kt b/kmath-common/src/test/kotlin/scientifik/kmath/expressions/FieldExpressionContextTest.kt
index 5e9832604..3d68a4674 100644
--- a/kmath-common/src/test/kotlin/scientifik/kmath/expressions/FieldExpressionContextTest.kt
+++ b/kmath-common/src/test/kotlin/scientifik/kmath/expressions/FieldExpressionContextTest.kt
@@ -10,7 +10,7 @@ class FieldExpressionContextTest {
         val context = FieldExpressionContext(DoubleField)
         val expression = with(context) {
             val x = variable("x", 2.0)
-            x * x + 2 * x + 1.0 * one
+            x * x + 2 * x + 1.0
         }
         assertEquals(expression("x" to 1.0), 4.0)
         assertEquals(expression(), 9.0)