From e07dfb2a16e38c4101fd4d6c15440bab8636ecbd Mon Sep 17 00:00:00 2001
From: Giacomo Bellini <g.bellini@springmachinecontrol.com>
Date: Fri, 7 Apr 2023 18:10:09 +0200
Subject: [PATCH 1/2] Use decimal.TryParse to check if the given text is a
 number

---
 .../org.matheval/Functions/Impl/isnumberFunction.cs           | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/Math expression eval/org.matheval/Functions/Impl/isnumberFunction.cs b/Math expression eval/org.matheval/Functions/Impl/isnumberFunction.cs
index 3d50179..5626fb1 100644
--- a/Math expression eval/org.matheval/Functions/Impl/isnumberFunction.cs	
+++ b/Math expression eval/org.matheval/Functions/Impl/isnumberFunction.cs	
@@ -24,7 +24,6 @@ THE SOFTWARE.
 using org.matheval.Common;
 using System;
 using System.Collections.Generic;
-using System.Text.RegularExpressions;
 
 namespace org.matheval.Functions
 {
@@ -52,8 +51,7 @@ public List<FunctionDef> GetInfo()
         /// <returns>Value</returns>
         public Object Execute(Dictionary<string, Object> args, ExpressionContext dc)
         {
-            Regex rg = new Regex("^-?\\d*(\\.\\d+)+$");
-            return rg.IsMatch(Afe_Common.ToString(args[Afe_Common.Const_Key_One], dc.WorkingCulture));
+            return decimal.TryParse(Afe_Common.ToString(args[Afe_Common.Const_Key_One], dc.WorkingCulture), out _);
         }
     }
 }

From 32e1d67dda449b51007edef688c9507c6d44f2e9 Mon Sep 17 00:00:00 2001
From: Giacomo Bellini <g.bellini@springmachinecontrol.com>
Date: Fri, 7 Apr 2023 18:10:37 +0200
Subject: [PATCH 2/2] Added a bunch of tests for function isnumber and value

---
 Math expression eval/UnitTest/TestAll.cs | 53 ++++++++++++++++++++----
 1 file changed, 46 insertions(+), 7 deletions(-)

diff --git a/Math expression eval/UnitTest/TestAll.cs b/Math expression eval/UnitTest/TestAll.cs
index 48fef10..2d08a25 100644
--- a/Math expression eval/UnitTest/TestAll.cs	
+++ b/Math expression eval/UnitTest/TestAll.cs	
@@ -410,10 +410,6 @@ public void Math_Bitwise_Test()
 
             Expression expr6 = new Expression("BITRSHIFT(13,2)");
             Assert.AreEqual(3, expr6.Eval<int>());
-
-            Expression expr7 = new Expression("VALUE(\"123\")");
-            Assert.AreEqual(123, expr7.Eval<int>());
-
         }
 
         [TestMethod]
@@ -920,6 +916,27 @@ public void Text_Function_IsNumber_Test()
             Expression expr1 = new Expression("ISNUMBER(\"0.23\")");
             Assert.AreEqual(true, expr1.Eval<bool>());
 
+            expr1.SetFomular("ISNUMBER(\"23\")");
+            Assert.AreEqual(true, expr1.Eval<bool>());
+
+            expr1.SetFomular("ISNUMBER(\".23\")");
+            Assert.AreEqual(true, expr1.Eval<bool>());
+
+            expr1.SetFomular("ISNUMBER(\"23.\")");
+            Assert.AreEqual(true, expr1.Eval<bool>());
+
+            expr1.SetFomular("ISNUMBER(\"-23\")");
+            Assert.AreEqual(true, expr1.Eval<bool>());
+
+            expr1.SetFomular("ISNUMBER(\"-.23\")");
+            Assert.AreEqual(true, expr1.Eval<bool>());
+
+            expr1.SetFomular("ISNUMBER(\"-23.\")");
+            Assert.AreEqual(true, expr1.Eval<bool>());
+
+            expr1.SetFomular("ISNUMBER(\".23.\")");
+            Assert.AreEqual(false, expr1.Eval<bool>());
+
             expr1.SetFomular("ISNUMBER(\"0.2a3\")");
             Assert.AreEqual(false, expr1.Eval<bool>());
 
@@ -1150,6 +1167,28 @@ public void Text_Function_Isblank_Test()
             Assert.AreEqual(false, expr1.Eval<bool>());
         }
 
+        [TestMethod]
+        public void Text_Function_Value_Test()
+        {
+            Expression expr1 = new Expression("VALUE(\"123\")");
+            Assert.AreEqual(123, expr1.Eval<int>());
+
+            expr1.SetFomular("VALUE(\"123.123\")");
+            Assert.AreEqual(123.123m, expr1.Eval<decimal>());
+
+            expr1.SetFomular("VALUE(\".123\")");
+            Assert.AreEqual(0.123m, expr1.Eval<decimal>());
+
+            expr1.SetFomular("VALUE(\"-.123\")");
+            Assert.AreEqual(-0.123m, expr1.Eval<decimal>());
+
+            expr1.SetFomular("VALUE(\"123.\")");
+            Assert.AreEqual(123, expr1.Eval<int>());
+
+            expr1.SetFomular("VALUE(\".123.\")");
+            Assert.ThrowsException<Exception>(() => expr1.Eval<int>());
+        }
+
         [TestMethod]
         public void Literals_Operation_Test()
         {
@@ -1169,19 +1208,19 @@ public void Or_Operator_Test()
                 .Bind("a", 0)
                 .Bind("b", 0);
             Assert.AreEqual(false, expr.Eval<bool>());
-            
+
             // false, true = true
             var expr2 = new Expression("OR (a>0, b>0)")
                 .Bind("a", 0)
                 .Bind("b", 1);
             Assert.AreEqual(true, expr2.Eval<bool>());
-            
+
             // true, false = true
             var expr3 = new Expression("OR (a>0, b>0)")
                 .Bind("a", 1)
                 .Bind("b", 0);
             Assert.AreEqual(true, expr3.Eval<bool>());
-            
+
             // true, true = true
             var expr4 = new Expression("OR (a>0, b>0)")
                 .Bind("a", 1)