Assignment and construction from one or two integer expressions

mpir.net/mpir.net-tests/HugeRationalTests/Assignment.cs

@@ -71,6 +71,21 @@ namespace MPIR.Tests.HugeRationalTests
                 Assert.AreEqual("222509832503450298345029835740293845720/1", b.ToString());
             }
         }
+
+        [TestMethod]
+        public void RationalAssignInt2()
+        {
+            using (var a = new HugeInt("222509832503450298345029835740293845719"))
+            using (var d = new HugeInt("115756986668303657898962467957"))
+            using (var b = new HugeRational("1/3"))
+            {
+                b.SetTo(a, d);
+                Assert.AreEqual("222509832503450298345029835740293845719/115756986668303657898962467957", b.ToString());
+                b.SetTo(b.Numerator - b.Denominator, b.Denominator * 5);
+                Assert.AreEqual(a - d, b.Numerator);
+                Assert.AreEqual(d * 5, b.Denominator);
+            }
+        }
         //more tests coming here
     }
 }

mpir.net/mpir.net-tests/HugeRationalTests/ConstructionAndDisposal.cs

@@ -248,5 +248,27 @@ namespace MPIR.Tests.HugeRationalTests
                 Assert.AreEqual(a + 1, b);
             }
         }
+
+        [TestMethod]
+        public void RationalConstructorFromIntExpression()
+        {
+            using (var a = new HugeInt("2340958273409578234095823045723490587"))
+            using (var b = new HugeRational(a + 1))
+            {
+                Assert.AreEqual("2340958273409578234095823045723490588/1", b.ToString());
+            }
+        }
+
+        [TestMethod]
+        public void RationalConstructorFromIntExpression2()
+        {
+            using (var a = new HugeInt("2340958273409578234095823045723490587"))
+            using (var d = new HugeInt("362736035870515331128527330659"))
+            using (var b = new HugeRational(a + 2, d * 2))
+            {
+                Assert.AreEqual(a + 2, b.Numerator);
+                Assert.AreEqual(d * 2, b.Denominator);
+            }
+        }
     }
 }

mpir.net/mpir.net/HugeRational.cpp

@@ -48,6 +48,20 @@ namespace MPIR
         MP(init)(_value);
         value->AssignTo(_value);
     }
+
+    MPTYPE::MPTYPE(IntegerExpression^ value)
+    {
+        AllocateStruct();
+        MP(init)(_value);
+        SetTo(value);
+    }
+
+    MPTYPE::MPTYPE(IntegerExpression^ numerator, IntegerExpression^ denominator)
+    {
+        AllocateStruct();
+        MP(init)(_value);
+        SetTo(numerator, denominator);
+    }
     
     MPTYPE^ MPTYPE::Allocate(mp_bitcnt_t numeratorBits, mp_bitcnt_t denominatorBits)
     {

mpir.net/mpir.net/HugeRational.h

@@ -908,6 +908,20 @@ namespace MPIR
             /// <param name="value">the expression that will be computed, and the result set as the initial value of the new instance.</param>
             MPTYPE(MPEXPR_NAME^ value);
 
+            /// <summary>
+            /// Initializes a new rational instance and sets its value to the result of computing the source expression.
+            /// </summary>
+            /// <param name="value">the expression that will be computed, and the result set as the initial value of the new instance.</param>
+            MPTYPE(IntegerExpression^ value);
+
+            /// <summary>
+            /// Constructs and returns a new rational instance with its value set to <paramref name="numerator"/> / <paramref name="denominator"/>.
+            /// <para>If the fraction is not in canonical form, Canonicalize() must be called.</para>
+            /// </summary>
+            /// <param name="numerator">Numerator for the initial value for the new rational instance</param>
+            /// <param name="denominator">Denominator for the initial value for the new rational instance</param>
+            MPTYPE(IntegerExpression^ numerator, IntegerExpression^ denominator);
+
             /// <summary>
             /// Constructs and returns a new rational instance with its value set to <paramref name="numerator"/> / <paramref name="denominator"/>.
             /// <para>If the fraction is not in canonical form, Canonicalize() must be called.</para>
@@ -1156,9 +1170,25 @@ namespace MPIR
             /// <param name="value">new value for the object</param>
             void SetTo(IntegerExpression^ value)
             {
+                value->AssignTo(&_value->_mp_num);
+                mpz_set_ui(&_value->_mp_den, 1);
+            }
+
+            /// <summary>
+            /// Sets the value of the raitonal object.
+            /// <para>Do not change the value of an object while it is contained in a hash table, because that changes its hash code.
+            /// </para>If the fraction is not in canonical form, Canonicalize() must be called.
+            /// </summary>
+            /// <param name="numerator">Numerator for the new value for the object</param>
+            /// <param name="denominator">Denominator for the new value for the object</param>
+            void SetTo(IntegerExpression^ numerator, IntegerExpression^ denominator)
+            {
+                //use context in case source expressions reference the previous numerator or denominator of the rational
                 EvaluationContext context;
-                value->AssignToInteger(context);
-                MP(set_z)(_value, CTXTI(0));
+                numerator->AssignToInteger(context);
+                denominator->AssignToInteger(context);
+                mpz_set(&_value->_mp_num, CTXTI(0));
+                mpz_set(&_value->_mp_den, CTXTI(1));
             }
 
             /// <summary>