Subtraction of two chars, new conversions, and fixes for dynamic operator invocations and QuotationToExpression

src/fsharp/ConstraintSolver.fs

@@ -424,7 +424,7 @@ let isFpTy g ty =
 
 /// decimal or decimal<_>
 let isDecimalTy g ty = 
-    typeEquivAux EraseMeasures g g.decimal_ty ty 
+    typeEquivAux EraseMeasures g g.decimal_ty ty
 
 let IsNonDecimalNumericOrIntegralEnumType g ty = IsIntegerOrIntegerEnumTy g ty || isFpTy g ty
 
@@ -439,7 +439,7 @@ let IsRelationalType g ty = IsNumericType g ty || isStringTy g ty || isCharTy g
 let IsCharOrStringType g ty = isCharTy g ty || isStringTy g ty
 
 /// Checks the argument type for a built-in solution to an op_Addition, op_Subtraction or op_Modulus constraint.
-let IsAddSubModType nm g ty = IsNumericOrIntegralEnumType g ty || (nm = "op_Addition" && IsCharOrStringType g ty)
+let IsAddSubModType nm g ty = IsNumericOrIntegralEnumType g ty || (nm = "op_Addition" && IsCharOrStringType g ty) || (nm = "op_Subtraction" && isCharTy g ty)
 
 /// Checks the argument type for a built-in solution to a bitwise operator constraint
 let IsBitwiseOpType g ty = IsIntegerOrIntegerEnumTy g ty || (isEnumTy g ty)
@@ -1564,25 +1564,30 @@ and SolveMemberConstraint (csenv: ConstraintSolverEnv) ignoreUnresolvedOverload
           do! SolveTypeEqualsTypeKeepAbbrevs csenv ndeep m2 trace rty argty
           return TTraitBuiltIn
 
+      // Conversions from non-decimal numbers / strings / chars to non-decimal numbers / chars are built-in
       | _, _, false, "op_Explicit", [argty] 
           when (// The input type. 
                 (IsNonDecimalNumericOrIntegralEnumType g argty || isStringTy g argty || isCharTy g argty) &&
                 // The output type
-                (IsNonDecimalNumericOrIntegralEnumType g rty || isCharTy g rty) && 
-                // Exclusion: IntPtr and UIntPtr do not support .Parse() from string 
-                not (isStringTy g argty && isNativeIntegerTy g rty) &&
-                // Exclusion: No conversion from char to decimal
-                not (isCharTy g argty && isDecimalTy g rty)) -> 
+                (IsNonDecimalNumericOrIntegralEnumType g rty || isCharTy g rty)) -> 
 
           return TTraitBuiltIn
-
-
+          
+      // Conversions from (including decimal) numbers / strings / chars to decimals are built-in
       | _, _, false, "op_Explicit", [argty] 
           when (// The input type. 
-                (IsNumericOrIntegralEnumType g argty || isStringTy g argty) &&
+                (IsNumericOrIntegralEnumType g argty || isStringTy g argty || isCharTy g argty) &&
                 // The output type
                 (isDecimalTy g rty)) -> 
-
+          return TTraitBuiltIn
+
+      // Conversions from decimal numbers to native integers are built-in
+      // The rest of decimal conversions are handled via op_Explicit lookup on System.Decimal (which also looks for op_Implicit)
+      | _, _, false, "op_Explicit", [argty] 
+          when (// The input type. 
+                (isDecimalTy g argty) &&
+                // The output type
+                (isNativeIntegerTy g rty)) -> 
           return TTraitBuiltIn
 
       | [], _, false, "Pow", [argty1; argty2] 

src/fsharp/FSharp.Core/Linq.fsi

@@ -87,4 +87,4 @@ module LeafExpressionConverter =
     /// <example-tbd></example-tbd>
     val SubstHelperRaw: Expr * Var[] * obj[] -> Expr
 
-    val internal (|SpecificCallToMethod|_|): System.RuntimeMethodHandle -> (Expr -> (Expr option * Type list * Expr list) option)
+    val internal (|SpecificCallToMethod|_|): System.RuntimeMethodHandle -> (Expr -> (Expr option * Reflection.MethodInfo * Expr list) option)

src/fsharp/FSharp.Core/Query.fs

@@ -314,26 +314,27 @@ module Query =
         match prop.GetGetMethod true with
         | null -> None
         | v -> Some v
+    let (|GenericArgs|) (minfo: MethodInfo) = minfo.GetGenericArguments() |> Array.toList
 
     // Match 'f x'
     let (|SpecificCall1|_|) q =
        let (|CallQ|_|) = (|SpecificCallToMethod|_|) q
        function
-       | CallQ (Some builderObj, tyargs, [arg1]) -> Some(builderObj, tyargs, arg1)
+       | CallQ (Some builderObj, GenericArgs tyargs, [arg1]) -> Some(builderObj, tyargs, arg1)
        | _ -> None
 
     // Match 'f x y' or 'f (x, y)'
     let (|SpecificCall2|_|) q =
        let (|CallQ|_|) = (|SpecificCallToMethod|_|) q
        function
-       | CallQ (Some builderObj, tyargs, [arg1; arg2]) -> Some(builderObj, tyargs, arg1, arg2)
+       | CallQ (Some builderObj, GenericArgs tyargs, [arg1; arg2]) -> Some(builderObj, tyargs, arg1, arg2)
        | _ -> None
 
     // Match 'f x y z' or 'f (x, y, z)'
     let (|SpecificCall3|_|) q =
        let (|CallQ|_|) = (|SpecificCallToMethod|_|) q
        function
-       | CallQ (Some builderObj, tyargs, [arg1; arg2; arg3]) -> Some(builderObj, tyargs, arg1, arg2, arg3)
+       | CallQ (Some builderObj, GenericArgs tyargs, [arg1; arg2; arg3]) -> Some(builderObj, tyargs, arg1, arg2, arg3)
        | _ -> None
 
     /// (fun (x, y) -> z) is represented as 'fun p -> let x = p#0 let y = p#1' etc.
@@ -1286,7 +1287,7 @@ module Query =
         // rewrite has had the custom operator translation mechanism applied. In this case, the
         // body of the "for" will simply contain "yield".
 
-        | CallQueryBuilderFor (_, [_; qTy; immutResElemTy; _], [immutSource; Lambda(immutSelectorVar, immutSelector) ]) ->
+        | CallQueryBuilderFor (_, GenericArgs [_; qTy; immutResElemTy; _], [immutSource; Lambda(immutSelectorVar, immutSelector) ]) ->
 
             let mutSource, sourceConv = TransInner CanEliminate.Yes check immutSource
 
@@ -1467,7 +1468,7 @@ module Query =
                 | _ -> GroupingConv (immutKeySelector.Type, immutElementSelector.Type, selectorConv)
             TransInnerResult.Other(MakeGroupValBy(qTyIsIQueryable qTy, mutVar1.Type, mutKeySelector.Type, mutElementSelector.Type, mutSource, mutVar2, mutKeySelector, mutVar1, mutElementSelector)), conv
 
-        | CallJoin(_, [_; qTy; _; _; _],
+        | CallJoin(_, GenericArgs [_; qTy; _; _; _],
                    [ immutOuterSource
                      immutInnerSource
                      Lambda(immutOuterKeyVar, immutOuterKeySelector)
@@ -1491,7 +1492,7 @@ module Query =
             TransInnerResult.Other joinExpr, elementSelectorConv
 
         | CallGroupJoin
-              (_, [_; qTy; _; _; _], 
+              (_, GenericArgs [_; qTy; _; _; _], 
                [ immutOuterSource
                  immutInnerSource
                  Lambda(immutOuterKeyVar, immutOuterKeySelector)
@@ -1517,7 +1518,7 @@ module Query =
             TransInnerResult.Other joinExpr, elementSelectorConv
 
         | CallLeftOuterJoin
-             (_, [ _; qTy; immutInnerSourceTy; _; _],
+             (_, GenericArgs [ _; qTy; immutInnerSourceTy; _; _],
               [ immutOuterSource
                 immutInnerSource
                 Lambda(immutOuterKeyVar, immutOuterKeySelector)

src/fsharp/FSharp.Core/fslib-extra-pervasives.fs

@@ -378,5 +378,4 @@ namespace Microsoft.FSharp.Core.CompilerServices
 
     type ITypeProvider2 =
         abstract GetStaticParametersForMethod : methodWithoutArguments:MethodBase -> ParameterInfo[] 
-        abstract ApplyStaticArgumentsForMethod : methodWithoutArguments:MethodBase * methodNameWithArguments:string * staticArguments:obj[] -> MethodBase
-
+        abstract ApplyStaticArgumentsForMethod : methodWithoutArguments:MethodBase * methodNameWithArguments:string * staticArguments:obj[] -> MethodBase