added

vendor/github.com/zclconf/go-cty/cty/function/stdlib/set.go

@@ -0,0 +1,232 @@
+package stdlib
+
+import (
+	"fmt"
+
+	"github.com/zclconf/go-cty/cty/convert"
+
+	"github.com/zclconf/go-cty/cty"
+	"github.com/zclconf/go-cty/cty/function"
+)
+
+var SetHasElementFunc = function.New(&function.Spec{
+	Description: `Returns true if the given set contains the given element, or false otherwise.`,
+	Params: []function.Parameter{
+		{
+			Name:             "set",
+			Type:             cty.Set(cty.DynamicPseudoType),
+			AllowDynamicType: true,
+		},
+		{
+			Name:             "elem",
+			Type:             cty.DynamicPseudoType,
+			AllowDynamicType: true,
+		},
+	},
+	Type:         function.StaticReturnType(cty.Bool),
+	RefineResult: refineNonNull,
+	Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
+		return args[0].HasElement(args[1]), nil
+	},
+})
+
+var SetUnionFunc = function.New(&function.Spec{
+	Description: `Returns the union of all given sets.`,
+	Params: []function.Parameter{
+		{
+			Name:             "first_set",
+			Type:             cty.Set(cty.DynamicPseudoType),
+			AllowDynamicType: true,
+		},
+	},
+	VarParam: &function.Parameter{
+		Name:             "other_sets",
+		Type:             cty.Set(cty.DynamicPseudoType),
+		AllowDynamicType: true,
+	},
+	Type:         setOperationReturnType,
+	RefineResult: refineNonNull,
+	Impl: setOperationImpl(func(s1, s2 cty.ValueSet) cty.ValueSet {
+		return s1.Union(s2)
+	}, true),
+})
+
+var SetIntersectionFunc = function.New(&function.Spec{
+	Description: `Returns the intersection of all given sets.`,
+	Params: []function.Parameter{
+		{
+			Name:             "first_set",
+			Type:             cty.Set(cty.DynamicPseudoType),
+			AllowDynamicType: true,
+		},
+	},
+	VarParam: &function.Parameter{
+		Name:             "other_sets",
+		Type:             cty.Set(cty.DynamicPseudoType),
+		AllowDynamicType: true,
+	},
+	Type:         setOperationReturnType,
+	RefineResult: refineNonNull,
+	Impl: setOperationImpl(func(s1, s2 cty.ValueSet) cty.ValueSet {
+		return s1.Intersection(s2)
+	}, false),
+})
+
+var SetSubtractFunc = function.New(&function.Spec{
+	Description: `Returns the relative complement of the two given sets.`,
+	Params: []function.Parameter{
+		{
+			Name:             "a",
+			Type:             cty.Set(cty.DynamicPseudoType),
+			AllowDynamicType: true,
+		},
+		{
+			Name:             "b",
+			Type:             cty.Set(cty.DynamicPseudoType),
+			AllowDynamicType: true,
+		},
+	},
+	Type:         setOperationReturnType,
+	RefineResult: refineNonNull,
+	Impl: setOperationImpl(func(s1, s2 cty.ValueSet) cty.ValueSet {
+		return s1.Subtract(s2)
+	}, false),
+})
+
+var SetSymmetricDifferenceFunc = function.New(&function.Spec{
+	Description: `Returns the symmetric difference of the two given sets.`,
+	Params: []function.Parameter{
+		{
+			Name:             "first_set",
+			Type:             cty.Set(cty.DynamicPseudoType),
+			AllowDynamicType: true,
+		},
+	},
+	VarParam: &function.Parameter{
+		Name:             "other_sets",
+		Type:             cty.Set(cty.DynamicPseudoType),
+		AllowDynamicType: true,
+	},
+	Type:         setOperationReturnType,
+	RefineResult: refineNonNull,
+	Impl: setOperationImpl(func(s1, s2 cty.ValueSet) cty.ValueSet {
+		return s1.SymmetricDifference(s2)
+	}, false),
+})
+
+// SetHasElement determines whether the given set contains the given value as an
+// element.
+func SetHasElement(set cty.Value, elem cty.Value) (cty.Value, error) {
+	return SetHasElementFunc.Call([]cty.Value{set, elem})
+}
+
+// SetUnion returns a new set containing all of the elements from the given
+// sets, which must have element types that can all be converted to some
+// common type using the standard type unification rules. If conversion
+// is not possible, an error is returned.
+//
+// The union operation is performed after type conversion, which may result
+// in some previously-distinct values being conflated.
+//
+// At least one set must be provided.
+func SetUnion(sets ...cty.Value) (cty.Value, error) {
+	return SetUnionFunc.Call(sets)
+}
+
+// Intersection returns a new set containing the elements that exist
+// in all of the given sets, which must have element types that can all be
+// converted to some common type using the standard type unification rules.
+// If conversion is not possible, an error is returned.
+//
+// The intersection operation is performed after type conversion, which may
+// result in some previously-distinct values being conflated.
+//
+// At least one set must be provided.
+func SetIntersection(sets ...cty.Value) (cty.Value, error) {
+	return SetIntersectionFunc.Call(sets)
+}
+
+// SetSubtract returns a new set containing the elements from the
+// first set that are not present in the second set. The sets must have
+// element types that can both be converted to some common type using the
+// standard type unification rules. If conversion is not possible, an error
+// is returned.
+//
+// The subtract operation is performed after type conversion, which may
+// result in some previously-distinct values being conflated.
+func SetSubtract(a, b cty.Value) (cty.Value, error) {
+	return SetSubtractFunc.Call([]cty.Value{a, b})
+}
+
+// SetSymmetricDifference returns a new set containing elements that appear
+// in any of the given sets but not multiple. The sets must have
+// element types that can all be converted to some common type using the
+// standard type unification rules. If conversion is not possible, an error
+// is returned.
+//
+// The difference operation is performed after type conversion, which may
+// result in some previously-distinct values being conflated.
+func SetSymmetricDifference(sets ...cty.Value) (cty.Value, error) {
+	return SetSymmetricDifferenceFunc.Call(sets)
+}
+
+func setOperationReturnType(args []cty.Value) (ret cty.Type, err error) {
+	var etys []cty.Type
+	for _, arg := range args {
+		ty := arg.Type().ElementType()
+
+		// Do not unify types for empty dynamic pseudo typed collections. These
+		// will always convert to any other concrete type.
+		if arg.IsKnown() && arg.LengthInt() == 0 && ty.Equals(cty.DynamicPseudoType) {
+			continue
+		}
+
+		etys = append(etys, ty)
+	}
+
+	// If all element types were skipped (due to being empty dynamic collections),
+	// the return type should also be a set of dynamic pseudo type.
+	if len(etys) == 0 {
+		return cty.Set(cty.DynamicPseudoType), nil
+	}
+
+	newEty, _ := convert.UnifyUnsafe(etys)
+	if newEty == cty.NilType {
+		return cty.NilType, fmt.Errorf("given sets must all have compatible element types")
+	}
+	return cty.Set(newEty), nil
+}
+
+func setOperationImpl(f func(s1, s2 cty.ValueSet) cty.ValueSet, allowUnknowns bool) function.ImplFunc {
+	return func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
+		first := args[0]
+		first, err = convert.Convert(first, retType)
+		if err != nil {
+			return cty.NilVal, function.NewArgError(0, err)
+		}
+		if !allowUnknowns && !first.IsWhollyKnown() {
+			// This set function can produce a correct result only when all
+			// elements are known, because eventually knowing the unknown
+			// values may cause the result to have fewer known elements, or
+			// might cause a result with no unknown elements at all to become
+			// one with a different length.
+			return cty.UnknownVal(retType), nil
+		}
+
+		set := first.AsValueSet()
+		for i, arg := range args[1:] {
+			arg, err := convert.Convert(arg, retType)
+			if err != nil {
+				return cty.NilVal, function.NewArgError(i+1, err)
+			}
+			if !allowUnknowns && !arg.IsWhollyKnown() {
+				// (For the same reason as we did this check for "first" above.)
+				return cty.UnknownVal(retType), nil
+			}
+
+			argSet := arg.AsValueSet()
+			set = f(set, argSet)
+		}
+		return cty.SetValFromValueSet(set), nil
+	}
+}