1 files changed, 31 insertions, 0 deletions

diff --git a/vendor/github.com/zclconf/go-cty/cty/function/unpredictable.go b/vendor/github.com/zclconf/go-cty/cty/function/unpredictable.go
new file mode 100644
index 0000000..3495550
--- /dev/null
+++ b/vendor/github.com/zclconf/go-cty/cty/function/unpredictable.go
@@ -0,0 +1,31 @@
+package function
+
+import (
+        "github.com/zclconf/go-cty/cty"
+)
+
+// Unpredictable wraps a given function such that it retains the same arguments
+// and type checking behavior but will return an unknown value when called.
+//
+// It is recommended that most functions be "pure", which is to say that they
+// will always produce the same value given particular input. However,
+// sometimes it is necessary to offer functions whose behavior depends on
+// some external state, such as reading a file or determining the current time.
+// In such cases, an unpredictable wrapper might be used to stand in for
+// the function during some sort of prior "checking" phase in order to delay
+// the actual effect until later.
+//
+// While Unpredictable can support a function that isn't pure in its
+// implementation, it still expects a function to be pure in its type checking
+// behavior, except for the special case of returning cty.DynamicPseudoType
+// if it is not yet able to predict its return value based on current argument
+// information.
+func Unpredictable(f Function) Function {
+        newSpec := *f.spec // shallow copy
+        newSpec.Impl = unpredictableImpl
+        return New(&newSpec)
+}
+
+func unpredictableImpl(args []cty.Value, retType cty.Type) (cty.Value, error) {
+        return cty.UnknownVal(retType), nil
+}