terraform/vendor/github.com/zclconf/go-cty/cty/function/argument.go

71 lines
3.2 KiB
Go

package function
import (
"github.com/zclconf/go-cty/cty"
)
// Parameter represents a parameter to a function.
type Parameter struct {
// Name is an optional name for the argument. This package ignores this
// value, but callers may use it for documentation, etc.
Name string
// A type that any argument for this parameter must conform to.
// cty.DynamicPseudoType can be used, either at top-level or nested
// in a parameterized type, to indicate that any type should be
// permitted, to allow the definition of type-generic functions.
Type cty.Type
// If AllowNull is set then null values may be passed into this
// argument's slot in both the type-check function and the implementation
// function. If not set, such values are rejected by the built-in
// checking rules.
AllowNull bool
// If AllowUnknown is set then unknown values may be passed into this
// argument's slot in the implementation function. If not set, any
// unknown values will cause the function to immediately return
// an unkonwn value without calling the implementation function, thus
// freeing the function implementer from dealing with this case.
AllowUnknown bool
// If AllowDynamicType is set then DynamicVal may be passed into this
// argument's slot in the implementation function. If not set, any
// dynamic values will cause the function to immediately return
// DynamicVal value without calling the implementation function, thus
// freeing the function implementer from dealing with this case.
//
// Note that DynamicVal is also unknown, so in order to receive dynamic
// *values* it is also necessary to set AllowUnknown.
//
// However, it is valid to set AllowDynamicType without AllowUnknown, in
// which case a dynamic value may be passed to the type checking function
// but will not make it to the *implementation* function. Instead, an
// unknown value of the type returned by the type-check function will be
// returned. This is suggested for functions that have a static return
// type since it allows the return value to be typed even if the input
// values are not, thus improving the type-check accuracy of derived
// values.
AllowDynamicType bool
// If AllowMarked is set then marked values may be passed into this
// argument's slot in the implementation function. If not set, any
// marked value will be unmarked before calling and then the markings
// from that value will be applied automatically to the function result,
// ensuring that the marks get propagated in a simplistic way even if
// a function is unable to handle them.
//
// For any argument whose parameter has AllowMarked set, it's the
// function implementation's responsibility to Unmark the given value
// and propagate the marks appropriatedly to the result in order to
// avoid losing the marks. Application-specific functions might use
// special rules to selectively propagate particular marks.
//
// The automatic unmarking of values applies only to the main
// implementation function. In an application that uses marked values,
// the Type implementation for a function must always be prepared to accept
// marked values, which is easy to achieve by consulting only the type
// and ignoring the value itself.
AllowMarked bool
}