From 15c0b25d011f37e7c20aeca9eaf461f78285b8d9 Mon Sep 17 00:00:00 2001 From: Alex Pilon Date: Fri, 22 Feb 2019 18:24:37 -0500 Subject: deps: github.com/hashicorp/terraform@sdk-v0.11-with-go-modules Updated via: go get github.com/hashicorp/terraform@sdk-v0.11-with-go-modules and go mod tidy --- .../zclconf/go-cty/cty/function/function.go | 291 +++++++++++++++++++++ 1 file changed, 291 insertions(+) create mode 100644 vendor/github.com/zclconf/go-cty/cty/function/function.go (limited to 'vendor/github.com/zclconf/go-cty/cty/function/function.go') diff --git a/vendor/github.com/zclconf/go-cty/cty/function/function.go b/vendor/github.com/zclconf/go-cty/cty/function/function.go new file mode 100644 index 0000000..162f7bf --- /dev/null +++ b/vendor/github.com/zclconf/go-cty/cty/function/function.go @@ -0,0 +1,291 @@ +package function + +import ( + "fmt" + + "github.com/zclconf/go-cty/cty" +) + +// Function represents a function. This is the main type in this package. +type Function struct { + spec *Spec +} + +// Spec is the specification of a function, used to instantiate +// a new Function. +type Spec struct { + // Params is a description of the positional parameters for the function. + // The standard checking logic rejects any calls that do not provide + // arguments conforming to this definition, freeing the function + // implementer from dealing with such inconsistencies. + Params []Parameter + + // VarParam is an optional specification of additional "varargs" the + // function accepts. If this is non-nil then callers may provide an + // arbitrary number of additional arguments (after those matching with + // the fixed parameters in Params) that conform to the given specification, + // which will appear as additional values in the slices of values + // provided to the type and implementation functions. + VarParam *Parameter + + // Type is the TypeFunc that decides the return type of the function + // given its arguments, which may be Unknown. See the documentation + // of TypeFunc for more information. + // + // Use StaticReturnType if the function's return type does not vary + // depending on its arguments. + Type TypeFunc + + // Impl is the ImplFunc that implements the function's behavior. + // + // Functions are expected to behave as pure functions, and not create + // any visible side-effects. + // + // If a TypeFunc is also provided, the value returned from Impl *must* + // conform to the type it returns, or a call to the function will panic. + Impl ImplFunc +} + +// New creates a new function with the given specification. +// +// After passing a Spec to this function, the caller must no longer read from +// or mutate it. +func New(spec *Spec) Function { + f := Function{ + spec: spec, + } + return f +} + +// TypeFunc is a callback type for determining the return type of a function +// given its arguments. +// +// Any of the values passed to this function may be unknown, even if the +// parameters are not configured to accept unknowns. +// +// If any of the given values are *not* unknown, the TypeFunc may use the +// values for pre-validation and for choosing the return type. For example, +// a hypothetical JSON-unmarshalling function could return +// cty.DynamicPseudoType if the given JSON string is unknown, but return +// a concrete type based on the JSON structure if the JSON string is already +// known. +type TypeFunc func(args []cty.Value) (cty.Type, error) + +// ImplFunc is a callback type for the main implementation of a function. +// +// "args" are the values for the arguments, and this slice will always be at +// least as long as the argument definition slice for the function. +// +// "retType" is the type returned from the Type callback, included as a +// convenience to avoid the need to re-compute the return type for generic +// functions whose return type is a function of the arguments. +type ImplFunc func(args []cty.Value, retType cty.Type) (cty.Value, error) + +// StaticReturnType returns a TypeFunc that always returns the given type. +// +// This is provided as a convenience for defining a function whose return +// type does not depend on the argument types. +func StaticReturnType(ty cty.Type) TypeFunc { + return func([]cty.Value) (cty.Type, error) { + return ty, nil + } +} + +// ReturnType returns the return type of a function given a set of candidate +// argument types, or returns an error if the given types are unacceptable. +// +// If the caller already knows values for at least some of the arguments +// it can be better to call ReturnTypeForValues, since certain functions may +// determine their return types from their values and return DynamicVal if +// the values are unknown. +func (f Function) ReturnType(argTypes []cty.Type) (cty.Type, error) { + vals := make([]cty.Value, len(argTypes)) + for i, ty := range argTypes { + vals[i] = cty.UnknownVal(ty) + } + return f.ReturnTypeForValues(vals) +} + +// ReturnTypeForValues is similar to ReturnType but can be used if the caller +// already knows the values of some or all of the arguments, in which case +// the function may be able to determine a more definite result if its +// return type depends on the argument *values*. +// +// For any arguments whose values are not known, pass an Unknown value of +// the appropriate type. +func (f Function) ReturnTypeForValues(args []cty.Value) (ty cty.Type, err error) { + var posArgs []cty.Value + var varArgs []cty.Value + + if f.spec.VarParam == nil { + if len(args) != len(f.spec.Params) { + return cty.Type{}, fmt.Errorf( + "wrong number of arguments (%d required; %d given)", + len(f.spec.Params), len(args), + ) + } + + posArgs = args + varArgs = nil + } else { + if len(args) < len(f.spec.Params) { + return cty.Type{}, fmt.Errorf( + "wrong number of arguments (at least %d required; %d given)", + len(f.spec.Params), len(args), + ) + } + + posArgs = args[0:len(f.spec.Params)] + varArgs = args[len(f.spec.Params):] + } + + for i, spec := range f.spec.Params { + val := posArgs[i] + + if val.IsNull() && !spec.AllowNull { + return cty.Type{}, NewArgErrorf(i, "must not be null") + } + + // AllowUnknown is ignored for type-checking, since we expect to be + // able to type check with unknown values. We *do* still need to deal + // with DynamicPseudoType here though, since the Type function might + // not be ready to deal with that. + + if val.Type() == cty.DynamicPseudoType { + if !spec.AllowDynamicType { + return cty.DynamicPseudoType, nil + } + } else if errs := val.Type().TestConformance(spec.Type); errs != nil { + // For now we'll just return the first error in the set, since + // we don't have a good way to return the whole list here. + // Would be good to do something better at some point... + return cty.Type{}, NewArgError(i, errs[0]) + } + } + + if varArgs != nil { + spec := f.spec.VarParam + for i, val := range varArgs { + realI := i + len(posArgs) + + if val.IsNull() && !spec.AllowNull { + return cty.Type{}, NewArgErrorf(realI, "must not be null") + } + + if val.Type() == cty.DynamicPseudoType { + if !spec.AllowDynamicType { + return cty.DynamicPseudoType, nil + } + } else if errs := val.Type().TestConformance(spec.Type); errs != nil { + // For now we'll just return the first error in the set, since + // we don't have a good way to return the whole list here. + // Would be good to do something better at some point... + return cty.Type{}, NewArgError(i, errs[0]) + } + } + } + + // Intercept any panics from the function and return them as normal errors, + // so a calling language runtime doesn't need to deal with panics. + defer func() { + if r := recover(); r != nil { + ty = cty.NilType + err = errorForPanic(r) + } + }() + + return f.spec.Type(args) +} + +// Call actually calls the function with the given arguments, which must +// conform to the function's parameter specification or an error will be +// returned. +func (f Function) Call(args []cty.Value) (val cty.Value, err error) { + expectedType, err := f.ReturnTypeForValues(args) + if err != nil { + return cty.NilVal, err + } + + // Type checking already dealt with most situations relating to our + // parameter specification, but we still need to deal with unknown + // values. + posArgs := args[:len(f.spec.Params)] + varArgs := args[len(f.spec.Params):] + + for i, spec := range f.spec.Params { + val := posArgs[i] + + if !val.IsKnown() && !spec.AllowUnknown { + return cty.UnknownVal(expectedType), nil + } + } + + if f.spec.VarParam != nil { + spec := f.spec.VarParam + for _, val := range varArgs { + if !val.IsKnown() && !spec.AllowUnknown { + return cty.UnknownVal(expectedType), nil + } + } + } + + var retVal cty.Value + { + // Intercept any panics from the function and return them as normal errors, + // so a calling language runtime doesn't need to deal with panics. + defer func() { + if r := recover(); r != nil { + val = cty.NilVal + err = errorForPanic(r) + } + }() + + retVal, err = f.spec.Impl(args, expectedType) + if err != nil { + return cty.NilVal, err + } + } + + // Returned value must conform to what the Type function expected, to + // protect callers from having to deal with inconsistencies. + if errs := retVal.Type().TestConformance(expectedType); errs != nil { + panic(fmt.Errorf( + "returned value %#v does not conform to expected return type %#v: %s", + retVal, expectedType, errs[0], + )) + } + + return retVal, nil +} + +// ProxyFunc the type returned by the method Function.Proxy. +type ProxyFunc func(args ...cty.Value) (cty.Value, error) + +// Proxy returns a function that can be called with cty.Value arguments +// to run the function. This is provided as a convenience for when using +// a function directly within Go code. +func (f Function) Proxy() ProxyFunc { + return func(args ...cty.Value) (cty.Value, error) { + return f.Call(args) + } +} + +// Params returns information about the function's fixed positional parameters. +// This does not include information about any variadic arguments accepted; +// for that, call VarParam. +func (f Function) Params() []Parameter { + new := make([]Parameter, len(f.spec.Params)) + copy(new, f.spec.Params) + return new +} + +// VarParam returns information about the variadic arguments the function +// expects, or nil if the function is not variadic. +func (f Function) VarParam() *Parameter { + if f.spec.VarParam == nil { + return nil + } + + ret := *f.spec.VarParam + return &ret +} -- cgit v1.2.3