terraform/lang/funcs/collection.go

1520 lines
43 KiB
Go

package funcs
import (
"errors"
"fmt"
"sort"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/convert"
"github.com/zclconf/go-cty/cty/function"
"github.com/zclconf/go-cty/cty/function/stdlib"
"github.com/zclconf/go-cty/cty/gocty"
)
var ElementFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.DynamicPseudoType,
},
{
Name: "index",
Type: cty.Number,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
list := args[0]
listTy := list.Type()
switch {
case listTy.IsListType():
return listTy.ElementType(), nil
case listTy.IsTupleType():
if !args[1].IsKnown() {
// If the index isn't known yet then we can't predict the
// result type since each tuple element can have its own type.
return cty.DynamicPseudoType, nil
}
etys := listTy.TupleElementTypes()
var index int
err := gocty.FromCtyValue(args[1], &index)
if err != nil {
// e.g. fractional number where whole number is required
return cty.DynamicPseudoType, fmt.Errorf("invalid index: %s", err)
}
if len(etys) == 0 {
return cty.DynamicPseudoType, errors.New("cannot use element function with an empty list")
}
index = index % len(etys)
return etys[index], nil
default:
return cty.DynamicPseudoType, fmt.Errorf("cannot read elements from %s", listTy.FriendlyName())
}
},
Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) {
var index int
err := gocty.FromCtyValue(args[1], &index)
if err != nil {
// can't happen because we checked this in the Type function above
return cty.DynamicVal, fmt.Errorf("invalid index: %s", err)
}
if !args[0].IsKnown() {
return cty.UnknownVal(retType), nil
}
l := args[0].LengthInt()
if l == 0 {
return cty.DynamicVal, errors.New("cannot use element function with an empty list")
}
index = index % l
// We did all the necessary type checks in the type function above,
// so this is guaranteed not to fail.
return args[0].Index(cty.NumberIntVal(int64(index))), nil
},
})
var LengthFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "value",
Type: cty.DynamicPseudoType,
AllowDynamicType: true,
AllowUnknown: true,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
collTy := args[0].Type()
switch {
case collTy == cty.String || collTy.IsTupleType() || collTy.IsObjectType() || collTy.IsListType() || collTy.IsMapType() || collTy.IsSetType() || collTy == cty.DynamicPseudoType:
return cty.Number, nil
default:
return cty.Number, errors.New("argument must be a string, a collection type, or a structural type")
}
},
Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) {
coll := args[0]
collTy := args[0].Type()
switch {
case collTy == cty.DynamicPseudoType:
return cty.UnknownVal(cty.Number), nil
case collTy.IsTupleType():
l := len(collTy.TupleElementTypes())
return cty.NumberIntVal(int64(l)), nil
case collTy.IsObjectType():
l := len(collTy.AttributeTypes())
return cty.NumberIntVal(int64(l)), nil
case collTy == cty.String:
// We'll delegate to the cty stdlib strlen function here, because
// it deals with all of the complexities of tokenizing unicode
// grapheme clusters.
return stdlib.Strlen(coll)
case collTy.IsListType() || collTy.IsSetType() || collTy.IsMapType():
return coll.Length(), nil
default:
// Should never happen, because of the checks in our Type func above
return cty.UnknownVal(cty.Number), errors.New("impossible value type for length(...)")
}
},
})
// CoalesceFunc constructs a function that takes any number of arguments and
// returns the first one that isn't empty. This function was copied from go-cty
// stdlib and modified so that it returns the first *non-empty* non-null element
// from a sequence, instead of merely the first non-null.
var CoalesceFunc = function.New(&function.Spec{
Params: []function.Parameter{},
VarParam: &function.Parameter{
Name: "vals",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
AllowDynamicType: true,
AllowNull: true,
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
argTypes := make([]cty.Type, len(args))
for i, val := range args {
argTypes[i] = val.Type()
}
retType, _ := convert.UnifyUnsafe(argTypes)
if retType == cty.NilType {
return cty.NilType, errors.New("all arguments must have the same type")
}
return retType, nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
for _, argVal := range args {
// We already know this will succeed because of the checks in our Type func above
argVal, _ = convert.Convert(argVal, retType)
if !argVal.IsKnown() {
return cty.UnknownVal(retType), nil
}
if argVal.IsNull() {
continue
}
if retType == cty.String && argVal.RawEquals(cty.StringVal("")) {
continue
}
return argVal, nil
}
return cty.NilVal, errors.New("no non-null, non-empty-string arguments")
},
})
// CoalesceListFunc constructs a function that takes any number of list arguments
// and returns the first one that isn't empty.
var CoalesceListFunc = function.New(&function.Spec{
Params: []function.Parameter{},
VarParam: &function.Parameter{
Name: "vals",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
AllowDynamicType: true,
AllowNull: true,
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
if len(args) == 0 {
return cty.NilType, errors.New("at least one argument is required")
}
argTypes := make([]cty.Type, len(args))
for i, arg := range args {
// if any argument is unknown, we can't be certain know which type we will return
if !arg.IsKnown() {
return cty.DynamicPseudoType, nil
}
ty := arg.Type()
if !ty.IsListType() && !ty.IsTupleType() {
return cty.NilType, errors.New("coalescelist arguments must be lists or tuples")
}
argTypes[i] = arg.Type()
}
last := argTypes[0]
// If there are mixed types, we have to return a dynamic type.
for _, next := range argTypes[1:] {
if !next.Equals(last) {
return cty.DynamicPseudoType, nil
}
}
return last, nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
for _, arg := range args {
if !arg.IsKnown() {
// If we run into an unknown list at some point, we can't
// predict the final result yet. (If there's a known, non-empty
// arg before this then we won't get here.)
return cty.UnknownVal(retType), nil
}
if arg.LengthInt() > 0 {
return arg, nil
}
}
return cty.NilVal, errors.New("no non-null arguments")
},
})
// CompactFunc constructs a function that takes a list of strings and returns a new list
// with any empty string elements removed.
var CompactFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.List(cty.String),
},
},
Type: function.StaticReturnType(cty.List(cty.String)),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
listVal := args[0]
if !listVal.IsWhollyKnown() {
// If some of the element values aren't known yet then we
// can't yet return a compacted list
return cty.UnknownVal(retType), nil
}
var outputList []cty.Value
for it := listVal.ElementIterator(); it.Next(); {
_, v := it.Element()
if v.IsNull() || v.AsString() == "" {
continue
}
outputList = append(outputList, v)
}
if len(outputList) == 0 {
return cty.ListValEmpty(cty.String), nil
}
return cty.ListVal(outputList), nil
},
})
// ContainsFunc constructs a function that determines whether a given list or
// set contains a given single value as one of its elements.
var ContainsFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.DynamicPseudoType,
},
{
Name: "value",
Type: cty.DynamicPseudoType,
},
},
Type: function.StaticReturnType(cty.Bool),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
arg := args[0]
ty := arg.Type()
if !ty.IsListType() && !ty.IsTupleType() && !ty.IsSetType() {
return cty.NilVal, errors.New("argument must be list, tuple, or set")
}
_, err = Index(cty.TupleVal(arg.AsValueSlice()), args[1])
if err != nil {
return cty.False, nil
}
return cty.True, nil
},
})
// IndexFunc constructs a function that finds the element index for a given value in a list.
var IndexFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.DynamicPseudoType,
},
{
Name: "value",
Type: cty.DynamicPseudoType,
},
},
Type: function.StaticReturnType(cty.Number),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
if !(args[0].Type().IsListType() || args[0].Type().IsTupleType()) {
return cty.NilVal, errors.New("argument must be a list or tuple")
}
if !args[0].IsKnown() {
return cty.UnknownVal(cty.Number), nil
}
if args[0].LengthInt() == 0 { // Easy path
return cty.NilVal, errors.New("cannot search an empty list")
}
for it := args[0].ElementIterator(); it.Next(); {
i, v := it.Element()
eq, err := stdlib.Equal(v, args[1])
if err != nil {
return cty.NilVal, err
}
if !eq.IsKnown() {
return cty.UnknownVal(cty.Number), nil
}
if eq.True() {
return i, nil
}
}
return cty.NilVal, errors.New("item not found")
},
})
// DistinctFunc constructs a function that takes a list and returns a new list
// with any duplicate elements removed.
var DistinctFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.List(cty.DynamicPseudoType),
},
},
Type: func(args []cty.Value) (cty.Type, error) {
return args[0].Type(), nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
listVal := args[0]
if !listVal.IsWhollyKnown() {
return cty.UnknownVal(retType), nil
}
var list []cty.Value
for it := listVal.ElementIterator(); it.Next(); {
_, v := it.Element()
list, err = appendIfMissing(list, v)
if err != nil {
return cty.NilVal, err
}
}
if len(list) == 0 {
return cty.ListValEmpty(retType.ElementType()), nil
}
return cty.ListVal(list), nil
},
})
// ChunklistFunc constructs a function that splits a single list into fixed-size chunks,
// returning a list of lists.
var ChunklistFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.List(cty.DynamicPseudoType),
},
{
Name: "size",
Type: cty.Number,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
return cty.List(args[0].Type()), nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
listVal := args[0]
if !listVal.IsKnown() {
return cty.UnknownVal(retType), nil
}
if listVal.LengthInt() == 0 {
return cty.ListValEmpty(listVal.Type()), nil
}
var size int
err = gocty.FromCtyValue(args[1], &size)
if err != nil {
return cty.NilVal, fmt.Errorf("invalid index: %s", err)
}
if size < 0 {
return cty.NilVal, errors.New("the size argument must be positive")
}
output := make([]cty.Value, 0)
// if size is 0, returns a list made of the initial list
if size == 0 {
output = append(output, listVal)
return cty.ListVal(output), nil
}
chunk := make([]cty.Value, 0)
l := args[0].LengthInt()
i := 0
for it := listVal.ElementIterator(); it.Next(); {
_, v := it.Element()
chunk = append(chunk, v)
// Chunk when index isn't 0, or when reaching the values's length
if (i+1)%size == 0 || (i+1) == l {
output = append(output, cty.ListVal(chunk))
chunk = make([]cty.Value, 0)
}
i++
}
return cty.ListVal(output), nil
},
})
// FlattenFunc constructs a function that takes a list and replaces any elements
// that are lists with a flattened sequence of the list contents.
var FlattenFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.DynamicPseudoType,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
if !args[0].IsWhollyKnown() {
return cty.DynamicPseudoType, nil
}
argTy := args[0].Type()
if !argTy.IsListType() && !argTy.IsSetType() && !argTy.IsTupleType() {
return cty.NilType, errors.New("can only flatten lists, sets and tuples")
}
retVal, known := flattener(args[0])
if !known {
return cty.DynamicPseudoType, nil
}
tys := make([]cty.Type, len(retVal))
for i, ty := range retVal {
tys[i] = ty.Type()
}
return cty.Tuple(tys), nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
inputList := args[0]
if inputList.LengthInt() == 0 {
return cty.EmptyTupleVal, nil
}
out, known := flattener(inputList)
if !known {
return cty.UnknownVal(retType), nil
}
return cty.TupleVal(out), nil
},
})
// Flatten until it's not a cty.List, and return whether the value is known.
// We can flatten lists with unknown values, as long as they are not
// lists themselves.
func flattener(flattenList cty.Value) ([]cty.Value, bool) {
out := make([]cty.Value, 0)
for it := flattenList.ElementIterator(); it.Next(); {
_, val := it.Element()
if val.Type().IsListType() || val.Type().IsSetType() || val.Type().IsTupleType() {
if !val.IsKnown() {
return out, false
}
res, known := flattener(val)
if !known {
return res, known
}
out = append(out, res...)
} else {
out = append(out, val)
}
}
return out, true
}
// KeysFunc constructs a function that takes a map and returns a sorted list of the map keys.
var KeysFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "inputMap",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
ty := args[0].Type()
switch {
case ty.IsMapType():
return cty.List(cty.String), nil
case ty.IsObjectType():
atys := ty.AttributeTypes()
if len(atys) == 0 {
return cty.EmptyTuple, nil
}
// All of our result elements will be strings, and atys just
// decides how many there are.
etys := make([]cty.Type, len(atys))
for i := range etys {
etys[i] = cty.String
}
return cty.Tuple(etys), nil
default:
return cty.DynamicPseudoType, function.NewArgErrorf(0, "must have map or object type")
}
},
Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) {
m := args[0]
var keys []cty.Value
switch {
case m.Type().IsObjectType():
// In this case we allow unknown values so we must work only with
// the attribute _types_, not with the value itself.
var names []string
for name := range m.Type().AttributeTypes() {
names = append(names, name)
}
sort.Strings(names) // same ordering guaranteed by cty's ElementIterator
if len(names) == 0 {
return cty.EmptyTupleVal, nil
}
keys = make([]cty.Value, len(names))
for i, name := range names {
keys[i] = cty.StringVal(name)
}
return cty.TupleVal(keys), nil
default:
if !m.IsKnown() {
return cty.UnknownVal(retType), nil
}
// cty guarantees that ElementIterator will iterate in lexicographical
// order by key.
for it := args[0].ElementIterator(); it.Next(); {
k, _ := it.Element()
keys = append(keys, k)
}
if len(keys) == 0 {
return cty.ListValEmpty(cty.String), nil
}
return cty.ListVal(keys), nil
}
},
})
// ListFunc constructs a function that takes an arbitrary number of arguments
// and returns a list containing those values in the same order.
//
// This function is deprecated in Terraform v0.12
var ListFunc = function.New(&function.Spec{
Params: []function.Parameter{},
VarParam: &function.Parameter{
Name: "vals",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
AllowDynamicType: true,
AllowNull: true,
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
if len(args) == 0 {
return cty.NilType, errors.New("at least one argument is required")
}
argTypes := make([]cty.Type, len(args))
for i, arg := range args {
argTypes[i] = arg.Type()
}
retType, _ := convert.UnifyUnsafe(argTypes)
if retType == cty.NilType {
return cty.NilType, errors.New("all arguments must have the same type")
}
return cty.List(retType), nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
newList := make([]cty.Value, 0, len(args))
for _, arg := range args {
// We already know this will succeed because of the checks in our Type func above
arg, _ = convert.Convert(arg, retType.ElementType())
newList = append(newList, arg)
}
return cty.ListVal(newList), nil
},
})
// LookupFunc constructs a function that performs dynamic lookups of map types.
var LookupFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "inputMap",
Type: cty.DynamicPseudoType,
},
{
Name: "key",
Type: cty.String,
},
},
VarParam: &function.Parameter{
Name: "default",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
AllowDynamicType: true,
AllowNull: true,
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
if len(args) < 1 || len(args) > 3 {
return cty.NilType, fmt.Errorf("lookup() takes two or three arguments, got %d", len(args))
}
ty := args[0].Type()
switch {
case ty.IsObjectType():
if !args[1].IsKnown() {
return cty.DynamicPseudoType, nil
}
key := args[1].AsString()
if ty.HasAttribute(key) {
return args[0].GetAttr(key).Type(), nil
} else if len(args) == 3 {
// if the key isn't found but a default is provided,
// return the default type
return args[2].Type(), nil
}
return cty.DynamicPseudoType, function.NewArgErrorf(0, "the given object has no attribute %q", key)
case ty.IsMapType():
if len(args) == 3 {
_, err = convert.Convert(args[2], ty.ElementType())
if err != nil {
return cty.NilType, function.NewArgErrorf(2, "the default value must have the same type as the map elements")
}
}
return ty.ElementType(), nil
default:
return cty.NilType, function.NewArgErrorf(0, "lookup() requires a map as the first argument")
}
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
var defaultVal cty.Value
defaultValueSet := false
if len(args) == 3 {
defaultVal = args[2]
defaultValueSet = true
}
mapVar := args[0]
lookupKey := args[1].AsString()
if !mapVar.IsWhollyKnown() {
return cty.UnknownVal(retType), nil
}
if mapVar.Type().IsObjectType() {
if mapVar.Type().HasAttribute(lookupKey) {
return mapVar.GetAttr(lookupKey), nil
}
} else if mapVar.HasIndex(cty.StringVal(lookupKey)) == cty.True {
return mapVar.Index(cty.StringVal(lookupKey)), nil
}
if defaultValueSet {
defaultVal, err = convert.Convert(defaultVal, retType)
if err != nil {
return cty.NilVal, err
}
return defaultVal, nil
}
return cty.UnknownVal(cty.DynamicPseudoType), fmt.Errorf(
"lookup failed to find '%s'", lookupKey)
},
})
// MapFunc constructs a function that takes an even number of arguments and
// returns a map whose elements are constructed from consecutive pairs of arguments.
//
// This function is deprecated in Terraform v0.12
var MapFunc = function.New(&function.Spec{
Params: []function.Parameter{},
VarParam: &function.Parameter{
Name: "vals",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
AllowDynamicType: true,
AllowNull: true,
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
if len(args) < 2 || len(args)%2 != 0 {
return cty.NilType, fmt.Errorf("map requires an even number of two or more arguments, got %d", len(args))
}
argTypes := make([]cty.Type, len(args)/2)
index := 0
for i := 0; i < len(args); i += 2 {
argTypes[index] = args[i+1].Type()
index++
}
valType, _ := convert.UnifyUnsafe(argTypes)
if valType == cty.NilType {
return cty.NilType, errors.New("all arguments must have the same type")
}
return cty.Map(valType), nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
for _, arg := range args {
if !arg.IsWhollyKnown() {
return cty.UnknownVal(retType), nil
}
}
outputMap := make(map[string]cty.Value)
for i := 0; i < len(args); i += 2 {
key := args[i].AsString()
err := gocty.FromCtyValue(args[i], &key)
if err != nil {
return cty.NilVal, err
}
val := args[i+1]
var variable cty.Value
err = gocty.FromCtyValue(val, &variable)
if err != nil {
return cty.NilVal, err
}
// We already know this will succeed because of the checks in our Type func above
variable, _ = convert.Convert(variable, retType.ElementType())
// Check for duplicate keys
if _, ok := outputMap[key]; ok {
return cty.NilVal, fmt.Errorf("argument %d is a duplicate key: %q", i+1, key)
}
outputMap[key] = variable
}
return cty.MapVal(outputMap), nil
},
})
// MatchkeysFunc constructs a function that constructs a new list by taking a
// subset of elements from one list whose indexes match the corresponding
// indexes of values in another list.
var MatchkeysFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "values",
Type: cty.List(cty.DynamicPseudoType),
},
{
Name: "keys",
Type: cty.List(cty.DynamicPseudoType),
},
{
Name: "searchset",
Type: cty.List(cty.DynamicPseudoType),
},
},
Type: func(args []cty.Value) (cty.Type, error) {
ty, _ := convert.UnifyUnsafe([]cty.Type{args[1].Type(), args[2].Type()})
if ty == cty.NilType {
return cty.NilType, errors.New("keys and searchset must be of the same type")
}
// the return type is based on args[0] (values)
return args[0].Type(), nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
if !args[0].IsKnown() {
return cty.UnknownVal(cty.List(retType.ElementType())), nil
}
if args[0].LengthInt() != args[1].LengthInt() {
return cty.ListValEmpty(retType.ElementType()), errors.New("length of keys and values should be equal")
}
output := make([]cty.Value, 0)
values := args[0]
// Keys and searchset must be the same type.
// We can skip error checking here because we've already verified that
// they can be unified in the Type function
ty, _ := convert.UnifyUnsafe([]cty.Type{args[1].Type(), args[2].Type()})
keys, _ := convert.Convert(args[1], ty)
searchset, _ := convert.Convert(args[2], ty)
// if searchset is empty, return an empty list.
if searchset.LengthInt() == 0 {
return cty.ListValEmpty(retType.ElementType()), nil
}
if !values.IsWhollyKnown() || !keys.IsWhollyKnown() {
return cty.UnknownVal(retType), nil
}
i := 0
for it := keys.ElementIterator(); it.Next(); {
_, key := it.Element()
for iter := searchset.ElementIterator(); iter.Next(); {
_, search := iter.Element()
eq, err := stdlib.Equal(key, search)
if err != nil {
return cty.NilVal, err
}
if !eq.IsKnown() {
return cty.ListValEmpty(retType.ElementType()), nil
}
if eq.True() {
v := values.Index(cty.NumberIntVal(int64(i)))
output = append(output, v)
break
}
}
i++
}
// if we haven't matched any key, then output is an empty list.
if len(output) == 0 {
return cty.ListValEmpty(retType.ElementType()), nil
}
return cty.ListVal(output), nil
},
})
// MergeFunc constructs a function that takes an arbitrary number of maps and
// returns a single map that contains a merged set of elements from all of the maps.
//
// If more than one given map defines the same key then the one that is later in
// the argument sequence takes precedence.
var MergeFunc = function.New(&function.Spec{
Params: []function.Parameter{},
VarParam: &function.Parameter{
Name: "maps",
Type: cty.DynamicPseudoType,
AllowDynamicType: true,
},
Type: function.StaticReturnType(cty.DynamicPseudoType),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
outputMap := make(map[string]cty.Value)
for _, arg := range args {
if !arg.IsWhollyKnown() {
return cty.UnknownVal(retType), nil
}
if !arg.Type().IsObjectType() && !arg.Type().IsMapType() {
return cty.NilVal, fmt.Errorf("arguments must be maps or objects, got %#v", arg.Type().FriendlyName())
}
for it := arg.ElementIterator(); it.Next(); {
k, v := it.Element()
outputMap[k.AsString()] = v
}
}
return cty.ObjectVal(outputMap), nil
},
})
// ReverseFunc takes a sequence and produces a new sequence of the same length
// with all of the same elements as the given sequence but in reverse order.
var ReverseFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.DynamicPseudoType,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
argTy := args[0].Type()
switch {
case argTy.IsTupleType():
argTys := argTy.TupleElementTypes()
retTys := make([]cty.Type, len(argTys))
for i, ty := range argTys {
retTys[len(retTys)-i-1] = ty
}
return cty.Tuple(retTys), nil
case argTy.IsListType(), argTy.IsSetType(): // We accept sets here to mimic the usual behavior of auto-converting to list
return cty.List(argTy.ElementType()), nil
default:
return cty.NilType, function.NewArgErrorf(0, "can only reverse list or tuple values, not %s", argTy.FriendlyName())
}
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
in := args[0].AsValueSlice()
outVals := make([]cty.Value, len(in))
for i, v := range in {
outVals[len(outVals)-i-1] = v
}
switch {
case retType.IsTupleType():
return cty.TupleVal(outVals), nil
default:
if len(outVals) == 0 {
return cty.ListValEmpty(retType.ElementType()), nil
}
return cty.ListVal(outVals), nil
}
},
})
// SetProductFunc calculates the cartesian product of two or more sets or
// sequences. If the arguments are all lists then the result is a list of tuples,
// preserving the ordering of all of the input lists. Otherwise the result is a
// set of tuples.
var SetProductFunc = function.New(&function.Spec{
Params: []function.Parameter{},
VarParam: &function.Parameter{
Name: "sets",
Type: cty.DynamicPseudoType,
},
Type: func(args []cty.Value) (retType cty.Type, err error) {
if len(args) < 2 {
return cty.NilType, errors.New("at least two arguments are required")
}
listCount := 0
elemTys := make([]cty.Type, len(args))
for i, arg := range args {
aty := arg.Type()
switch {
case aty.IsSetType():
elemTys[i] = aty.ElementType()
case aty.IsListType():
elemTys[i] = aty.ElementType()
listCount++
case aty.IsTupleType():
// We can accept a tuple type only if there's some common type
// that all of its elements can be converted to.
allEtys := aty.TupleElementTypes()
if len(allEtys) == 0 {
elemTys[i] = cty.DynamicPseudoType
listCount++
break
}
ety, _ := convert.UnifyUnsafe(allEtys)
if ety == cty.NilType {
return cty.NilType, function.NewArgErrorf(i, "all elements must be of the same type")
}
elemTys[i] = ety
listCount++
default:
return cty.NilType, function.NewArgErrorf(i, "a set or a list is required")
}
}
if listCount == len(args) {
return cty.List(cty.Tuple(elemTys)), nil
}
return cty.Set(cty.Tuple(elemTys)), nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
ety := retType.ElementType()
total := 1
for _, arg := range args {
// Because of our type checking function, we are guaranteed that
// all of the arguments are known, non-null values of types that
// support LengthInt.
total *= arg.LengthInt()
}
if total == 0 {
// If any of the arguments was an empty collection then our result
// is also an empty collection, which we'll short-circuit here.
if retType.IsListType() {
return cty.ListValEmpty(ety), nil
}
return cty.SetValEmpty(ety), nil
}
subEtys := ety.TupleElementTypes()
product := make([][]cty.Value, total)
b := make([]cty.Value, total*len(args))
n := make([]int, len(args))
s := 0
argVals := make([][]cty.Value, len(args))
for i, arg := range args {
argVals[i] = arg.AsValueSlice()
}
for i := range product {
e := s + len(args)
pi := b[s:e]
product[i] = pi
s = e
for j, n := range n {
val := argVals[j][n]
ty := subEtys[j]
if !val.Type().Equals(ty) {
var err error
val, err = convert.Convert(val, ty)
if err != nil {
// Should never happen since we checked this in our
// type-checking function.
return cty.NilVal, fmt.Errorf("failed to convert argVals[%d][%d] to %s; this is a bug in Terraform", j, n, ty.FriendlyName())
}
}
pi[j] = val
}
for j := len(n) - 1; j >= 0; j-- {
n[j]++
if n[j] < len(argVals[j]) {
break
}
n[j] = 0
}
}
productVals := make([]cty.Value, total)
for i, vals := range product {
productVals[i] = cty.TupleVal(vals)
}
if retType.IsListType() {
return cty.ListVal(productVals), nil
}
return cty.SetVal(productVals), nil
},
})
// SliceFunc constructs a function that extracts some consecutive elements
// from within a list.
var SliceFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.DynamicPseudoType,
},
{
Name: "start_index",
Type: cty.Number,
},
{
Name: "end_index",
Type: cty.Number,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
arg := args[0]
argTy := arg.Type()
if argTy.IsSetType() {
return cty.NilType, function.NewArgErrorf(0, "cannot slice a set, because its elements do not have indices; use the tolist function to force conversion to list if the ordering of the result is not important")
}
if !argTy.IsListType() && !argTy.IsTupleType() {
return cty.NilType, function.NewArgErrorf(0, "must be a list or tuple value")
}
startIndex, endIndex, idxsKnown, err := sliceIndexes(args)
if err != nil {
return cty.NilType, err
}
if argTy.IsListType() {
return argTy, nil
}
if !idxsKnown {
// If we don't know our start/end indices then we can't predict
// the result type if we're planning to return a tuple.
return cty.DynamicPseudoType, nil
}
return cty.Tuple(argTy.TupleElementTypes()[startIndex:endIndex]), nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
inputList := args[0]
if retType == cty.DynamicPseudoType {
return cty.DynamicVal, nil
}
// we ignore idxsKnown return value here because the indices are always
// known here, or else the call would've short-circuited.
startIndex, endIndex, _, err := sliceIndexes(args)
if err != nil {
return cty.NilVal, err
}
if endIndex-startIndex == 0 {
if retType.IsTupleType() {
return cty.EmptyTupleVal, nil
}
return cty.ListValEmpty(retType.ElementType()), nil
}
outputList := inputList.AsValueSlice()[startIndex:endIndex]
if retType.IsTupleType() {
return cty.TupleVal(outputList), nil
}
return cty.ListVal(outputList), nil
},
})
func sliceIndexes(args []cty.Value) (int, int, bool, error) {
var startIndex, endIndex, length int
var startKnown, endKnown, lengthKnown bool
if args[0].Type().IsTupleType() || args[0].IsKnown() { // if it's a tuple then we always know the length by the type, but lists must be known
length = args[0].LengthInt()
lengthKnown = true
}
if args[1].IsKnown() {
if err := gocty.FromCtyValue(args[1], &startIndex); err != nil {
return 0, 0, false, function.NewArgErrorf(1, "invalid start index: %s", err)
}
if startIndex < 0 {
return 0, 0, false, function.NewArgErrorf(1, "start index must not be less than zero")
}
if lengthKnown && startIndex > length {
return 0, 0, false, function.NewArgErrorf(1, "start index must not be greater than the length of the list")
}
startKnown = true
}
if args[2].IsKnown() {
if err := gocty.FromCtyValue(args[2], &endIndex); err != nil {
return 0, 0, false, function.NewArgErrorf(2, "invalid end index: %s", err)
}
if endIndex < 0 {
return 0, 0, false, function.NewArgErrorf(2, "end index must not be less than zero")
}
if lengthKnown && endIndex > length {
return 0, 0, false, function.NewArgErrorf(2, "end index must not be greater than the length of the list")
}
endKnown = true
}
if startKnown && endKnown {
if startIndex > endIndex {
return 0, 0, false, function.NewArgErrorf(1, "start index must not be greater than end index")
}
}
return startIndex, endIndex, startKnown && endKnown, nil
}
// TransposeFunc contructs a function that takes a map of lists of strings and
// TransposeFunc constructs a function that takes a map of lists of strings and
// swaps the keys and values to produce a new map of lists of strings.
var TransposeFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "values",
Type: cty.Map(cty.List(cty.String)),
},
},
Type: function.StaticReturnType(cty.Map(cty.List(cty.String))),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
inputMap := args[0]
if !inputMap.IsWhollyKnown() {
return cty.UnknownVal(retType), nil
}
outputMap := make(map[string]cty.Value)
tmpMap := make(map[string][]string)
for it := inputMap.ElementIterator(); it.Next(); {
inKey, inVal := it.Element()
for iter := inVal.ElementIterator(); iter.Next(); {
_, val := iter.Element()
if !val.Type().Equals(cty.String) {
return cty.MapValEmpty(cty.List(cty.String)), errors.New("input must be a map of lists of strings")
}
outKey := val.AsString()
if _, ok := tmpMap[outKey]; !ok {
tmpMap[outKey] = make([]string, 0)
}
outVal := tmpMap[outKey]
outVal = append(outVal, inKey.AsString())
sort.Strings(outVal)
tmpMap[outKey] = outVal
}
}
for outKey, outVal := range tmpMap {
values := make([]cty.Value, 0)
for _, v := range outVal {
values = append(values, cty.StringVal(v))
}
outputMap[outKey] = cty.ListVal(values)
}
return cty.MapVal(outputMap), nil
},
})
// ValuesFunc constructs a function that returns a list of the map values,
// in the order of the sorted keys.
var ValuesFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "values",
Type: cty.DynamicPseudoType,
},
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
ty := args[0].Type()
if ty.IsMapType() {
return cty.List(ty.ElementType()), nil
} else if ty.IsObjectType() {
// The result is a tuple type with all of the same types as our
// object type's attributes, sorted in lexicographical order by the
// keys. (This matches the sort order guaranteed by ElementIterator
// on a cty object value.)
atys := ty.AttributeTypes()
if len(atys) == 0 {
return cty.EmptyTuple, nil
}
attrNames := make([]string, 0, len(atys))
for name := range atys {
attrNames = append(attrNames, name)
}
sort.Strings(attrNames)
tys := make([]cty.Type, len(attrNames))
for i, name := range attrNames {
tys[i] = atys[name]
}
return cty.Tuple(tys), nil
}
return cty.NilType, errors.New("values() requires a map as the first argument")
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
mapVar := args[0]
// We can just iterate the map/object value here because cty guarantees
// that these types always iterate in key lexicographical order.
var values []cty.Value
for it := mapVar.ElementIterator(); it.Next(); {
_, val := it.Element()
values = append(values, val)
}
if retType.IsTupleType() {
return cty.TupleVal(values), nil
}
if len(values) == 0 {
return cty.ListValEmpty(retType.ElementType()), nil
}
return cty.ListVal(values), nil
},
})
// ZipmapFunc constructs a function that constructs a map from a list of keys
// and a corresponding list of values.
var ZipmapFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "keys",
Type: cty.List(cty.String),
},
{
Name: "values",
Type: cty.DynamicPseudoType,
},
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
keys := args[0]
values := args[1]
valuesTy := values.Type()
switch {
case valuesTy.IsListType():
return cty.Map(values.Type().ElementType()), nil
case valuesTy.IsTupleType():
if !keys.IsWhollyKnown() {
// Since zipmap with a tuple produces an object, we need to know
// all of the key names before we can predict our result type.
return cty.DynamicPseudoType, nil
}
keysRaw := keys.AsValueSlice()
valueTypesRaw := valuesTy.TupleElementTypes()
if len(keysRaw) != len(valueTypesRaw) {
return cty.NilType, fmt.Errorf("number of keys (%d) does not match number of values (%d)", len(keysRaw), len(valueTypesRaw))
}
atys := make(map[string]cty.Type, len(valueTypesRaw))
for i, keyVal := range keysRaw {
if keyVal.IsNull() {
return cty.NilType, fmt.Errorf("keys list has null value at index %d", i)
}
key := keyVal.AsString()
atys[key] = valueTypesRaw[i]
}
return cty.Object(atys), nil
default:
return cty.NilType, errors.New("values argument must be a list or tuple value")
}
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
keys := args[0]
values := args[1]
if !keys.IsWhollyKnown() {
// Unknown map keys and object attributes are not supported, so
// our entire result must be unknown in this case.
return cty.UnknownVal(retType), nil
}
// both keys and values are guaranteed to be shallowly-known here,
// because our declared params above don't allow unknown or null values.
if keys.LengthInt() != values.LengthInt() {
return cty.NilVal, fmt.Errorf("number of keys (%d) does not match number of values (%d)", keys.LengthInt(), values.LengthInt())
}
output := make(map[string]cty.Value)
i := 0
for it := keys.ElementIterator(); it.Next(); {
_, v := it.Element()
val := values.Index(cty.NumberIntVal(int64(i)))
output[v.AsString()] = val
i++
}
switch {
case retType.IsMapType():
if len(output) == 0 {
return cty.MapValEmpty(retType.ElementType()), nil
}
return cty.MapVal(output), nil
case retType.IsObjectType():
return cty.ObjectVal(output), nil
default:
// Should never happen because the type-check function should've
// caught any other case.
return cty.NilVal, fmt.Errorf("internally selected incorrect result type %s (this is a bug)", retType.FriendlyName())
}
},
})
// helper function to add an element to a list, if it does not already exist
func appendIfMissing(slice []cty.Value, element cty.Value) ([]cty.Value, error) {
for _, ele := range slice {
eq, err := stdlib.Equal(ele, element)
if err != nil {
return slice, err
}
if eq.True() {
return slice, nil
}
}
return append(slice, element), nil
}
// Element returns a single element from a given list at the given index. If
// index is greater than the length of the list then it is wrapped modulo
// the list length.
func Element(list, index cty.Value) (cty.Value, error) {
return ElementFunc.Call([]cty.Value{list, index})
}
// Length returns the number of elements in the given collection or number of
// Unicode characters in the given string.
func Length(collection cty.Value) (cty.Value, error) {
return LengthFunc.Call([]cty.Value{collection})
}
// Coalesce takes any number of arguments and returns the first one that isn't empty.
func Coalesce(args ...cty.Value) (cty.Value, error) {
return CoalesceFunc.Call(args)
}
// CoalesceList takes any number of list arguments and returns the first one that isn't empty.
func CoalesceList(args ...cty.Value) (cty.Value, error) {
return CoalesceListFunc.Call(args)
}
// Compact takes a list of strings and returns a new list
// with any empty string elements removed.
func Compact(list cty.Value) (cty.Value, error) {
return CompactFunc.Call([]cty.Value{list})
}
// Contains determines whether a given list contains a given single value
// as one of its elements.
func Contains(list, value cty.Value) (cty.Value, error) {
return ContainsFunc.Call([]cty.Value{list, value})
}
// Index finds the element index for a given value in a list.
func Index(list, value cty.Value) (cty.Value, error) {
return IndexFunc.Call([]cty.Value{list, value})
}
// Distinct takes a list and returns a new list with any duplicate elements removed.
func Distinct(list cty.Value) (cty.Value, error) {
return DistinctFunc.Call([]cty.Value{list})
}
// Chunklist splits a single list into fixed-size chunks, returning a list of lists.
func Chunklist(list, size cty.Value) (cty.Value, error) {
return ChunklistFunc.Call([]cty.Value{list, size})
}
// Flatten takes a list and replaces any elements that are lists with a flattened
// sequence of the list contents.
func Flatten(list cty.Value) (cty.Value, error) {
return FlattenFunc.Call([]cty.Value{list})
}
// Keys takes a map and returns a sorted list of the map keys.
func Keys(inputMap cty.Value) (cty.Value, error) {
return KeysFunc.Call([]cty.Value{inputMap})
}
// List takes any number of list arguments and returns a list containing those
// values in the same order.
func List(args ...cty.Value) (cty.Value, error) {
return ListFunc.Call(args)
}
// Lookup performs a dynamic lookup into a map.
// There are two required arguments, map and key, plus an optional default,
// which is a value to return if no key is found in map.
func Lookup(args ...cty.Value) (cty.Value, error) {
return LookupFunc.Call(args)
}
// Map takes an even number of arguments and returns a map whose elements are constructed
// from consecutive pairs of arguments.
func Map(args ...cty.Value) (cty.Value, error) {
return MapFunc.Call(args)
}
// Matchkeys constructs a new list by taking a subset of elements from one list
// whose indexes match the corresponding indexes of values in another list.
func Matchkeys(values, keys, searchset cty.Value) (cty.Value, error) {
return MatchkeysFunc.Call([]cty.Value{values, keys, searchset})
}
// Merge takes an arbitrary number of maps and returns a single map that contains
// a merged set of elements from all of the maps.
//
// If more than one given map defines the same key then the one that is later in
// the argument sequence takes precedence.
func Merge(maps ...cty.Value) (cty.Value, error) {
return MergeFunc.Call(maps)
}
// Reverse takes a sequence and produces a new sequence of the same length
// with all of the same elements as the given sequence but in reverse order.
func Reverse(list cty.Value) (cty.Value, error) {
return ReverseFunc.Call([]cty.Value{list})
}
// SetProduct computes the cartesian product of sets or sequences.
func SetProduct(sets ...cty.Value) (cty.Value, error) {
return SetProductFunc.Call(sets)
}
// Slice extracts some consecutive elements from within a list.
func Slice(list, start, end cty.Value) (cty.Value, error) {
return SliceFunc.Call([]cty.Value{list, start, end})
}
// Transpose takes a map of lists of strings and swaps the keys and values to
// produce a new map of lists of strings.
func Transpose(values cty.Value) (cty.Value, error) {
return TransposeFunc.Call([]cty.Value{values})
}
// Values returns a list of the map values, in the order of the sorted keys.
// This function only works on flat maps.
func Values(values cty.Value) (cty.Value, error) {
return ValuesFunc.Call([]cty.Value{values})
}
// Zipmap constructs a map from a list of keys and a corresponding list of values.
func Zipmap(keys, values cty.Value) (cty.Value, error) {
return ZipmapFunc.Call([]cty.Value{keys, values})
}