blob: 2dd37ca0fd41dccbe1afb92e4ed261d7577420ac [file] [log] [blame]
// Copyright 2019 CUE Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package struct defines utilities for struct types.
package structs
import (
"cuelang.org/go/cue"
"cuelang.org/go/cue/errors"
"cuelang.org/go/cue/token"
"cuelang.org/go/internal/core/adt"
)
// MinFields validates the minimum number of fields that are part of a struct.
// It can only be used as a validator, for instance `MinFields(3)`.
//
// Only fields that are part of the data model count. This excludes hidden
// fields, optional fields, and definitions.
func MinFields(object *cue.Struct, n int) *adt.Bottom {
iter := object.Fields(cue.Hidden(false), cue.Optional(false))
count := 0
for iter.Next() {
count++
}
if count < n {
return &adt.Bottom{
Code: adt.IncompleteError, // could still be resolved
Err: errors.Newf(token.NoPos, "len(fields) < MinFields(%[2]d) (%[1]d < %[2]d)", count, n),
}
}
return nil
}
// MaxFields validates the maximum number of fields that are part of a struct.
// It can only be used as a validator, for instance `MaxFields(3)`.
//
// Only fields that are part of the data model count. This excludes hidden
// fields, optional fields, and definitions.
func MaxFields(object *cue.Struct, n int) (bool, error) {
iter := object.Fields(cue.Hidden(false), cue.Optional(false))
count := 0
for iter.Next() {
count++
}
// permanent error is okay here.
return count <= n, nil
}