| // Copyright 2018 The 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 yaml |
| |
| import ( |
| "bytes" |
| "io" |
| |
| "cuelang.org/go/cue" |
| "cuelang.org/go/cue/ast" |
| "cuelang.org/go/internal" |
| cueyaml "cuelang.org/go/internal/encoding/yaml" |
| "cuelang.org/go/internal/third_party/yaml" |
| ) |
| |
| // Marshal returns the YAML encoding of v. |
| func Marshal(v cue.Value) (string, error) { |
| if err := v.Validate(cue.Concrete(true)); err != nil { |
| if err := v.Validate(); err != nil { |
| return "", err |
| } |
| return "", internal.ErrIncomplete |
| } |
| n := v.Syntax(cue.Final(), cue.Concrete(true)) |
| b, err := cueyaml.Encode(n) |
| return string(b), err |
| } |
| |
| // MarshalStream returns the YAML encoding of v. |
| func MarshalStream(v cue.Value) (string, error) { |
| // TODO: return an io.Reader and allow asynchronous processing. |
| iter, err := v.List() |
| if err != nil { |
| return "", err |
| } |
| buf := &bytes.Buffer{} |
| for i := 0; iter.Next(); i++ { |
| if i > 0 { |
| buf.WriteString("---\n") |
| } |
| v := iter.Value() |
| if err := v.Validate(cue.Concrete(true)); err != nil { |
| if err := v.Validate(); err != nil { |
| return "", err |
| } |
| return "", internal.ErrIncomplete |
| } |
| n := v.Syntax(cue.Final(), cue.Concrete(true)) |
| b, err := cueyaml.Encode(n) |
| if err != nil { |
| return "", err |
| } |
| buf.Write(b) |
| } |
| return buf.String(), nil |
| } |
| |
| // Unmarshal parses the YAML to a CUE instance. |
| func Unmarshal(data []byte) (ast.Expr, error) { |
| return yaml.Unmarshal("", data) |
| } |
| |
| // Validate validates YAML and confirms it is an instance of the schema |
| // specified by v. If the YAML source is a stream, every object must match v. |
| func Validate(b []byte, v cue.Value) (bool, error) { |
| d, err := yaml.NewDecoder("yaml.Validate", b) |
| if err != nil { |
| return false, err |
| } |
| r := internal.GetRuntime(v).(*cue.Runtime) |
| for { |
| expr, err := d.Decode() |
| if err != nil { |
| if err == io.EOF { |
| return true, nil |
| } |
| return false, err |
| } |
| |
| inst, err := r.CompileExpr(expr) |
| if err != nil { |
| return false, err |
| } |
| |
| // TODO: consider using subsumption again here. |
| // Alternatives: |
| // - allow definition of non-concrete list, |
| // like list.Of(int), or []int. |
| // - Introduce ! in addition to ?, allowing: |
| // list!: [...] |
| // if err := v.Subsume(inst.Value(), cue.Final()); err != nil { |
| // return false, err |
| // } |
| x := v.Unify(inst.Value()) |
| if err := x.Err(); err != nil { |
| return false, err |
| } |
| if err := x.Validate(cue.Concrete(true)); err != nil { |
| return false, err |
| } |
| |
| } |
| } |
| |
| // ValidatePartial validates YAML and confirms it matches the constraints |
| // specified by v using unification. This means that b must be consistent with, |
| // but does not have to be an instance of v. If the YAML source is a stream, |
| // every object must match v. |
| func ValidatePartial(b []byte, v cue.Value) (bool, error) { |
| d, err := yaml.NewDecoder("yaml.ValidatePartial", b) |
| if err != nil { |
| return false, err |
| } |
| r := internal.GetRuntime(v).(*cue.Runtime) |
| for { |
| expr, err := d.Decode() |
| if err != nil { |
| if err == io.EOF { |
| return true, nil |
| } |
| return false, err |
| } |
| |
| inst, err := r.CompileExpr(expr) |
| if err != nil { |
| return false, err |
| } |
| |
| if x := v.Unify(inst.Value()); x.Err() != nil { |
| return false, x.Err() |
| } |
| } |
| } |