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// 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 cue
import (
"cuelang.org/go/cue/ast"
"cuelang.org/go/cue/build"
"cuelang.org/go/cue/errors"
"cuelang.org/go/internal"
"cuelang.org/go/internal/core/adt"
"cuelang.org/go/internal/core/compile"
"cuelang.org/go/internal/core/convert"
"cuelang.org/go/internal/core/eval"
)
// An Instance defines a single configuration based on a collection of
// underlying CUE files.
type Instance struct {
*index
root *adt.Vertex
ImportPath string
Dir string
PkgName string
DisplayName string
Incomplete bool // true if Pkg and all its dependencies are free of errors
Err errors.Error // non-nil if the package had errors
inst *build.Instance
// complete bool // for cycle detection
}
func (x *index) addInst(p *Instance) *Instance {
if p.inst == nil {
p.inst = &build.Instance{
ImportPath: p.ImportPath,
PkgName: p.PkgName,
}
}
// fmt.Println(p.ImportPath, "XXX")
x.AddInst(p.ImportPath, p.root, p.inst)
x.loaded[p.inst] = p
p.index = x
return p
}
func (x *index) getImportFromBuild(p *build.Instance, v *adt.Vertex) *Instance {
inst := x.loaded[p]
if inst != nil {
return inst
}
inst = &Instance{
ImportPath: p.ImportPath,
Dir: p.Dir,
PkgName: p.PkgName,
DisplayName: p.ImportPath,
root: v,
inst: p,
index: x,
}
if p.Err != nil {
inst.setListOrError(p.Err)
}
x.loaded[p] = inst
return inst
}
func (x *index) getImportFromNode(v *adt.Vertex) *Instance {
p := x.GetInstanceFromNode(v)
if p == nil {
return nil
}
return x.getImportFromBuild(p, v)
}
func (x *index) getImportFromPath(id string) *Instance {
node, _ := x.LoadImport(id)
if node == nil {
return nil
}
b := x.GetInstanceFromNode(node)
inst := x.loaded[b]
if inst == nil {
inst = &Instance{
ImportPath: b.ImportPath,
PkgName: b.PkgName,
root: node,
inst: b,
index: x,
}
}
return inst
}
func init() {
internal.MakeInstance = func(value interface{}) interface{} {
v := value.(Value)
x := v.eval(v.ctx())
st, ok := x.(*adt.Vertex)
if !ok {
st = &adt.Vertex{}
st.AddConjunct(adt.MakeRootConjunct(nil, x))
}
return v.ctx().index.addInst(&Instance{
root: st,
})
}
}
// newInstance creates a new instance. Use Insert to populate the instance.
func newInstance(x *index, p *build.Instance, v *adt.Vertex) *Instance {
// TODO: associate root source with structLit.
inst := &Instance{
root: v,
inst: p,
}
if p != nil {
inst.ImportPath = p.ImportPath
inst.Dir = p.Dir
inst.PkgName = p.PkgName
inst.DisplayName = p.ImportPath
if p.Err != nil {
inst.setListOrError(p.Err)
}
}
x.AddInst(p.ImportPath, v, p)
x.loaded[p] = inst
inst.index = x
return inst
}
func (inst *Instance) setListOrError(err errors.Error) {
inst.Incomplete = true
inst.Err = errors.Append(inst.Err, err)
}
func (inst *Instance) setError(err errors.Error) {
inst.Incomplete = true
inst.Err = errors.Append(inst.Err, err)
}
func (inst *Instance) eval(ctx *context) adt.Value {
// TODO: remove manifest here?
v := ctx.manifest(inst.root)
return v
}
func init() {
internal.EvalExpr = func(value, expr interface{}) interface{} {
v := value.(Value)
e := expr.(ast.Expr)
ctx := v.idx.newContext()
return newValueRoot(ctx, evalExpr(ctx, v.vertex(ctx), e))
}
}
// pkgID reports a package path that can never resolve to a valid package.
func pkgID() string {
return "_"
}
// evalExpr evaluates expr within scope.
func evalExpr(ctx *context, scope *adt.Vertex, expr ast.Expr) adt.Value {
cfg := &compile.Config{
Scope: scope,
Imports: func(x *ast.Ident) (pkgPath string) {
if !isBuiltin(x.Name) {
return ""
}
return x.Name
},
}
c, err := compile.Expr(cfg, ctx.opCtx, pkgID(), expr)
if err != nil {
return &adt.Bottom{Err: err}
}
return adt.Resolve(ctx.opCtx, c)
// scope.Finalize(ctx.opCtx) // TODO: not appropriate here.
// switch s := scope.Value.(type) {
// case *bottom:
// return s
// case *adt.StructMarker:
// default:
// return ctx.mkErr(scope, "instance is not a struct, found %s", scope.Kind())
// }
// c := ctx.opCtx
// x, err := compile.Expr(&compile.Config{Scope: scope}, c.Runtime, expr)
// if err != nil {
// return c.NewErrf("could not evaluate %s: %v", c.Str(x), err)
// }
// env := &adt.Environment{Vertex: scope}
// switch v := x.(type) {
// case adt.Value:
// return v
// case adt.Resolver:
// r, err := c.Resolve(env, v)
// if err != nil {
// return err
// }
// return r
// case adt.Evaluator:
// e, _ := c.Evaluate(env, x)
// return e
// }
// return c.NewErrf("could not evaluate %s", c.Str(x))
}
// ID returns the package identifier that uniquely qualifies module and
// package name.
func (inst *Instance) ID() string {
if inst == nil || inst.inst == nil {
return ""
}
return inst.inst.ID()
}
// Doc returns the package comments for this instance.
func (inst *Instance) Doc() []*ast.CommentGroup {
var docs []*ast.CommentGroup
if inst.inst == nil {
return nil
}
for _, f := range inst.inst.Files {
if c := internal.FileComment(f); c != nil {
docs = append(docs, c)
}
}
return docs
}
// Value returns the root value of the configuration. If the configuration
// defines in emit value, it will be that value. Otherwise it will be all
// top-level values.
func (inst *Instance) Value() Value {
ctx := inst.newContext()
inst.root.Finalize(ctx.opCtx)
return newVertexRoot(ctx, inst.root)
}
// Eval evaluates an expression within an existing instance.
//
// Expressions may refer to builtin packages if they can be uniquely identified.
func (inst *Instance) Eval(expr ast.Expr) Value {
ctx := inst.newContext()
v := inst.root
v.Finalize(ctx.opCtx)
result := evalExpr(ctx, v, expr)
return newValueRoot(ctx, result)
}
// Merge unifies the given instances into a single one.
//
// Deprecated: do not use.
func Merge(inst ...*Instance) *Instance {
v := &adt.Vertex{}
i := inst[0]
ctx := i.index.newContext().opCtx
// TODO: interesting test: use actual unification and then on K8s corpus.
for _, i := range inst {
w := i.Value()
v.AddConjunct(adt.MakeRootConjunct(nil, w.v.ToDataAll()))
}
v.Finalize(ctx)
p := i.index.addInst(&Instance{
root: v,
// complete: true,
})
return p
}
// Build creates a new instance from the build instances, allowing unbound
// identifier to bind to the top-level field in inst. The top-level fields in
// inst take precedence over predeclared identifier and builtin functions.
func (inst *Instance) Build(p *build.Instance) *Instance {
p.Complete()
idx := inst.index
r := inst.index.Runtime
rErr := r.ResolveFiles(p)
cfg := &compile.Config{Scope: inst.root}
v, err := compile.Files(cfg, r, p.ID(), p.Files...)
v.AddConjunct(adt.MakeRootConjunct(nil, inst.root))
i := newInstance(idx, p, v)
if rErr != nil {
i.setListOrError(rErr)
}
if i.Err != nil {
i.setListOrError(i.Err)
}
if err != nil {
i.setListOrError(err)
}
// i.complete = true
return i
}
func (inst *Instance) value() Value {
return newVertexRoot(inst.newContext(), inst.root)
}
// Lookup reports the value at a path starting from the top level struct. The
// Exists method of the returned value will report false if the path did not
// exist. The Err method reports if any error occurred during evaluation. The
// empty path returns the top-level configuration struct. Use LookupDef for definitions or LookupField for
// any kind of field.
func (inst *Instance) Lookup(path ...string) Value {
return inst.value().Lookup(path...)
}
// LookupDef reports the definition with the given name within struct v. The
// Exists method of the returned value will report false if the definition did
// not exist. The Err method reports if any error occurred during evaluation.
func (inst *Instance) LookupDef(path string) Value {
return inst.value().LookupDef(path)
}
// LookupField reports a Field at a path starting from v, or an error if the
// path is not. The empty path returns v itself.
//
// It cannot look up hidden or unexported fields.
//
// Deprecated: this API does not work with new-style definitions. Use
// FieldByName defined on inst.Value().
func (inst *Instance) LookupField(path ...string) (f FieldInfo, err error) {
v := inst.value()
for _, k := range path {
s, err := v.Struct()
if err != nil {
return f, err
}
f, err = s.FieldByName(k, true)
if err != nil {
return f, err
}
if f.IsHidden {
return f, errNotFound
}
v = f.Value
}
return f, err
}
// Fill creates a new instance with the values of the old instance unified with
// the given value. It is not possible to update the emit value.
//
// Values may be any Go value that can be converted to CUE, an ast.Expr or
// a Value. In the latter case, it will panic if the Value is not from the same
// Runtime.
func (inst *Instance) Fill(x interface{}, path ...string) (*Instance, error) {
for i := len(path) - 1; i >= 0; i-- {
x = map[string]interface{}{path[i]: x}
}
a := make([]adt.Conjunct, len(inst.root.Conjuncts))
copy(a, inst.root.Conjuncts)
u := &adt.Vertex{Conjuncts: a}
if v, ok := x.(Value); ok {
if inst.index != v.idx {
panic("value of type Value is not created with same Runtime as Instance")
}
for _, c := range v.v.Conjuncts {
u.AddConjunct(c)
}
} else {
ctx := eval.NewContext(inst.index.Runtime, nil)
expr := convert.GoValueToExpr(ctx, true, x)
u.AddConjunct(adt.MakeRootConjunct(nil, expr))
u.Finalize(ctx)
}
inst = inst.index.addInst(&Instance{
root: u,
inst: nil,
// Omit ImportPath to indicate this is not an importable package.
Dir: inst.Dir,
PkgName: inst.PkgName,
Incomplete: inst.Incomplete,
// complete: true,
})
return inst, nil
}