internal/core/adt: more usage of Status

Getting the wrong status code can influence
evaluation negatively. This also is a step towards
hoisting the adt into a separate package.

Signed-off-by: Marcel van Lohuizen <[email protected]>
Change-Id: I2abe6e30cfebfdb00d791baec09c43d791754814
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1202262
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Matthew Sackman <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

internal/core/adt/composite.go

@@ -535,6 +535,11 @@ const (
 	finalized
 )
 
+// Status returns the status of the current node. When reading the status, one
+// should always use this method over directly reading status field.
+//
+// NOTE: this only matters for EvalV3 and beyonds, so a lot of the old code
+// might still access it directly.
 func (v *Vertex) Status() vertexStatus {
 	v = v.DerefValue()
 	return v.status
@@ -547,13 +552,13 @@ func (v *Vertex) ForceDone() {
 
 // IsUnprocessed reports whether v is unprocessed.
 func (v *Vertex) IsUnprocessed() bool {
-	return v.status == unprocessed
+	return v.Status() == unprocessed
 }
 
 func (v *Vertex) updateStatus(s vertexStatus) {
 	if !isCyclePlaceholder(v.BaseValue) {
 		if !v.IsErr() && v.state != nil {
-			Assertf(v.state.ctx, v.status <= s+1, "attempt to regress status from %d to %d", v.Status(), s)
+			Assertf(v.state.ctx, v.Status() <= s+1, "attempt to regress status from %d to %d", v.Status(), s)
 		}
 	}
 
@@ -677,8 +682,7 @@ func (v *Vertex) isFinal() bool {
 	// TODO(deref): the accounting of what is final should be recorded
 	// in the original node. Remove this dereference once the old
 	// evaluator has been removed.
-	v = v.DerefValue()
-	return v.status == finalized
+	return v.Status() == finalized
 }
 
 func (x *Vertex) IsConcrete() bool {

internal/core/adt/context.go

@@ -195,6 +195,7 @@ func New(v *Vertex, cfg *Config) *OpContext {
 	return ctx
 }
 
+// See also: unreachableForDev
 func (c *OpContext) isDevVersion() bool {
 	return c.Version == internal.DevVersion
 }
@@ -873,7 +874,7 @@ func (c *OpContext) unifyNode(v Expr, state combinedFlags) (result Value) {
 				n.process(arcTypeKnown, yield)
 			}
 		} else {
-			if v.isUndefined() || state.vertexStatus() > v.status {
+			if v.isUndefined() || state.vertexStatus() > v.Status() {
 				c.unify(v, state)
 			}
 		}

internal/core/adt/debug.go

@@ -404,7 +404,7 @@ func (m *mermaidContext) vertex(v *Vertex) *mermaidVertex {
 
 	var status string
 	switch {
-	case v.status == finalized:
+	case v.Status() == finalized:
 		status = "finalized"
 	case v.state == nil:
 		status = "ready"

internal/core/adt/eval.go

@@ -689,6 +689,8 @@ func (n *nodeContext) validateValue(state vertexStatus) {
 // incompleteErrors reports all errors from uncompleted conjuncts.
 // If final is true, errors are permanent and reported to parents.
 func (n *nodeContext) incompleteErrors(final bool) *Bottom {
+	unreachableForDev(n.ctx)
+
 	// collect incomplete errors.
 	var err *Bottom // n.incomplete
 	for _, d := range n.dynamicFields {
@@ -1474,7 +1476,7 @@ func (n *nodeContext) hasErr() bool {
 	if n.node.ChildErrors != nil {
 		return true
 	}
-	if n.node.status > evaluating && n.node.IsErr() {
+	if n.node.Status() > evaluating && n.node.IsErr() {
 		return true
 	}
 	return n.ctx.HasErr() || n.errs != nil

internal/core/adt/states.go

@@ -295,7 +295,7 @@ func (v *Vertex) allChildConjunctsKnown() bool {
 		return true
 	}
 
-	if v.status == finalized {
+	if v.Status() == finalized {
 		// This can happen, for instance, if this is called on a parent of a
 		// rooted node that is marked as a parent for a dynamic node.
 		// In practice this should be handled by the caller, but we add this