internal/core/adt: remove unused code low-hanging fruit

Remove a field and type which are entirely unused,
and three functions which have not been used for a while either.

More unused code remains, particularly constants,
but these seem like the easiest ones to let go of.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: Ie0100b84ed43b014cd856d1bba97edb45cb7cc81
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1212275
Unity-Result: CUE porcuepine <[email protected]>
Reviewed-by: Marcel van Lohuizen <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>

Author: mvdan

Diff for: internal/core/adt/debug.go

@@ -158,8 +158,6 @@ type mermaidContext struct {
 
 	hasError bool
 
-	refRoot map[defID]*mermaidVertex
-
 	// roots maps a Vertex to the analysis data for that Vertex.
 	roots map[*Vertex]*mermaidVertex
 

Diff for: internal/core/adt/disjunct2.go

@@ -205,11 +205,6 @@ type disjunct struct {
 	mode      defaultMode
 }
 
-// TODO: remove this type.
-type disjunctHole struct {
-	holeID int
-}
-
 func (n *nodeContext) scheduleDisjunction(d envDisjunct) {
 	if len(n.disjunctions) == 0 {
 		// This processes all disjunctions in a single pass.

Diff for: internal/core/adt/states.go

@@ -339,20 +339,3 @@ func (n *nodeContext) scheduleTask(r *runner, env *Environment, x Node, ci Close
 	n.insertTask(t)
 	return t
 }
-
-// require ensures that a given condition is met for the given Vertex by
-// evaluating it. It yields execution back to the scheduler if it cannot
-// be completed at this point.
-func (c *OpContext) require(v *Vertex, needs condition) {
-	state := v.getState(c)
-	if state == nil {
-		return
-	}
-	state.process(needs, yield)
-}
-
-// scalarValue evaluates the given expression and either returns a
-// concrete value or schedules the task for later evaluation.
-func (ctx *OpContext) scalarValue(t *task, x Expr) Value {
-	return ctx.value(x, require(0, scalarKnown))
-}

Diff for: internal/core/adt/tasks.go

@@ -216,11 +216,6 @@ func processDisjunctions(c *OpContext, t *task, mode runMode) {
 	t.err = CombineErrors(nil, t.err, err)
 }
 
-func processFinalizeDisjunctions(c *OpContext, t *task, mode runMode) {
-	n := t.node
-	n.finalizeDisjunctions()
-}
-
 func processListLit(c *OpContext, t *task, mode runMode) {
 	n := t.node