internal/core: automated rename

This is to support the comprehension changes. As part of this
change, (partial) comprehensions can be the expression of a
Conjunct. This means that `Expr` must now return an `Elem`.

We will also need an `Expr` method that will return the comprehension
value when applicable. To avoid awkward naming, and to minimize diffs
and make changes clear, we do this rename in a separate CL.

Change-Id: I7cbbb81302519d8e4ba0727e7eb53d59be693f2f
Signed-off-by: Marcel van Lohuizen <mpvl@golang.org>
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/529512
Unity-Result: CUEcueckoo <cueckoo@cuelang.org>
Reviewed-by: Marcel van Lohuizen <mpvl@gmail.com>

Author: mpvl

cue/types.go

@@ -644,7 +644,7 @@ func Dereference(v Value) Value {
 	}
 
 	c := n.Conjuncts[0]
-	r, _ := c.Expr().(adt.Resolver)
+	r, _ := c.Elem().(adt.Resolver)
 	if r == nil {
 		return v
 	}
@@ -1072,7 +1072,7 @@ func (v hiddenValue) Split() []Value {
 	}
 	a := []Value{}
 	for _, x := range v.v.Conjuncts {
-		a = append(a, remakeValue(v, x.Env, x.Expr()))
+		a = append(a, remakeValue(v, x.Env, x.Elem()))
 	}
 	return a
 }
@@ -1932,7 +1932,7 @@ func (v Value) ReferencePath() (root Value, p Path) {
 	ctx := v.ctx()
 	c := v.v.Conjuncts[0]
 
-	x, path := reference(v.idx, ctx, c.Env, c.Expr())
+	x, path := reference(v.idx, ctx, c.Env, c.Elem())
 	if x == nil {
 		return Value{}, Path{}
 	}
@@ -2237,7 +2237,7 @@ func (v Value) Expr() (Op, []Value) {
 			// the default case, processed below.
 			c := v.v.Conjuncts[0]
 			env = c.Env
-			expr = c.Expr()
+			expr = c.Elem()
 			if w, ok := expr.(*adt.Vertex); ok {
 				return Value{v.idx, w, v.parent_}.Expr()
 			}

internal/core/adt/adt.go

@@ -33,7 +33,7 @@ func Resolve(ctx *OpContext, c Conjunct) *Vertex {
 
 	var v Value
 
-	expr := c.Expr()
+	expr := c.Elem()
 	switch x := expr.(type) {
 	case Value:
 		v = x
@@ -54,7 +54,7 @@ func Resolve(ctx *OpContext, c Conjunct) *Vertex {
 	default:
 		// Unknown type.
 		v = ctx.NewErrf(
-			"could not evaluate expression %s of type %T", c.Expr(), c)
+			"could not evaluate expression %s of type %T", c.Elem(), c)
 	}
 
 	return ToVertex(v)

internal/core/adt/closed_test.go

@@ -40,7 +40,7 @@ func TestClosedness(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		st := expr.Expr().(*adt.StructLit)
+		st := expr.Elem().(*adt.StructLit)
 		st.Init()
 
 		return &adt.StructInfo{

internal/core/adt/composite.go

@@ -810,7 +810,7 @@ func (c *Conjunct) Field() Node {
 	return c.x
 }
 
-func (c *Conjunct) Expr() Expr {
+func (c *Conjunct) Elem() Expr {
 	switch x := c.x.(type) {
 	case Expr:
 		return x

internal/core/adt/default.go

@@ -72,7 +72,7 @@ func (v *Vertex) Default() *Vertex {
 		if w.Conjuncts == nil {
 			for _, c := range v.Conjuncts {
 				// TODO: preserve field information.
-				expr, _ := stripNonDefaults(c.Expr())
+				expr, _ := stripNonDefaults(c.Elem())
 				w.Conjuncts = append(w.Conjuncts, MakeRootConjunct(c.Env, expr))
 			}
 		}

internal/core/adt/eval.go

@@ -1174,7 +1174,7 @@ func (n *nodeContext) addExprConjunct(v Conjunct) {
 	env := v.Env
 	id := v.CloseInfo
 
-	switch x := v.Expr().(type) {
+	switch x := v.Elem().(type) {
 	case *Vertex:
 		if x.IsData() {
 			n.addValueConjunct(env, x, id)
@@ -1240,7 +1240,7 @@ func (n *nodeContext) evalExpr(v Conjunct) {
 		}
 	}()
 
-	switch x := v.Expr().(type) {
+	switch x := v.Elem().(type) {
 	case Resolver:
 		arc, err := ctx.Resolve(v.Env, x)
 		if err != nil && !err.IsIncomplete() {
@@ -1252,12 +1252,12 @@ func (n *nodeContext) evalExpr(v Conjunct) {
 			break
 		}
 
-		n.addVertexConjuncts(v.Env, v.CloseInfo, v.Expr(), arc, false)
+		n.addVertexConjuncts(v.Env, v.CloseInfo, v.Elem(), arc, false)
 
 	case Evaluator:
 		// Interpolation, UnaryExpr, BinaryExpr, CallExpr
 		// Could be unify?
-		val := ctx.evaluateRec(v.Env, v.Expr(), Partial)
+		val := ctx.evaluateRec(v.Env, v.Elem(), Partial)
 		if b, ok := val.(*Bottom); ok && b.IsIncomplete() {
 			n.exprs = append(n.exprs, envExpr{v, b})
 			break
@@ -1473,7 +1473,7 @@ func updateCyclic(c Conjunct, cyclic bool, deref *Vertex, a []*Vertex) Conjunct
 	if deref != nil {
 		env.Cycles = append(env.Cycles, deref)
 	}
-	return MakeConjunct(env, c.Expr(), c.CloseInfo)
+	return MakeConjunct(env, c.Elem(), c.CloseInfo)
 }
 
 func (n *nodeContext) addValueConjunct(env *Environment, v Value, id CloseInfo) {

internal/core/adt/expr.go

@@ -1687,7 +1687,7 @@ func (x *IfClause) yield(ctx *OpContext, f YieldFunc) {
 
 // An LetClause represents a let clause in a comprehension.
 //
-//    for k, v in src {}
+//    let x = y
 //
 type LetClause struct {
 	Src   *ast.LetClause

internal/core/compile/compile_test.go

@@ -67,7 +67,7 @@ func TestCompile(t *testing.T) {
 				fmt.Fprintln(t)
 			}
 			fmt.Fprintln(t, "---", t.Rel(f.Filename))
-			debug.WriteNode(t, r, v.Conjuncts[i].Expr(), &debug.Config{
+			debug.WriteNode(t, r, v.Conjuncts[i].Elem(), &debug.Config{
 				Cwd: t.Dir,
 			})
 		}
@@ -102,5 +102,5 @@ func TestX(t *testing.T) {
 	if err != nil {
 		t.Error(errors.Details(err, nil))
 	}
-	t.Error(debug.NodeString(r, arc.Conjuncts[0].Expr(), nil))
+	t.Error(debug.NodeString(r, arc.Conjuncts[0].Elem(), nil))
 }

internal/core/convert/go.go

@@ -765,7 +765,7 @@ store:
 			ctx.AddBottom(b)
 			x = b
 		} else {
-			x = c.Expr()
+			x = c.Elem()
 		}
 		ctx.StoreType(t, e, x)
 		return e, x

internal/core/debug/compact.go

@@ -39,7 +39,7 @@ func (w *compactPrinter) node(n adt.Node) {
 				if i > 0 {
 					w.string(" & ")
 				}
-				w.node(c.Expr())
+				w.node(c.Elem())
 			}
 			return
 		}