format.go

@@ -303,8 +303,8 @@ func checkNoRepeatedArm(body string, names []string) error {
 
 // arm is one alternative of a {a|b} token or one operand, split into the head
 // `template.head` resolves and the tail of a dotted path into it. A non-empty tail
-// is what makes the arm a held draw: its head is drawn once per expansion (see
-// compileOps).
+// makes the arm a held draw: a reference path's for the render, any other for the
+// expansion.
 type arm struct {
 	spelling    string // as written, for messages
 	head        string
@@ -314,6 +314,10 @@ type arm struct {
 	path        string   // head and tail, the one path every way of writing this read shares
 }
 
+func (a arm) isRefPath() bool {
+	return isRef(a.head) && len(a.tail) > 0
+}
+
 // splitArm splits one name into head and tail. refs maps a reference to what
 // linkRefs resolved it to; before linking, a reference is whole.
 func splitArm(name string, refs map[string]refBinding) arm {
@@ -397,7 +401,7 @@ type firstReach struct {
 }
 
 func (c *formatOps) holdName(a arm, label string) {
-	if isRef(a.head) && len(a.tail) > 0 {
+	if a.isRefPath() {
 		return
 	}
 	if c.held == nil {

render.go

@@ -156,7 +156,7 @@ func expand(s *generatorState, t *template, sc renderScope) string {
 // read one row, either read twice gives one value, and a shown operand is the operand
 // computed. Every other name is drawn afresh, so {word} {word} still draws twice.
 func readField(s *generatorState, t *template, hold *drawMemo, sc renderScope, a arm) readValue {
-	if isRef(a.head) && len(a.tail) > 0 {
+	if a.isRefPath() {
 		return readReference(s, t, sc, a)
 	}
 	if sc.draws.trace != nil {

todo.md

@@ -56,9 +56,7 @@ This round, in order:
   which differs from the `pathCheck` type it wraps by word order alone: both architects
   placed them wrong.
 - Correct the claims readers followed wrong: `IsTemplate`'s doc says an argument holding
-  a bracket that is not valid JSON errors, where `misc.territory[SE]` is a path; `arm`'s
-  says a tail's head is drawn once per expansion, where a reference path is held per
-  render; the README says rows are indexed on the first draw, where `New` builds the key
+  a bracket that is not valid JSON errors, where `misc.territory[SE]` is a path; the README says rows are indexed on the first draw, where `New` builds the key
   map; and `loadDir`'s says it builds the tree deterministically, where it reports an
   unnamed rows file in map order.
 - Delete the comments the panel found restating their code or arranging the file: