graph.go

@@ -61,7 +61,7 @@ func contained(n node) []namedNode {
 	case *template:
 		return namedNodes(n.fields)
 	case *table:
-		return append([]namedNode{{node: n.formatTemplate}}, namedNodes(n.fields)...)
+		return append([]namedNode{{node: n.formatTemplate}}, namedNodes(n.formatTemplate.fields)...)
 	case *tableColumn:
 		if len(n.t.cellTemplates) == 0 {
 			return nil

path.go

@@ -438,8 +438,8 @@ func (t *table) step(tail []string) (column node, child *table, err error) {
 	if len(tail) == 0 {
 		return nil, nil, nil
 	}
-	if i, ok := t.col[tail[0]]; ok {
+	if column, ok := t.formatTemplate.fields[tail[0]]; ok {
-		return t.fields[t.header[i]], nil, nil
+		return column, nil, nil
 	}
 	if child = t.descendant(tail[0]); child == nil {
 		return nil, nil, fmt.Errorf("no column or linked table %q in %s", tail[0], t.segment)

table.go

@@ -19,7 +19,6 @@ type table struct {
 	formatTemplate *template // fields are the column nodes
 	header         []string
 	col            map[string]int
-	fields         map[string]node // column nodes, the format's fields
 	rowNode        *tableRow
 	cells          []string // rows × columns, flat
 	cellTemplates  map[int]*template
@@ -157,7 +156,6 @@ func (t *table) parseRows(data string) error {
 	}
 	t.header = strings.Split(header, "\t")
 	t.col = make(map[string]int, len(t.header))
-	t.fields = make(map[string]node, len(t.header))
 	for i, name := range t.header {
 		if err := checkName(name); err != nil {
 			return fmt.Errorf("column %w", err)
@@ -166,7 +164,6 @@ func (t *table) parseRows(data string) error {
 			return fmt.Errorf("column %q is named twice", name)
 		}
 		t.col[name] = i
-		t.fields[name] = &tableColumn{t, i}
 	}
 	if header == data {
 		return fmt.Errorf("has no rows below its header; a table is at least two rows")
@@ -338,10 +335,14 @@ func (t *table) compileRowFormat(format string) error {
 			}
 		}
 	}
-	if err := checkTokens(toks, t.fields); err != nil {
+	fields := make(map[string]node, len(t.header))
+	for i, name := range t.header {
+		fields[name] = &tableColumn{t, i}
+	}
+	if err := checkTokens(toks, fields); err != nil {
 		return err
 	}
-	t.formatTemplate = &template{format: format, tokens: toks, fields: t.fields, repeat: 1, isRecord: true, site: tableSite{t, formatRow}}
+	t.formatTemplate = &template{format: format, tokens: toks, fields: fields, repeat: 1, isRecord: true, site: tableSite{t, formatRow}}
 	t.rowNode = &tableRow{t}
 	return nil
 }

todo.md

@@ -28,7 +28,6 @@ ranking `readSurvey.walk` hardest and all seven the unit they would least modify
 
 This round, in order:
 
-- Drop `table.fields` for `formatTemplate.fields`: one map held in two fields.
 - Rename `arm.key` to `head`, as `template.head` reads it, leaving `key` the table's key
   column; give `renderScope.row` a type that is not `tablePin`, since it pins nothing;
   and name `value.go` by the `valueProof` it holds.