From 822c8c0a5d6ae11acce872eb5058e9d71c885b53 Mon Sep 17 00:00:00 2001 From: Lilleman auf Larv Date: Wed, 7 Oct 2026 02:12:46 +0200 Subject: [PATCH] Name the path walks and steps by what each does: drawCallerPath, callerPathSteps, compiledPath, provePath, compileStep, childNamed, table.columnOrLinked, table.followStep and pathPos.fromRow --- arm.go | 2 +- doc.go | 2 +- docs/decisions.md | 10 ++++---- format.go | 2 +- path.go | 64 +++++++++++++++++++++++------------------------ path_test.go | 2 +- record.go | 2 +- reference.go | 2 +- render.go | 8 +++--- render_test.go | 4 +-- table.go | 32 ++++++++++++------------ todo.md | 10 ++++---- 12 files changed, 70 insertions(+), 70 deletions(-) diff --git a/arm.go b/arm.go index 6970178..70c9ff6 100644 --- a/arm.go +++ b/arm.go @@ -118,7 +118,7 @@ func (t *template) compileArm(name string, targets map[*nameBinding]nameTarget) } target := targets[b] full := append(target.tail[:len(target.tail):len(target.tail)], a.tail...) - if err := checkPathReaches(target.start, full, a.head); err != nil { + if err := provePath(target.start, full, a.head); err != nil { return a, err } w := compilePath(target.start, full) diff --git a/doc.go b/doc.go index da3ab66..abc03dc 100644 --- a/doc.go +++ b/doc.go @@ -44,7 +44,7 @@ package fejkdata // and {p.first} are read, the {first} that {p} renders has the key "first" under {p}'s // key "". {p.first} addresses "first", so both read one draw. // - pin — fixing which row of a table one path, or one named pick, uses: -// `pinSet`, `namedPick.pins`, `table.drawStep`. +// `pinSet`, `namedPick.pins`, `table.followStep`. // - link — a table's tie to its parent table, each row to its parent row: // `table.linkParent`. // - family — a table and every table reaching it through a chain of parent diff --git a/docs/decisions.md b/docs/decisions.md index 035f4ce..0e6eb29 100644 --- a/docs/decisions.md +++ b/docs/decisions.md @@ -798,12 +798,12 @@ the direct chain is the one a reader can predict from the tables' parents. 2026-09-30, larv-review on the comprehension round the maintainer approved on 2026-09-29; replaces "The path walks are separate loops". Goals 3 and 13: `drawSteps` draws every path from its steps, compiled when templates resolve, by -`pathCheck` or, for a caller's path, by `probePath` into a stack buffer. Both take each -step through `takeStep`, and differ only at a choice: the check walks every variant, the -probe the first. On 2026-09-29 one loop over all three walks, switching on a mode field, -leaked the check's leaves and errors with the draw's pins, arm and memo, since Go tracks a +`compiledPath` or, for a caller's path, by `callerPathSteps` into a stack buffer. Both take each +step through `compileStep`, and differ only at a choice: `compiledPath` walks every variant, +`callerPathSteps` the first. On 2026-09-29 one loop over all three walks, switching on a mode field, +leaked `compiledPath`'s leaves and errors with the draw's pins, arm and memo, since Go tracks a struct's fields as one, and a repeat of a reference path rose from 66 to 106 allocations. -`drawSteps` and `takeStep` take their state as parameters and a step holds no node, so no +`drawSteps` and `compileStep` take their state as parameters and a step holds no node, so no benchmark gained an allocation. Valid while Go's escape analysis tracks a struct's fields as one. diff --git a/format.go b/format.go index f311791..07e4511 100644 --- a/format.go +++ b/format.go @@ -158,7 +158,7 @@ func checkArm(name string, fields map[string]node, wholeToken bool) (missing boo } return true, fmt.Errorf("no field %q", a.head) } - if err := checkPathReaches(field, a.tail, a.head); err != nil { + if err := provePath(field, a.tail, a.head); err != nil { return false, fmt.Errorf("field %q: %w", a.head, err) } return false, nil diff --git a/path.go b/path.go index 7ec20d7..46c46a3 100644 --- a/path.go +++ b/path.go @@ -9,8 +9,8 @@ import ( "github.com/larvit/fejkdata/internal/invariant" ) -// stepInto is what seg names under n: a folder's entry or a template's field. -func stepInto(n node, seg string) (node, error) { +// childNamed is what seg names under n: a folder's entry or a template's field. +func childNamed(n node, seg string) (node, error) { switch { case grammar.IsSelector(seg): return nil, fmt.Errorf("%s is not a table, so it has no row to select", grammar.SelectorOf(seg)) @@ -37,7 +37,7 @@ func stepInto(n node, seg string) (node, error) { return nil, fmt.Errorf("no field %q: %q is a column, and a cell holds no fields", seg, n.name()) case *nullItem: default: - panic(invariant.Broken("stepInto has no case for node %T", n)) + panic(invariant.Broken("childNamed has no case for node %T", n)) } return nil, fmt.Errorf("no field %q", seg) } @@ -65,11 +65,11 @@ const ( stepParent // up to the table's parent, at the row its own row links to ) -// pathCheck proves a path reaches a node whichever way the draws go: every variant of a +// compiledPath is a path proved to reach a node whichever way the draws go: every variant of a // choice carries the rest of it, and is walked, a selector names a row inside the -// rows selected before it, and no level read carries a repeat. It compiles the steps +// rows selected before it, and no level read carries a repeat. It holds the steps // a draw takes, and every leaf the path may render; level names the head in its errors. -type pathCheck struct { +type compiledPath struct { pins pinSet level string tail []string @@ -77,18 +77,18 @@ type pathCheck struct { leaves []node } -func (w *pathCheck) run(n node) (node, error) { +func (w *compiledPath) run(n node) (node, error) { return w.walk(n, w.tail) } -func (w *pathCheck) walk(n node, tail []string) (node, error) { +func (w *compiledPath) walk(n node, tail []string) (node, error) { at := pathPos{n: n, tail: tail} for at.more() { if c, ok := at.n.(*choice); ok { return w.walkEvery(c, at.tail) } var err error - if w.steps, err = takeStep(&at, w.tail, w.level, w.steps, &w.pins); err != nil { + if w.steps, err = compileStep(&at, w.tail, w.level, w.steps, &w.pins); err != nil { return nil, err } } @@ -100,35 +100,35 @@ func repeatLevelError(level string) error { return fmt.Errorf("the level %q carries a repeat, so a path cannot read one draw of it; read %q whole", level, level) } -// pathPos is where a walk stands: the node reached, the tail left to walk from it, and route's -// descended flag for it. +// pathPos is where a walk stands: the node reached, the tail left to walk from it, and fromRow, +// whether the walk entered n, a table, from a row of a table linked to it. type pathPos struct { - n node - tail []string - descended bool + n node + tail []string + fromRow bool } -func (p pathPos) more() bool { return len(p.tail) > 0 || p.descended } +func (p pathPos) more() bool { return len(p.tail) > 0 || p.fromRow } -// takeStep takes the first step of at.tail from at.n, which must not be a choice, moves at past +// compileStep takes the first step of at.tail from at.n, which must not be a choice, moves at past // it, and appends the step to steps: a field, or the route through a table. whole is the full // path; level is the prefix an error puts before it. -func takeStep(at *pathPos, whole []string, level string, steps []pathStep, pins *pinSet) ([]pathStep, error) { +func compileStep(at *pathPos, whole []string, level string, steps []pathStep, pins *pinSet) ([]pathStep, error) { i := len(whole) - len(at.tail) switch x := at.n.(type) { case *table: - r, err := x.route(at.tail, at.descended) + r, err := x.route(at.tail, at.fromRow) if err != nil { return steps, err } - *at = pathPos{n: r.next, tail: r.rest, descended: r.descends} + *at = pathPos{n: r.next, tail: r.rest, fromRow: r.nextLinked} return routeSteps(steps, pins, x, r, i) case *template: if x.repeat > 1 && !grammar.IsSelector(at.tail[0]) { return steps, repeatLevelError(join(level, strings.Join(whole[:i], "."))) } } - next, err := stepInto(at.n, at.tail[0]) + next, err := childNamed(at.n, at.tail[0]) if err != nil { return steps, err } @@ -139,7 +139,7 @@ func takeStep(at *pathPos, whole []string, level string, steps []pathStep, pins // walkEvery walks every variant and keeps the first one's steps: every variant carries // the rest of the path, so each compiles to the same steps past the choice. -func (w *pathCheck) walkEvery(c *choice, tail []string) (node, error) { +func (w *compiledPath) walkEvery(c *choice, tail []string) (node, error) { if err := carriedByAll(c, tail); err != nil { return nil, err } @@ -159,10 +159,10 @@ func (w *pathCheck) walkEvery(c *choice, tail []string) (node, error) { return last, nil } -// probePath proves a path reaches a node without drawing, appending to steps the steps a -// draw takes. Where pathCheck walks every variant of a choice, it walks the first, +// callerPathSteps proves a path reaches a node without drawing, appending to steps the steps a +// draw takes. Where compiledPath walks every variant of a choice, it walks the first, // which carriedByAll lets stand for all. -func probePath(n node, tail []string, steps []pathStep) ([]pathStep, error) { +func callerPathSteps(n node, tail []string, steps []pathStep) ([]pathStep, error) { var pins pinSet for at := (pathPos{n: n, tail: tail}); at.more(); { if c, ok := at.n.(*choice); ok { @@ -173,7 +173,7 @@ func probePath(n node, tail []string, steps []pathStep) ([]pathStep, error) { continue } var err error - if steps, err = takeStep(&at, tail, "", steps, &pins); err != nil { + if steps, err = compileStep(&at, tail, "", steps, &pins); err != nil { return nil, err } } @@ -195,7 +195,7 @@ func drawSteps(s *drawstate.State, n node, steps []pathStep, pins *pinSet, memo } if st.kind == stepField { var err error - if n, err = stepInto(n, st.name); err != nil { + if n, err = childNamed(n, st.name); err != nil { panic(invariant.Broken("step %d: %v; a path's steps should have been compiled from the node they are drawn from", st.at, err)) } continue @@ -210,7 +210,7 @@ func drawSteps(s *drawstate.State, n node, steps []pathStep, pins *pinSet, memo case st.kind == stepChild && climbed != nil: pins, climbed = memo.stepDownPins(pins, climbed, levels, st.at), nil } - n = t.drawStep(s, st, pins) + n = t.followStep(s, st, pins) } return n, pins } @@ -241,14 +241,14 @@ func unreachableInChoice(c *choice, want string) error { return fmt.Errorf("not every variant of this %d-way choice carries %q; all carry %v", len(c.items), want, offered) } -func checkPathReaches(n node, tail []string, level string) error { - _, err := (&pathCheck{level: level, tail: tail}).run(n) +func provePath(n node, tail []string, level string) error { + _, err := (&compiledPath{level: level, tail: tail}).run(n) return err } -// compilePath compiles a path checkPathReaches proved. -func compilePath(n node, tail []string) pathCheck { - w := pathCheck{tail: tail} +// compilePath compiles a path provePath proved. +func compilePath(n node, tail []string) compiledPath { + w := compiledPath{tail: tail} if _, err := w.run(n); err != nil { panic(invariant.Broken("%s: %v; the path should have been proved before it was compiled", grammar.JoinSegments(tail), err)) } diff --git a/path_test.go b/path_test.go index dc43fab..5622dad 100644 --- a/path_test.go +++ b/path_test.go @@ -12,7 +12,7 @@ func TestPathCheckStopsAtAMissingSegment(t *testing.T) { if leaves := compilePath(n, []string{"a", "b"}).leaves; len(leaves) != 1 { t.Fatalf("compilePath(a.b).leaves = %v, want the one leaf", leaves) } - w := &pathCheck{tail: []string{"a", "nope", "deeper"}} + w := &compiledPath{tail: []string{"a", "nope", "deeper"}} _, err := w.run(n) if err == nil || !strings.Contains(err.Error(), `no field "nope"`) { t.Errorf("walk(a.nope.deeper) = %v, want the missing segment named", err) diff --git a/record.go b/record.go index 46b1935..5623b50 100644 --- a/record.go +++ b/record.go @@ -157,7 +157,7 @@ func (f *Generator) FakeRecord(path string) (*Record, error) { // tableRecord walks a path's tail from a table to the table whose row is the record, and that // row, selected or drawn. func tableRecord(s *drawstate.State, t *table, tail []string) (node, renderedRow, error) { - n, pins, err := descend(s, t, tail) + n, pins, err := drawCallerPath(s, t, tail) if err != nil { return nil, renderedRow{}, err } diff --git a/reference.go b/reference.go index 0943897..22fa76f 100644 --- a/reference.go +++ b/reference.go @@ -60,7 +60,7 @@ func (t *template) resolveRefs(folder []string, label, category string, root map if category != "" && head == "/"+category { return refs, fmt.Errorf("%s: reference {%s}: names the category it sits in; read a sibling field as a path, or move the shared value into its own category and reference that", label, name) } - if err := checkPathReaches(target, tail, head); err != nil { + if err := provePath(target, tail, head); err != nil { return refs, fmt.Errorf("%s: reference {%s}: %w", label, name, err) } refs.categories[head] = target diff --git a/render.go b/render.go index 1cccd5b..077224d 100644 --- a/render.go +++ b/render.go @@ -21,7 +21,7 @@ func (f *Generator) Fake(path string) (string, error) { return "", fmt.Errorf("fejkdata: %w", err) } f.loadShippedAt(segments) - n, pins, err := descend(f.drawState, &f.root, segments) + n, pins, err := drawCallerPath(f.drawState, &f.root, segments) if err != nil { return "", fmt.Errorf("fejkdata: %s: %w", path, err) } @@ -33,11 +33,11 @@ func (f *Generator) Fake(path string) (string, error) { return render(f.drawState, n, env), nil } -// descend walks a caller's path to the node it names, returning the rows its leaf renders in. -func descend(s *drawstate.State, root node, segments []string) (node, pinSet, error) { +// drawCallerPath walks a caller's path to the node it names, returning the rows its leaf renders in. +func drawCallerPath(s *drawstate.State, root node, segments []string) (node, pinSet, error) { // docs/decisions.md#a-path-is-walked-once-without-drawing-before-it-is-walked-for-real var buf [16]pathStep - steps, err := probePath(root, segments, buf[:0]) + steps, err := callerPathSteps(root, segments, buf[:0]) if err != nil { return nil, pinSet{}, err } diff --git a/render_test.go b/render_test.go index 1f4844d..32051d5 100644 --- a/render_test.go +++ b/render_test.go @@ -67,7 +67,7 @@ var nodeSwitchSkips = map[string][]string{ "columnItems": {"folder", "table", "tableRow"}, "prove": {"folder"}, "render": {"folder"}, - "stepInto": {"choice", "table", "tableRow"}, + "childNamed": {"choice", "table", "tableRow"}, } func TestNodeSwitchesHandleEveryKind(t *testing.T) { @@ -116,7 +116,7 @@ func TestNodeSwitchesHandleEveryKind(t *testing.T) { render(engine(1).drawState, n, renderEnv{frames: &frames, row: renderedRow{tbl, 0}}) }, "renderEdges": func(n node) { renderEdges(n) }, - "stepInto": func(n node) { _, _ = stepInto(n, "x") }, + "childNamed": func(n node) { _, _ = childNamed(n, "x") }, } { mustPanic(t, name+" on an unhandled node", func() { call(&unhandledNode{}) }) for _, kind := range kinds { diff --git a/table.go b/table.go index 0012740..7459202 100644 --- a/table.go +++ b/table.go @@ -237,19 +237,19 @@ func (t *table) linkParent(siblings map[string]node) error { // tableRoute is how a path passes one table: the row it reads, by selector or // drawn, what it goes on into, and whether that is a linked table. type tableRoute struct { - sel string - draw bool - next node - rest []string - descends bool - up bool + sel string + draw bool + next node + rest []string + nextLinked bool + up bool } -// route is how tail passes t. descended means the previous route stepped into t +// route is how tail passes t. fromRow means the previous route stepped into t // from a row of an ancestor table, so t reads a row even where tail is empty; a // table reached otherwise, with no selector and an empty tail, is left to a render's // own draw. -func (t *table) route(tail []string, descended bool) (tableRoute, error) { +func (t *table) route(tail []string, fromRow bool) (tableRoute, error) { sel, tail, err := t.selector(tail) if err != nil { return tableRoute{}, err @@ -258,14 +258,14 @@ func (t *table) route(tail []string, descended bool) (tableRoute, error) { if err := t.rows.ProveStepUp(tail[1:]); err != nil { return tableRoute{}, err } - return tableRoute{sel: sel, draw: sel == "", next: t.rows.Parent().Owner(), rest: tail[2:], descends: true, up: true}, nil + return tableRoute{sel: sel, draw: sel == "", next: t.rows.Parent().Owner(), rest: tail[2:], nextLinked: true, up: true}, nil } - column, child, err := t.step(tail) + column, child, err := t.columnOrLinked(tail) if err != nil { return tableRoute{}, err } selected := sel != "" - readsRow := selected || descended || len(tail) > 0 + readsRow := selected || fromRow || len(tail) > 0 // A selector further down pins this table by ancestry; drawing first could draw a row the // selector is not inside. pinnedBelow := grammar.HasSelector(tail) @@ -276,7 +276,7 @@ func (t *table) route(tail []string, descended bool) (tableRoute, error) { case len(tail) == 0: r.next = t.rowNode case child != nil: - r.next, r.rest, r.descends = child, tail[1:], true + r.next, r.rest, r.nextLinked = child, tail[1:], true default: r.next, r.rest = column, tail[1:] } @@ -315,7 +315,7 @@ func routeSteps(steps []pathStep, pins *pinSet, t *table, r tableRoute, at int) return steps, nil } -func (t *table) drawStep(s *drawstate.State, st pathStep, pins *pinSet) node { +func (t *table) followStep(s *drawstate.State, st pathStep, pins *pinSet) node { switch st.kind { case stepSelect: if err := pins.PinRow(t.rows, st.row); err != nil { @@ -334,7 +334,7 @@ func (t *table) drawStep(s *drawstate.State, st pathStep, pins *pinSet) node { case stepParent: return t.rows.Parent().Owner() } - panic(invariant.Broken("drawStep has no case for step kind %d", st.kind)) + panic(invariant.Broken("followStep has no case for step kind %d", st.kind)) } func (t *table) selector(tail []string) (sel string, rest []string, err error) { @@ -348,8 +348,8 @@ func (t *table) selector(tail []string) (sel string, rest []string, err error) { return sel, rest, nil } -// step is what a tail's first segment names in t: a column, or a table linked to it. -func (t *table) step(tail []string) (column node, child *table, err error) { +// columnOrLinked is what a tail's first segment names in t: a column, or a table linked to it. +func (t *table) columnOrLinked(tail []string) (column node, child *table, err error) { if len(tail) == 0 { return nil, nil, nil } diff --git a/todo.md b/todo.md index e148fdf..396fd15 100644 --- a/todo.md +++ b/todo.md @@ -82,7 +82,7 @@ | 110 | 0.1.0 | | **Refuse an empty segment in a path `Fake`, `FakeRecord` and the CLI take, as a reference does: `sv_SE.person.` reports `path has an empty segment`.** | 1 | 1 | 3 | 6 | 6 | 13.8 | | 79 | 0.1.0 | decision | **Beside a `--data-path`, load in `New` the user's categories, the shipped ones they override or read, and the shipped ones whose reads reach an overridden one; load the rest on first reach.** | 6 | 6 | 7 | 8 | 13 | 12.9 | | 131 | 0.1.0 | | **Move `frameStack` into `env.go`, beside the methods that push and search it, and move `nameTargets`, `addressedKeys` and `nameUses` from `resolve.go` into `name.go`.** | 1 | 3 | 1 | 7 | 3.2, 3.1 | 12.8 | -| 132 | 0.1.0 | | **Name the path walks and steps by what each does, so `descend`, `probePath`, `pathCheck`, `checkPathReaches`, `compilePath`, `takeStep`, `stepInto` and `table.step` can be told apart by name, `table.drawStep` stops sitting one letter from `drawSteps`, and `pathPos.descended` says what it holds.** | 2 | 3 | 1 | 7 | 3.3 | 11.8 | +| 132 | 0.1.0 | | **Name the path walks and steps by what each does, so `descend`, `probePath`, `pathCheck`, `checkPathReaches`, `compilePath`, `takeStep`, `childNamed` and `table.step` can be told apart by name, `table.drawStep` stops sitting one letter from `drawSteps`, and `pathPos.descended` says what it holds.** | 2 | 3 | 1 | 7 | 3.3 | 11.8 | | 134 | 0.1.0 | | **Hold `nameBinding`'s target in a named field, so `b.target.tail` shows that `resolveTemplates` fills it.** | 1 | 2 | 1 | 6 | 3.3, 3.2 | 11.3 | | 136 | 0.1.0 | | **Rename `grammar.NameRead` and `grammar.CheckName` for what they read and check, so a name in the engine is only a bound name.** | 1 | 2 | 1 | 6 | 3.3 | 11.3 | | 135 | 0.1.0 | | **Choose `disagreement`'s message from one table over the two items' kinds.** | 2 | 2 | 1 | 6 | 3.2 | 10.3 | @@ -120,7 +120,7 @@ | 108 | 0.2.0 | defect | **Name item 26 in the decision "No builtin reads the clock, so a date is bounded by days, never by an age", as the item that ends its conflict with goal 4.** | 1 | 1 | 1 | 4 | 3.4 | 8.0 | | 14 | 0.3.0 | | **Spell `misc.creditcard`'s digit runs `{digits(n)}`.** | 2 | 2 | 4 | 6 | 5.7 | 15.1 | | 38 | 0.3.0 | defect | **Compare `calcParser.binary`'s operator as a rune.** | 1 | 1 | 3 | 6 | 6 | 13.8 | -| 45 | 0.3.0 | | **Name the node a selector follows in `stepInto`'s refusal.** | 1 | 1 | 3 | 6 | 6 | 13.8 | +| 45 | 0.3.0 | | **Name the node a selector follows in `childNamed`'s refusal.** | 1 | 1 | 3 | 6 | 6 | 13.8 | | 49 | 0.3.0 | | **Report a CRLF rows file holding only its header as having no rows.** | 1 | 1 | 3 | 6 | 6 | 13.8 | | 13 | 0.3.0 | defect | **Place xlsx cells by their `r` reference in `data-import/xlsx.py`.** | 2 | 2 | 3 | 6 | 4 | 13.7 | | 39 | 0.3.0 | | **Stop the `columnKinds` suggestion naming a field's own kind or a narrower one.** | 1 | 2 | 3 | 6 | 6 | 13.5 | @@ -299,9 +299,9 @@ The decision "With only the shipped set, a category loads on the first call reac Both inherited architects, in the panel and in the scoring run, ranked one change first: gather the runtime that keeps a name's pick in one file. `frameStack` sits in `pick.go` while `env.go` pushes and searches it, and the name steps of `resolveTemplates` sit apart from `name.go`. Revise the README's Layout block with it. -### 132. Name the path walks and steps by what each does, so `descend`, `probePath`, `pathCheck`, `checkPathReaches`, `compilePath`, `takeStep`, `stepInto` and `table.step` can be told apart by name, `table.drawStep` stops sitting one letter from `drawSteps`, and `pathPos.descended` says what it holds. +### 132. Name the path walks and steps by what each does, so `descend`, `probePath`, `pathCheck`, `checkPathReaches`, `compilePath`, `takeStep`, `childNamed` and `table.step` can be told apart by name, `table.drawStep` stops sitting one letter from `drawSteps`, and `pathPos.descended` says what it holds. -Six of the nine seats of the 2026-10-07 panel named these names: five entry points walk a path, `descend`, `probePath`, `pathCheck`, `checkPathReaches` and `compilePath`, and five units with near names step through one, `takeStep`, `stepInto`, `table.step`, `table.drawStep` and `drawSteps`; and `pathPos.descended`'s doc, "route's descended flag for it", defines it by its reader. +Six of the nine seats of the 2026-10-07 panel named these names: five entry points walk a path, `descend`, `probePath`, `pathCheck`, `checkPathReaches` and `compilePath`, and five units with near names step through one, `takeStep`, `childNamed`, `table.step`, `table.drawStep` and `drawSteps`; and `pathPos.descended`'s doc, "route's descended flag for it", defines it by its reader. ### 134. Hold `nameBinding`'s target in a named field, so `b.target.tail` shows that `resolveTemplates` fills it. @@ -446,7 +446,7 @@ A `"repeat": 14` over `{digits(1)}` draws every 14-digit run with the odds `{dig `byte(p.rs[p.pos])` reads U+012B `ī` as `+`, so `{calc(a ī b)}` compiles as `a + b`. -### 45. Name the node a selector follows in `stepInto`'s refusal. +### 45. Name the node a selector follows in `childNamed`'s refusal. `sv_SE.person[1].first` answers `1 is not a table`.