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fejkdata/doc.go
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// Package fejkdata generates fake data from recursive JSON templates.
//
// Data lives in JSON, not in Go. A generator starts from the shipped data set and
// layers any directories you add; folders and files become a dot-path namespace,
// then generate values by path:
//
// f, _ := fejkdata.New(fejkdata.WithSeed(42))
// f.Fake("sv_SE.address") // "Räfsalsvägen 43\n442 42 Kungälv"
// f.Fake("sv_SE.address.locality") // "Umeå": a second call draws afresh
//
// Several sources merge in order, the last winning a name clash, so custom data
// layers over the built-ins. The JSON template format is documented in the [README].
//
// [README]: https://github.com/larvit/fejkdata#readme
package fejkdata
// Vocabulary
//
// - draw — one item taken from a choice, or one row from a table: `drawItem`,
// `drawThroughChoices`, `renderEnv.drawRowOf`. Every {…} draws afresh, bar a read of a name.
// - expansion — one render of one format: `expand`.
// - render — one walk of the tree from an entry point, over one `frameStack`:
// `Generator.Fake`, `FakeRecord`, `Template.Fake` and `RecordTemplate.Fake`
// start one each, and `FakeStruct` one per record.
// - env — what a render reads names and rows through: `renderEnv`.
// - scope — where a name is bound: a category, or one repeat iteration: `nameScope`.
// - named pick — the draw a token such as {/person as p} binds to a name, drawn
// on its first read and kept while its scope renders: `nameBinding`,
// `namedPick`, `pickFrame`.
// - memo — what a named pick keeps its draws in, the variant drawn at each level
// and the value each path read: `drawMemo`.
// - level — a prefix of a read's path, from where it starts to its leaf; a choice and the
// variant drawn from it, or a table and its row, share one. `arm.levels` holds one pick
// key per level, and a step's `pathStep.at` indexes it.
// - pick key — the key a memo keeps a level's draw under, the level's path of segments:
// `pickKey`, `levelKeys`. A read through a name keys from the node its binding starts at,
// as ""; a fresh read keys from its head, and `pickKey.under` moves its keys under the
// key of the level it renders in.
// - addressed key — a pick key some read of a name lands on or passes, from the name's own
// level: `addressedKeys`. A fresh read rendering in a pick is kept in it only where its
// first level is addressed: `renderEnv.keeps`, `readUnder`.
// In data/geo/SE/address.json, {l.street.name} reads through {.locality as l} at the
// levels "", "street" and "street.name", the last its key, and {l.name} adds "name".
// Where {p} renders a category whose format reads {first}, and {p.first} sits beside
// it, that fresh read's key "first", under {p}'s "", is addressed: both read one draw.
// - pin — fixing which row of a table one path, or one named pick, uses:
// `pinSet`, `namedPick.pins`, `table.drawStep`.
// - 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
// links.
// - resolve — tying a reference or a name to what it names in the assembled tree:
// `resolveTemplates`, `resolveRefs`.
// - head — the string a read starts from: a field or a name as written, or a
// reference's category path with its sigil, /sv_SE.address: `arm.head`. The node it names is
// the read's start: `template.startOf`, `nameTarget.start`.
// - fence — a load-time check, run over each category, template or struct as it
// loads or compiles, so rendering a compiled tree cannot fail.