Create an anchor at the gap before the grapheme at index.

Anchors are stable positions that survive concurrent edits and merges: resolve one back to a current grapheme index with resolve_anchor. Before bias glues the anchor to the grapheme at index, so inserts at the gap push it right; After bias glues it to the grapheme at index - 1, so inserts at the gap land after it.

Examples

let doc = text.new(replica_id.new("A")) |> text.insert(0, "hello")
let cursor = text.anchor_at(doc, 5, sequence.After)
let doc = text.insert(doc, 0, "say ")
text.resolve_anchor(doc, cursor)  // -> 9

Decode an anchor from a JSON string produced by anchor_to_json.

Encode an anchor as a self-describing JSON value.

Insert a value at the end of the text. Appending is always valid, so no try_ variant exists.

Examples

text.new(replica_id.new("A"))
|> text.insert(0, "ab")
|> text.append("cd")
|> text.value()
// -> "abcd"

Append a value and return both the updated text and insertion delta.

Compact everything at or below a stability frontier.

Delegates to sequence.compact: stable tombstones are dropped, runs of stable graphemes are merged into compact blocks, and every dropped ID gets a forwarding entry so anchors and rebased operations still resolve. See lattice_sequence/sequence.compact for the stability contract.

Delete the value at the visible character index.

Panics with DeleteIndexOutOfBounds when index is outside [0, length). Use try_delete_with_delta to handle an untrusted index without crashing.

Delete the graphemes in [start, end).

Examples

text.new(replica_id.new("A"))
|> text.insert(0, "abcd")
|> text.delete_range(1, 3)
|> text.value()
// -> "ad"

Panics with RangeOutOfBounds when [start, end) is not a valid range in [0, length]. Use try_delete_range_with_delta to handle untrusted bounds without crashing.

Delete a grapheme range and return both the updated text and deletion delta.

Panics with RangeOutOfBounds when [start, end) is not a valid range in [0, length]. Use try_delete_range_with_delta to handle untrusted bounds without crashing.

Delete a value and return both the updated text and deletion delta.

Panics with DeleteIndexOutOfBounds when index is outside [0, length). Use try_delete_with_delta to handle an untrusted index without crashing.

Create an anchor at the end of the text. Always resolves to the current grapheme length, tracking growth.

Decode text from the canonical sequence JSON envelope.

The stability frontier this text was last compacted at.

Insert a value at the visible character index.

Panics with IndexOutOfBounds when index is outside [0, length]. Use try_insert_with_delta to handle an untrusted index without crashing.

Insert a value and return both the updated text and insertion delta.

Panics with IndexOutOfBounds when index is outside [0, length]. Use try_insert_with_delta to handle an untrusted index without crashing.

Count the visible graphemes in the text.

Examples

text.new(replica_id.new("A"))
|> text.insert(0, "a👍")
|> text.length()
// -> 2

Merge two text CRDT states.

Move the grapheme at from_index to to_index.

The to_index is interpreted after removing the grapheme from from_index.

Examples

text.new(replica_id.new("A"))
|> text.insert(0, "abc")
|> text.move(0, 2)
|> text.value()
// -> "bca"

Panics with a MoveError when either index is out of bounds. Use try_move_with_delta to handle untrusted indices without crashing.

Move a grapheme and return both the updated text and move delta.

Panics with a MoveError when either index is out of bounds. Use try_move_with_delta to handle untrusted indices without crashing.

Create an empty text CRDT for a replica.

Remove previously emitted forwarding entries from the text.

Forwardings are bounded by the host’s retention policy: keep the map returned by each compact round and expire old rounds by passing them here.

Replace the graphemes in [start, end) with a value.

Examples

text.new(replica_id.new("A"))
|> text.insert(0, "abcd")
|> text.replace_range(1, 3, "XY")
|> text.value()
// -> "aXYd"

Panics with RangeOutOfBounds when [start, end) is not a valid range in [0, length]. Use try_replace_range_with_delta to handle untrusted bounds without crashing.

Replace a grapheme range and return both the updated text and replacement delta.

Panics with RangeOutOfBounds when [start, end) is not a valid range in [0, length]. Use try_replace_range_with_delta to handle untrusted bounds without crashing.

Resolve an anchor to a current grapheme index in [0, length].

Anchors on deleted graphemes still resolve: they collapse to the gap where the grapheme used to be. Anchors follow moved graphemes. Panics with UnknownAnchorTarget when the target was never merged or was compacted away and its forwarding has expired — hosts holding anchors across compaction rounds should use try_resolve_anchor and treat failure as “re-anchor”.

Create an anchor at the start of the text. Always resolves to 0.

Return the graphemes in [start, end), clamping both indexes to the text bounds. An empty range (including start > end) yields "".

Examples

text.new(replica_id.new("A"))
|> text.insert(0, "abcd")
|> text.substring(1, 3)
// -> "bc"

Encode text using the canonical sequence JSON envelope.

Safely create an anchor at the gap before the grapheme at index.

Valid positions are 0 <= index <= length.

Safely delete a grapheme range and return both the updated text and deletion delta.

Safely delete a value and return both the updated text and deletion delta.

Safely insert a value and return both the updated text and insertion delta.

Safely move a grapheme and return both the updated text and move delta.

The to_index is interpreted after removing the grapheme from from_index.

Safely replace a grapheme range and return both the updated text and replacement delta.

Safely resolve an anchor to a current grapheme index in [0, length].

Anchors to compacted graphemes resolve through the forwarding map to the gap the grapheme left behind — semantically the same as tombstone collapse.

Returns Error(UnknownAnchorTarget) when the anchor references a grapheme this replica has never seen (created remotely and not yet merged), or one that was compacted away and whose forwarding entry has since been removed by the host’s retention policy. Either way the anchor is unusable and the holder should re-anchor.

Return the graphemes in [start, end), or an error when the range does not satisfy 0 <= start <= end <= length.

Examples

text.new(replica_id.new("A"))
|> text.insert(0, "abc")
|> text.try_substring(0, 4)
// -> Error(text.RangeOutOfBounds(start: 0, end: 4, length: 3))

Return the visible text as a single string.

Return the visible graphemes as a list.