A piece table data structure implemented using red-black tree.
In computing, a piece table is a data structure typically used to represent a text document while it is edited in a text editor. Initially a reference (or 'span') to the whole of the original file is created, which represents the as yet unchanged file. Subsequent inserts and deletes replace a span by combinations of one, two, or three references to sections of either the original document or to a buffer holding inserted text.
— Crowley, Charles (10 June 1998). "Data Structures for Text Sequences - 6.4 The piece table method"
deno add jsr:@eu-ge-ne/slice-tree# pnpm
pnpm i jsr:@eu-ge-ne/slice-tree
# yarn
yarn add jsr:@eu-ge-ne/slice-tree
# npm
npx jsr add @eu-ge-ne/slice-treebunx jsr add @eu-ge-ne/slice-treeimport { assertEquals } from "jsr:@std/assert";
import { SliceTree } from "jsr:@eu-ge-ne/slice-tree";
const text = new SliceTree();
assertEquals(text.count, 0);
assertEquals(text.line_count, 0);
assertEquals(text.read(0).toArray().join(""), "");
assertEquals(text.line(0).toArray().join(""), "");
text.write(0, "Lorem");
assertEquals(text.count, 5);
assertEquals(text.line_count, 1);
assertEquals(text.read(0).toArray().join(""), "Lorem");
assertEquals(text.line(0).toArray().join(""), "Lorem");
text.write(5, "ipsum");
assertEquals(text.count, 10);
assertEquals(text.line_count, 1);
assertEquals(text.read(0).toArray().join(""), "Loremipsum");
assertEquals(text.line(0).toArray().join(""), "Loremipsum");
text.write(5, "\n");
text.write(11, "\n");
assertEquals(text.count, 12);
assertEquals(text.line_count, 3);
assertEquals(text.read(0).toArray().join(""), "Lorem\nipsum\n");
assertEquals(text.line(0).toArray().join(""), "Lorem\n");
assertEquals(text.line(1).toArray().join(""), "ipsum\n");
assertEquals(text.line(2).toArray().join(""), "");
text.erase(0, 6);
text.erase(5, 1);
assertEquals(text.count, 5);
assertEquals(text.line_count, 1);
assertEquals(text.read(0).toArray().join(""), "ipsum");
assertEquals(text.line(0).toArray().join(""), "ipsum");Creates a SliceTree instance with optional initial text.
Syntax
new SliceTree(text?: string)Returns the total number of characters in the text content.
Syntax
get count(): numberExample
import { assertEquals } from "jsr:@std/assert";
import { SliceTree } from "jsr:@eu-ge-ne/slice-tree";
const text = new SliceTree("Lorem ipsum");
assertEquals(text.count, 11);Returns the number of lines in the text content.
Syntax
get line_count(): numberExample
import { assertEquals } from "jsr:@std/assert";
import { SliceTree } from "jsr:@eu-ge-ne/slice-tree";
const text = new SliceTree("Lorem\nipsum\ndolor\nsit\namet");
assertEquals(text.line_count, 5);Returns the text between the specified start (inclusive) and end (exclusive) positions.
Syntax
*read(start: number, end = Number.MAX_SAFE_INTEGER): Generator<string>Example
import { assertEquals } from "jsr:@std/assert";
import { SliceTree } from "jsr:@eu-ge-ne/slice-tree";
const text = new SliceTree("Lorem ipsum");
assertEquals(text.read(0).toArray().join(""), "Lorem ipsum");Returns the start index (inclusive) and the end index (exclusive) of the line at the specified index.
Syntax
line_range(index: number): readonly [number, number | undefined] | undefinedExample
import { assertEquals } from "jsr:@std/assert";
import { SliceTree } from "jsr:@eu-ge-ne/slice-tree";
const text = new SliceTree("Lorem\nipsum");
assertEquals(text.line_range(0), [0, 6]);Returns the content of the line at the specified index.
Syntax
*line(index: number): Generator<string>Example
import { assertEquals } from "jsr:@std/assert";
import { SliceTree } from "jsr:@eu-ge-ne/slice-tree";
const text = new SliceTree("Lorem\nipsum\ndolor\nsit\namet");
assertEquals(text.line(1).toArray().join(""), "ipsum\n");Inserts the given text at the specified index in the content.
Syntax
write(index: number, text: string): voidExample
import { assertEquals } from "jsr:@std/assert";
import { SliceTree } from "jsr:@eu-ge-ne/slice-tree";
const text = new SliceTree();
text.write(0, "Lorem ipsum");
assertEquals(text.read(0).toArray().join(""), "Lorem ipsum");Removes the text in the range from index (inclusive) to index + count (exclusive).
Syntax
erase(index: number, count: number): voidExample
import { assertEquals } from "jsr:@std/assert";
import { SliceTree } from "jsr:@eu-ge-ne/slice-tree";
const text = new SliceTree("Lorem ipsum");
text.erase(5, 6);
assertEquals(text.read(0).toArray().join(""), "Lorem");❯ deno bench bench/create.bench.ts
Check file:///Users/eug/Dev/github.com/eu-ge-ne/slice-tree/bench/create.bench.ts
CPU | Apple M4 Pro
Runtime | Deno 2.3.3 (aarch64-apple-darwin)
file:///Users/eug/Dev/github.com/eu-ge-ne/slice-tree/bench/create.bench.ts
benchmark time/iter (avg) iter/s (min … max) p75 p99 p995
---------------------- ----------------------------- --------------------- --------------------------
group Create
Creating a SliceTree 209.4 ns 4,776,000 (204.4 ns … 231.1 ns) 210.8 ns 218.3 ns 220.1 ns
Creating a string 88.2 ns 11,330,000 ( 86.6 ns … 102.7 ns) 88.6 ns 95.8 ns 99.6 ns
summary
Creating a SliceTree
2.37x slower than Creating a string❯ deno bench bench/write.bench.ts
Check file:///Users/eug/Dev/github.com/eu-ge-ne/slice-tree/bench/write.bench.ts
CPU | Apple M4 Pro
Runtime | Deno 2.3.3 (aarch64-apple-darwin)
file:///Users/eug/Dev/github.com/eu-ge-ne/slice-tree/bench/write.bench.ts
benchmark time/iter (avg) iter/s (min … max) p75 p99 p995
--------------------------------------------------- ----------------------------- --------------------- --------------------------
group Append x1000
Appending 1000 chars into a SliceTree 288.0 µs 3,472 (278.0 µs … 370.5 µs) 286.0 µs 351.5 µs 355.0 µs
Appending 1000 chars into a string 89.7 µs 11,150 ( 87.3 µs … 180.9 µs) 89.7 µs 126.6 µs 128.7 µs
summary
Appending 1000 chars into a SliceTree
3.21x slower than Appending 1000 chars into a string
group Append x10000
Appending 10000 chars into a SliceTree 3.2 ms 307.8 ( 3.1 ms … 4.0 ms) 3.3 ms 4.0 ms 4.0 ms
Appending 10000 chars into a string 887.4 µs 1,127 (874.4 µs … 1.1 ms) 885.3 µs 969.5 µs 1.0 ms
summary
Appending 10000 chars into a SliceTree
3.66x slower than Appending 10000 chars into a string
group Append x100000
Appending 100000 chars into a SliceTree 37.1 ms 26.9 ( 35.6 ms … 42.8 ms) 37.2 ms 42.8 ms 42.8 ms
Appending 100000 chars into a string 9.1 ms 110.3 ( 8.8 ms … 10.6 ms) 8.9 ms 10.6 ms 10.6 ms
summary
Appending 100000 chars into a SliceTree
4.10x slower than Appending 100000 chars into a string
group Write sequential x100
Writing 100 chars sequentially into a SliceTree 27.4 µs 36,500 ( 26.3 µs … 248.5 µs) 27.4 µs 32.4 µs 34.3 µs
Writing 100 chars sequentially into a string 19.1 µs 52,310 ( 18.0 µs … 163.2 µs) 19.0 µs 23.4 µs 26.2 µs
summary
Writing 100 chars sequentially into a SliceTree
1.43x slower than Writing 100 chars sequentially into a string
group Write sequential x1000
Writing 1000 chars sequentially into a SliceTree 306.5 µs 3,262 (298.0 µs … 563.7 µs) 308.1 µs 362.2 µs 417.5 µs
Writing 1000 chars sequentially into a string 1.1 ms 885.5 (726.6 µs … 1.6 ms) 1.3 ms 1.5 ms 1.5 ms
summary
Writing 1000 chars sequentially into a SliceTree
3.68x faster than Writing 1000 chars sequentially into a string
group Write sequential x10000
Writing 10000 chars sequentially into a SliceTree 3.5 ms 284.8 ( 3.4 ms … 4.0 ms) 3.5 ms 3.9 ms 4.0 ms
Writing 10000 chars sequentially into a string 283.1 ms 3.5 (271.2 ms … 297.1 ms) 285.4 ms 297.1 ms 297.1 ms
summary
Writing 10000 chars sequentially into a SliceTree
80.63x faster than Writing 10000 chars sequentially into a string
group Write interleaved x100
Writing 100 chars interleaved into a SliceTree 44.9 µs 22,250 ( 43.6 µs … 829.9 µs) 44.8 µs 50.2 µs 51.7 µs
Writing 100 chars interleaved into a string 19.8 µs 50,620 ( 18.2 µs … 150.2 µs) 19.8 µs 24.2 µs 26.7 µs
summary
Writing 100 chars interleaved into a SliceTree
2.27x slower than Writing 100 chars interleaved into a string
group Write interleaved x1000
Writing 1000 chars interleaved into a SliceTree 565.1 µs 1,769 (553.8 µs … 869.4 µs) 565.3 µs 692.3 µs 708.3 µs
Writing 1000 chars interleaved into a string 1.4 ms 719.0 (821.7 µs … 1.9 ms) 1.6 ms 1.8 ms 1.9 ms
summary
Writing 1000 chars interleaved into a SliceTree
2.46x faster than Writing 1000 chars interleaved into a string
group Write interleaved x10000
Writing 10000 chars interleaved into a SliceTree 6.9 ms 144.4 ( 6.8 ms … 7.4 ms) 6.9 ms 7.4 ms 7.4 ms
Writing 10000 chars interleaved into a string 299.2 ms 3.3 (295.7 ms … 302.1 ms) 300.7 ms 302.1 ms 302.1 ms
summary
Writing 10000 chars interleaved into a SliceTree
43.20x faster than Writing 10000 chars interleaved into a string❯ deno bench bench/erase.bench.ts
CPU | Apple M4 Pro
Runtime | Deno 2.3.3 (aarch64-apple-darwin)
file:///Users/eug/Dev/github.com/eu-ge-ne/slice-tree/bench/erase.bench.ts
benchmark time/iter (avg) iter/s (min … max) p75 p99 p995
----------------------------------------------------- ----------------------------- --------------------- --------------------------
group Erase sequential x10000
Erasing 10000 chars sequentially from a SliceTree 1.6 ms 639.7 ( 1.5 ms … 2.0 ms) 1.6 ms 1.8 ms 1.9 ms
Erasing 10000 chars sequentially from a string 38.7 µs 25,870 ( 36.8 µs … 118.9 µs) 37.7 µs 73.6 µs 75.8 µs
summary
Erasing 10000 chars sequentially from a SliceTree
40.44x slower than Erasing 10000 chars sequentially from a string
group Erase sequential x100000
Erasing 100000 chars sequentially from a SliceTree 20.4 ms 49.1 ( 19.7 ms … 21.4 ms) 20.8 ms 21.4 ms 21.4 ms
Erasing 100000 chars sequentially from a string 387.4 µs 2,581 (369.2 µs … 661.1 µs) 401.4 µs 484.2 µs 648.0 µs
summary
Erasing 100000 chars sequentially from a SliceTree
52.54x slower than Erasing 100000 chars sequentially from a string
group Erase sequential x1000000
Erasing 1000000 chars sequentially from a SliceTree 269.8 ms 3.7 (259.8 ms … 277.8 ms) 273.4 ms 277.8 ms 277.8 ms
Erasing 1000000 chars sequentially from a string 3.9 ms 257.6 ( 3.8 ms … 5.0 ms) 3.9 ms 5.0 ms 5.0 ms
summary
Erasing 1000000 chars sequentially from a SliceTree
69.52x slower than Erasing 1000000 chars sequentially from a string