SGF Tree Parser

An SGF is basically a text encoding of a tree data structure, and its grammar is described here.

Usage

Basic parsing:

import { SgfTree } from "../sgf_tree"

const sgfTree = SgfTree.parseSgf("...")

The tree's type is equivalent to this type in the end:

type SgfTree = {
  data: SgfProperties
  children: SgfTree[]
}

Some useful methods:

tree.toSgf()
tree.toJson()
tree.toPrettyJsonString()
tree.toArray()

Typical SGF tree operations:

const newNode = new SgfTree({ B: "jj" }, [])

sgfTrees.add(newNode, {
  down: 3,
  right: 3,
})

sgfTrees.remove({ down: 3, right: 2 })

sgfTrees.shift({ down: 3, right: 3 }, true)

You can find out more about how to use these methods from the test files.

References

• Go Pattern Search
• Sabaki's SGF Parser
• SGF Docs
  • Red Bean - SGF
  • CWI - SGF Format
• Stack Overflow - How to Parse SGF Metadata with JS Regexes
• Stack Overflow - Recursive Regex for Parsing SGF with JS
• Peg.js - A package for parsing any grammar
• LaTeX Stack Exchange - Parsing the Main Branch of Single-Branched SGF Files (with Regex?)