bibtex-parse

Parse BibTeX to JSON.

npm install bibtex-parse

Example

const bibtexParse = require('bibtex-parse');
const fs = require('fs');
const bibtex = fs.readFileSync('example.bib', 'utf8');
bibtexParse.entries(bibtex);

example.bib:

@preamble{"Reference list"}
@string{ian = "Brown, Ian"}
@string{jane = "Woods, Jane"}
%references
@inproceedings{Smith2009,
  author=jane,
  year=2009,
  month=dec,
  title={{Quantum somethings}},
  journal={Journal of {B}lah}
}

@book{IP:1990,
author = ian # " and " # jane,
year = {1990},
title = {Methods for Research}
}

output:

[
  {
    "key": "Smith2009",
    "type": "inproceedings",
    "AUTHOR": "Woods, Jane",
    "YEAR": 2009,
    "MONTH": "December",
    "TITLE": "Quantum somethings",
    "JOURNAL": "Journal of Blah"
  },
  {
    "key": "IP:1990",
    "type": "book",
    "AUTHOR": "Brown, Ian and Woods, Jane",
    "YEAR": "1990",
    "TITLE": "Methods for Research"
  }
]

Note: fields are always output in capitals to distinguish from build in attributes (key and type).

Abstract Syntax Tree

To get the AST, use:

bibtexParse.parse(bibtex, options);

Where bibtex is a string representing bibtex to be parsed, and options an object with any of the following:

• number: tells the parser how numbers should be returned.
  • number: "auto" (default): return a JavaScript number, unless over MAX_SAFE_INTEGER (9007199254740991), in which case a BigInt is returned.
  • number: "number": always return a JavaScript number, even if over MAX_SAFE_INTEGER (in which case the precision will be lost).
  • number: "bigint": always return a BigInt.
  • number: "string": return number as a string.

This will return an array of items. There are four types of item:

• string: { itemtype: 'string', name, value, datatype, enclosed }
• preamble: { itemtype: 'preamble', value, datatype, enclosed }
• comment: { itemtype: 'comment', comment }
• entry: { itemtype: 'entry', type, key, enclosed, fields },
  • type: e.g. article, inproceedings, book
  • key: the unique identifier for the entry
  • fields: e.g. title, year [{ name: 'year', value: 2001, datatype: 'number' }, ...]

Datatype can be one of the following:

• number: an integer number
• identifier: a string variable name
• braced: a value which was enclosed in curly braces
• quoted: a value which was enclosed in double quotes
• concatinate: in which case the corresponding value property will be an array [{ datatype, value }, ...]
• null: used when no value has been assigned, e.g. @string{a}
• unenclosed: used when a preamble has not been properly enclosed (e.g @preamble{this isn't enclosed}).

Enclosed can be one of the following:

• braces - when item is enclosed in curly braces (e.g. @string{a = 1})
• parentheses - when item is enclosed in brackets (e.g. @string(a = 1))

[
  {
    "itemtype": "preamble",
    "enclosed": "braces",
    "value": "Reference list",
    "datatype": "quoted"
  },
  { "itemtype": "comment", "comment": "\n" },
  {
    "itemtype": "string",
    "name": "ian",
    "value": "Brown, Ian",
    "datatype": "quoted"
  },
  { "itemtype": "comment", "comment": "\n" },
  {
    "itemtype": "string",
    "name": "jane",
    "value": "Woods, Jane",
    "datatype": "quoted"
  },
  { "itemtype": "comment", "comment": "\n%references\n" },
  {
    "itemtype": "entry",
    "type": "inproceedings",
    "enclosed": "braces",
    "key": "Smith2009",
    "fields": [
      { "name": "author", "value": "jane", "datatype": "identifier" },
      { "name": "year", "value": 2009, "datatype": "number" },
      { "name": "month", "value": "dec", "datatype": "identifier" },
      {
        "name": "title",
        "value": "{Quantum somethings}",
        "datatype": "braced"
      },
      { "name": "journal", "value": "Journal of {B}lah", "datatype": "braced" }
    ]
  },
  { "itemtype": "comment", "comment": "\n\n" },
  {
    "itemtype": "entry",
    "type": "inproceedings",
    "enclosed": "braces",
    "key": "Smith2009",
    "fields": [
      { "name": "author", "value": "jane", "datatype": "identifier" },
      { "name": "year", "value": 2009, "datatype": "number" },
      { "name": "month", "value": "dec", "datatype": "identifier" },
      {
        "name": "title",
        "value": "{Quantum somethings}",
        "datatype": "braced"
      },
      { "name": "journal", "value": "Journal of {B}lah", "datatype": "braced" }
    ]
  }
]

Resources

• A summary of BibTex - http://maverick.inria.fr/~Xavier.Decoret/resources/xdkbibtex/bibtex_summary.html
• ORCID bibtex parse library - https://github.com/ORCID/bibtexParseJs