/fast-formula-parser

Parse and evaluate MS Excel formula in javascript.

Primary LanguageJavaScriptMIT LicenseMIT

GitHub npm (tag) npm Coverage Status Build Status

A Fast Excel Formula Parser & Evaluator

A fast and reliable excel formula parser in javascript. Using LL(1) parser.

Demo

Documentation

Grammar Diagram

Supports 280 Formulas

ABS, ACOS, ACOSH, ACOT, ACOTH, ADDRESS, AND, ARABIC, AREAS, ASC, ASIN, ASINH, ATAN, ATAN2, ATANH, AVEDEV, AVERAGE, AVERAGEA, AVERAGEIF, BAHTTEXT, BASE, BESSELI, BESSELJ, BESSELK, BESSELY, BETA.DIST, BETA.INV, BIN2DEC, BIN2HEX, BIN2OCT, BINOM.DIST, BINOM.DIST.RANGE, BINOM.INV, BITAND, BITLSHIFT, BITOR,
BITRSHIFT, BITXOR, CEILING, CEILING.MATH, CEILING.PRECISE, CHAR, CHISQ.DIST, CHISQ.DIST.RT, CHISQ.INV, CHISQ.INV.RT, CHISQ.TEST, CLEAN, CODE, COLUMN, COLUMNS, COMBIN, COMBINA, COMPLEX, CONCAT, CONCATENATE, CONFIDENCE.NORM, CONFIDENCE.T, CORREL, COS, COSH, COT, COTH, COUNT, COUNTIF, COVARIANCE.P,
COVARIANCE.S, CSC, CSCH, DATE, DATEDIF, DATEVALUE, DAY, DAYS, DAYS360, DBCS, DEC2BIN, DEC2HEX, DEC2OCT, DECIMAL, DEGREES, DELTA, DEVSQ, DOLLAR, EDATE, ENCODEURL, EOMONTH, ERF, ERFC, ERROR.TYPE, EVEN, EXACT, EXP, EXPON.DIST, F.DIST, F.DIST.RT, F.INV, F.INV.RT, F.TEST, FACT, FACTDOUBLE, FALSE, FIND, FINDB,
FISHER, FISHERINV, FIXED, FLOOR, FLOOR.MATH, FLOOR.PRECISE, FORECAST, FORECAST.LINEAR, FREQUENCY, GAMMA, GAMMA.DIST, GAMMA.INV, GAMMALN, GAMMALN.PRECISE, GAUSS, GCD, GEOMEAN, GESTEP, GROWTH, HARMEAN, HEX2BIN, HEX2DEC, HEX2OCT, HLOOKUP, HOUR, HYPGEOM.DIST, IF, IFERROR, IFNA, IFS, IMABS, IMAGINARY, IMARGUMENT,
IMCONJUGATE, IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMDIV, IMEXP, IMLN, IMLOG10, IMLOG2, IMPOWER, IMPRODUCT, IMREAL, IMSEC, IMSECH, IMSIN, IMSINH, IMSQRT, IMSUB, IMSUM, IMTAN, INDEX, INT, INTERCEPT, ISBLANK, ISERR, ISERROR, ISEVEN, ISLOGICAL, ISNA, ISNONTEXT, ISNUMBER, ISO.CEILING, ISOWEEKNUM, ISREF, ISTEXT,
KURT, LCM, LEFT, LEFTB, LN, LOG, LOG10, LOGNORM.DIST, LOGNORM.INV, LOWER, MDETERM, MID, MIDB, MINUTE, MMULT, MOD, MONTH, MROUND, MULTINOMIAL, MUNIT, N, NA, NEGBINOM.DIST, NETWORKDAYS, NETWORKDAYS.INTL, NORM.DIST, NORM.INV, NORM.S.DIST, NORM.S.INV, NOT, NOW, NUMBERVALUE, OCT2BIN, OCT2DEC, OCT2HEX, ODD, OR,
PHI, PI, POISSON.DIST, POWER, PRODUCT, PROPER, QUOTIENT, RADIANS, RAND, RANDBETWEEN, REPLACE, REPLACEB, REPT, RIGHT, RIGHTB, ROMAN, ROUND, ROUNDDOWN, ROUNDUP, ROW, ROWS, SEARCH, SEARCHB, SEC, SECH, SECOND, SERIESSUM, SIGN, SIN, SINH, SQRT, SQRTPI, STANDARDIZE, SUM, SUMIF, SUMPRODUCT, SUMSQ, SUMX2MY2, 
SUMX2PY2, SUMXMY2, T, T.DIST, T.DIST.2T, T.DIST.RT, T.INV, T.INV.2T, TAN, TANH, TEXT, TIME, TIMEVALUE, TODAY, TRANSPOSE, TRIM, TRUE, TRUNC, TYPE, UNICHAR, UNICODE, UPPER, VLOOKUP, WEBSERVICE, WEEKDAY, WEEKNUM, WEIBULL.DIST, WORKDAY, WORKDAY.INTL, XOR, YEAR, YEARFRAC

Size: 291KB Minified, 81KB Gzipped+Minified

Background

Inspired by XLParser and the paper "A Grammar for Spreadsheet Formulas Evaluated on Two Large Datasets" by Efthimia Aivaloglou, David Hoepelman and Felienne Hermans.

Note: The grammar in my implementation is different from theirs. My implementation gets rid of ambiguities to boost the performance.

What is not supported:

  • External reference
    • Anything with [ and ]
  • Ambiguous old styles
    • Sheet name contains :, e.g. SUM('1003:1856'!D6)
    • Sheet name with space that is not quoted, e.g. I am a sheet!A1
  • SUM(Sheet2:Sheet3!A1:C3)
  • You tell me

Performance

  • The expected performance is at least 3x faster than the optimized formula-parser.

Dependency

  • Chevrotain , thanks to this great parser building toolkit.

Examples

  • Install

    npm i fast-formula-parser
# or using yarn
yarn add fast-formula-parser

  • Import

    const FormulaParser = require('fast-formula-parser');
const {FormulaHelpers, Types, FormulaError, MAX_ROW, MAX_COLUMN} = FormulaParser;
// or
import FormulaParser, {FormulaHelpers, Types, FormulaError, MAX_ROW, MAX_COLUMN} from 'fast-formula-parser';

    UMD minified build is also provides:

    <script src="/node_modules/fast-formula-parser/build/parser.min.js"> </script>

  • Basic Usage

    const data = [
  // A  B  C
    [1, 2, 3], // row 1
    [4, 5, 6]  // row 2
];

const parser = new FormulaParser({

    // External functions, this will override internal functions with same name
    functions: {
        CHAR: (number) => {
            number = FormulaHelpers.accept(number, Types.NUMBER);
            if (number > 255 || number < 1)
                throw FormulaError.VALUE;
            return String.fromCharCode(number);
        }
    },

    // Variable used in formulas (defined name)
    // Should only return range reference or cell reference
    onVariable: (name, sheetName) => {
        // If it is a range reference (A1:B2)
        return {
            sheet: 'sheet name',
            from: {
                row: 1,
                col: 1,
            },
            to: {
                row: 2,
                col: 2,
            }
        };
        // If it is a cell reference (A1)
        return {
            sheet: 'sheet name',
            row: 1,
            col: 1
        }
    },

    // retrieve cell value
    onCell: ({sheet, row, col}) => {
        // using 1-based index
        // return the cell value, see possible types in next section.
        return data[row - 1][col - 1];
    },

    // retrieve range values
    onRange: (ref) => {
        // using 1-based index
        // Be careful when ref.to.col is MAX_COLUMN or ref.to.row is MAX_ROW, this will result in
        // unnecessary loops in this approach.
        const arr = [];
        for (let row = ref.from.row; row <= ref.to.row; row++) {
            const innerArr = [];
            if (data[row - 1]) {
                for (let col = ref.from.col; col <= ref.to.col; col++) {
                    innerArr.push(data[row - 1][col - 1]);
                }
            }
            arr.push(innerArr);
        }
        return arr;
    }
});

// position is required for evaluating certain formulas, e.g. ROW()
const position = {row: 1, col: 1, sheet: 'Sheet1'};

// parse the formula, the position of where the formula is located is required
// for some functions.
console.log(parser.parse('SUM(A:C)', position));
// print 21

// you can specify if the return value can be an array, this is helpful when dealing
// with an array formula
console.log(parser.parse('MMULT({1,5;2,3},{1,2;2,3})', position, true));
// print [ [ 11, 17 ], [ 8, 13 ] ]

  • Custom Async functions

    Remember to use await parser.parseAsync(...) instead of parser.parse(...)

    const position = {row: 1, col: 1, sheet: 'Sheet1'};
const parser = new FormulaParser({
    onCell: ref => {
        return 1;
    },
    functions: {
        DEMO_FUNC: async () => {
            return [[1,2,3],[4,5,6]];
        }
    },
});
console.log(await parser.parseAsync('A1 + IMPORT_CSV())', position));
// print 2
console.log(await parser.parseAsync('SUM(DEMO_FUNC(), 1))', position));
// print 22

  • Custom function requires parser context (e.g. location of the formula)

    const position = {row: 1, col: 1, sheet: 'Sheet1'};
const parser = new FormulaParser({
    functionsNeedContext: {
        // the first argument is the context
        // the followings are the arguments passed to the function
        ROW_PLUS_COL: (context, ...args) => {
             return context.position.row + context.position.col;
        }
    },
});
console.log(await parser.parseAsync('SUM(ROW_PLUS_COL(), 1)', position));
// print 3

  • Parse Formula Dependency

    This is helpful for building dependency graph/tree.

    import {DepParser} from 'fast-formula-parser';
const depParser = new DepParser({
    // onVariable is the only thing you need provide if the formula contains variables
    onVariable: variable => {
        return 'VAR1' === variable ? {from: {row: 1, col: 1}, to: {row: 2, col: 2}} : {row: 1, col: 1};
    }
});

// position of the formula should be provided
const position = {row: 1, col: 1, sheet: 'Sheet1'};

// Return an array of references (range reference or cell reference)
// This gives [{row: 1, col: 1, sheet: 'Sheet1'}]
depParser.parse('A1+1', position);

// This gives [{sheet: 'Sheet1', from: {row: 1, col: 1}, to: {row: 3, col: 3}}]
depParser.parse('A1:C3', position);

// This gives [{from: {row: 1, col: 1}, to: {row: 2, col: 2}}]
depParser.parse('VAR1 + 1', position);

// Complex formula
depParser.parse('IF(MONTH($K$1)<>MONTH($K$1-(WEEKDAY($K$1,1)-(start_day-1))-IF((WEEKDAY($K$1,1)-(start_day-1))<=0,7,0)+(ROW(O5)-ROW($K$3))*7+(COLUMN(O5)-COLUMN($K$3)+1)),"",$K$1-(WEEKDAY($K$1,1)-(start_day-1))-IF((WEEKDAY($K$1,1)-(start_day-1))<=0,7,0)+(ROW(O5)-ROW($K$3))*7+(COLUMN(O5)-COLUMN($K$3)+1))', position);
// This gives the following result
const result = [
    {
        "col": 11,
        "row": 1,
        "sheet": "Sheet1",
    },
    {
        "col": 1,
        "row": 1,
        "sheet": "Sheet1",
    },
    {
        "col": 15,
        "row": 5,
        "sheet": "Sheet1",
    },
    {
        "col": 11,
        "row": 3,
        "sheet": "Sheet1",
    },
];

Formula data types in JavaScript

The following data types are used in excel formulas and these are the only valid data types a formula or a function can return.

  • Number (date uses number): 1234
  • String: 'some string'
  • Boolean: true, false
  • Array: [[1, 2, true, 'str']]
  • Range Reference: (1-based index) 
    const ref = {
    sheet: String,
    from: {
        row: Number,
        col: Number,
    },
    to: {
        row: Number,
        col: Number,
    },
}
  • Cell Reference: (1-based index) 
    const ref = {
    sheet: String,
    row: Number,
    col: Number,
}
  • Union (e.g. (A1:C3, E1:G6))
  • FormulaError
    • FormulaError.DIV0: #DIV/0!
    • FormulaError.NA: #N/A
    • FormulaError.NAME: #NAME?
    • FormulaError.NULL: #NULL!
    • FormulaError.NUM: #NUM!
    • FormulaError.REF: #REF!
    • FormulaError.VALUE: #VALUE!

Types Definition

Comming soon

Error handling

  • Lexing/Parsing Error

    Error location is available at error.details.errorLocation

    try {
    parser.parse('SUM(1))', position);
} catch (e) {
    console.log(e);
    // #ERROR!:
    // SUM(1))
    //       ^
    // Error at position 1:7
    // Redundant input, expecting EOF but found: )

    expect(e).to.be.instanceof(FormulaError);
    expect(e.details.errorLocation.line).to.eq(1);
    expect(e.details.errorLocation.column).to.eq(7);
    expect(e.name).to.eq('#ERROR!');
    expect(e.details.name).to.eq('NotAllInputParsedException');
}
  • Error from internal/external functions or unexpected error from the parser

    The error will be wrapped into FormulaError. The exact error is in error.details.

    const parser = new FormulaParser({
    functions: {
        BAD_FN: () => {
            throw new SyntaxError();
        }
    }
});

try {
    parser.parse('SUM(1))', position);
} catch (e) {
    expect(e).to.be.instanceof(FormulaError);
    expect(e.name).to.eq('#ERROR!');
    expect(e.details.name).to.eq('SyntaxError');
}

Thanks

  • JetBrains