API v3.0.x


npm: npm install @hapi/formula

yarn: yarn add @hapi/formula


new Formula.Parser(formula, [options])

Creates a new formula parser object where:

  • formula - the formula string to parse.
  • options - optional settings:
    • constants - a hash of key-value pairs used to convert constants to values.
    • tokenRx - a regular expression used to validate token variables.
    • reference - a variable resolver factory function with signature function(variable) which returns a function with signature function(context) returning the resolved variable.
    • functions - a hash of key-value pairs used to resolve formula functions.


Evaluate the formula where:

  • context - optional object with runtime formula context used to resolve variables.

Returns the string or number outcome of the resolved formula.