azusfin / basic-jsmath

A lightweight math parsing library to deal with some basic maths

basic-jsmath

A lightweight math parsing library to deal with some basic maths

Table Of Contents

• Methods
  • Parsing
  • Calculate
  • Function
• Specifications
  • Operations
    • Operation
  • Block
    • Number Block
    • Variable Block
    • Function Block
  • Operators
  • Variables
    • Variable
• Helpers
  • Default Variables
  • Default Functions

Methods

Parsing

• parse(calculation: string) -> Operations

  Parse math syntax into operations, refer to specifications for more info

  Examples:

  // This will parse to operations which
  // can be used in execute method
  const ops = parse("1 + 2")

Calculate

• execute(
    operations: Operations,
    variables: Variables = {},
    strict: boolean = true
  ) -> number

  Execute math operations and will return the result as number

  Examples:

  // Will execute the previously parsed operations and return '3'
  const ops = parse("1 + 2")
  execute(ops)
  
  // Using variables, will return '3'
  const opsWithVars = parse("a + b")
  execute(opsWithVars, { a: 1, b: 2 })
  
  // Disable error when failed to load variables, will return '0' because no variables defined
  execute(opsWithVars, {}, false)

• math(
    calculation: string,
    variables: Variables = {},
    strict: boolean = true
  ) -> number

  Parse and execute operations and will return the result as number

  Examples:

  // Both works the same
  
  // The long path
  const ops = parse("1 + 1")
  execute(ops)
  
  // The short path
  math("1 + 1")

Function

• wrap(
    operations: Operations,
    varName: string,
    variables: Variables = {},
    strict: boolean = true
  ) -> ((val: number) => number)

  Wrap the operations into a javascript function

  Examples:

  // Parse the operations of calculating sinus, we use x as the input variable
  const sinOps = parse("sin(deg(x))")
  
  // Notice how we use "x" as the varName because our input variable is "x"
  const sin = wrap(sinOps, "x")
  
  // Will return 1
  sin(90)

• wrapMath(
    calculation: string,
    varName: string,
    variables: Variables = {},
    strict: boolean = true
  ) -> ((val: number) => number)

  Parse and wrap the operations into a javascript function

  Examples:

  // Both works the same
  
  // The long path
  const sinOps = parse("sin(deg(x))")
  const sin = wrap(sinOps, "x")
  
  // The short path
  const sin = wrapMath("sin(deg(x))", "x")
  
  // Both will return the same value
  sin(90)

Specifications

Operations

(Operations | Operation)[]

Operation

{ prev: Block, next: Block, operator: Operators }

Block

Number Block | Variable Block | Function Block

Number Block

{ type: 0, value: number }

Variable Block

{ type: 1, name: string }

Function Block

{ type: 2, name: string, params: Operations[] }

Operators

Operator	Description
+	Summation of numbers, 1 + 2 = 3
-	Subtraction of numbers, 3 - 2 = 1
*	Multiplication of numbers, 2 * 2 = 4
/	Division of numbers, 10 / 2 = 5
%	Modulus of numbers, 7 % 2 = 1
^	Exponentiation of number, 3 ^ 3 = 27

Variables

Record<string, Variable>

/**
 * Variables name are case-sensitive, X ≠ x
 */

// Variable only
const vars = {
    x: 100
}

// Function only
const vars = {
    x: (x) => x * x / x ** 1 / x
}

// Variable and function
const vars = {
    x: [100, (x) => x * x / x ** 1 / x]
}

Variable

number | ((...values: number[]) -> number) | [number, (...values: number[]) -> number]

Helpers

Default Variables

Variable	Description
PI	The ratio of the circumference of a circle to its diameter, 3.141592653589793
SQRT2	Square root of 2, 1.4142135623730951

Default Functions

Function	Description
round or ROUND	Round the provided number into nearest integer, round(2.99999) = 3
toFIxed or TOFIXED	Round into nearest fixed decimal position, toFixed(8.384444, 2) = 8.38
sqrt or SQRT	Square root of number, sqrt(16) = 4
cbrt or CBRT	Cube root of number, cbrt(125) = 5
nthrt or NTHRT	Nth root of number, nthrt(1296, 4) = 6
sin or SIN	Calculate sinus of number, sin(1.5707963267948966) = 1
cos or COS	Calculate cosinus of number, cos(0) = 1
tan or TAN	Calculate tangent of number, tan(0.7853981633974483) = 1
deg or DEG	Transform degree into radiant, deg(90) = 1.5707963267948966
rad or RAD	Transform radiant into degree, rad(1.5707963267948966) = 90