FSKalc/Readme.md

Reference

The following is an informal overview of FSKalc's capabilties.

Expressions

Number literal

Example:

8.5

Variable read

Example:

a

Will print an error message if variable is undefined. The ans variable implicitly refers to the result of the last expression statement.

Parentheses for precedence

Example:

(5+6)*7

Parentheses increase precedence.

Parentheses for function calls

Parentheses can also represent function calls, if they contain more than one element (separated by a space).

Example:

(sin 50)

Arithmetic operators

The following operators are valid, in decreasing precedence:

• ^ power; right associative
• - unary negation; note that multiple negations next to eachother are invalid!
• factor precedence:
  • * multiplication; left associative
  • / division; left associative
  • // integer (flooring) division; left associative
  • % modulo; left associative
• term precedence:
  • + addition; left associative
  • - subtraction; left associative

Statements

Statements are the top level construct. Every line in an FSKalc program has to be a statement.

Expression statement

Any valid expression is also a valid statement. The result of expression statements is printed to the screen, and also assigned to the variable names ans.

Variable assignments

Variable assignments have the following syntax:

identifier = expression

Where the identifier is a string of characters containing only letters and underscores.

Existing variables or functions can be overwritten by new variables/functions.

Function declaration

Function declaration has the following syntax, demonstrated by an example below.

double x = x * 2

Warning! as there are no scopes in FSKalc, passing arguments to functions will modify the global scope.

Builtins

Builtin Constants

• pi
• tau (pi * 2)
• e (euler's number)
• inf (infinity)
• nan (not a number)

Builtin Functions

• sin, cos, tan - they take 1 argument, in radians
• arcsin, arccos, arctan - they take 1 argument, they return in radians
• sqrt - returns square root, optional second argument is the power, default of 2
• log - logarithm, optional second argument is the base, default of 10
• ln - natural logarithm
• exp - returns e to the power of the argument

Comments

Comments can be inside matching (*, *) parentheses.