Crafting Interpreters

Builtin Types

• Number - 64 bit float
• Str
• Bool
• Array
• Function
• Nil

Native Functions

In case of errors or invalid arguments, a global error variable named "errString" is set with the error message and the function returns nil. Otherwise, the global error variable is set to nil.

1. Clock() -> Number

   Returns the current epoch in milliseconds.

2. Print(Str)

   Prints the given string to the output.

3. ReadNumber(String) -> Number

   Reads a number from the input, displaying the given string as a prompt.

4. ReadString(String) -> Str

   Reads a string from the input, displaying the given string as a prompt.

5. ReadBool() -> Bool

   Reads a boolean from the input.

6. TypeOf(Any) -> String

   Returns the type of the given value.

7. ToString(Any) -> String

   Converts the given value to a string.

8. ToNumber(String) -> Number

   Converts the given string to a number.

9. StringAt(String, Number) -> String

   Returns the character at the given index in the string.

10. StrLen(String) -> Number

    Returns the length of the given string.

11. ArrLen(String) -> Number

    Returns the length of the given array.

12. Ceil(Number) -> Number

    Returns the smallest integer greater than or equal to the given number.

13. Floor(Number) -> Number

    Returns the largest integer less than or equal to the given number.

14. Abs(Number) -> Number

    Returns the absolute value of the given number.

15. Rand() -> Number

    Returns a 32-bit unsigned integer ( as Number )

16. Sort(Array)

    Sorts an arrray of numbers in ascending order. If the array has non-numbers, it's an error.

17. IndexOf(Array, Any) -> Number

    Returns the index of the given value in the array. If the value is not found, returns the length of the array.