Comparison operators `== / >= /...` return `bool`.
Logical operators `&& ||` return bool.
Constants `true` and `false` have the `bool` type.
Lots of stdlib functions return `bool`, not `int`.
Operator `!x` supports both `int` and `bool`.
Condition of `if` accepts both `int` and `bool`.
Arithmetic operators are restricted to integers.
Logical `&&` and `||` accept both `bool` and `int`.
No arithmetic operations with bools allowed (only bitwise and logical).
Lots of changes, actually. Most noticeable are:
- traditional //comments
- #include -> import
- a rule "import what you use"
- ~ found -> !found (for -1/0)
- null() -> null
- is_null?(v) -> v == null
- throw is a keyword
- catch with swapped arguments
- throw_if, throw_unless -> assert
- do until -> do while
- elseif -> else if
- drop ifnot, elseifnot
- drop rarely used operators
A testing framework also appears here. All tests existed earlier,
but due to significant syntax changes, their history is useless.