Logical Expressions

Comparison Operators

Operators relating to comparison are:

• ==: Strict equality comparison operator

• !=: Strict inequality comparison operator

• >: "Greater Than" comparison operator

• <: "Less Than" comparison operator

• >=: "Greater Than or Equal To" comparison operator

• <=: "Less Than or Equal To" comparison operator

In JavaScript, equality comparison have two versions: == and === which the latter one is strict version of the equality comparison.

Hence, when using == in Wyrd, it will compiled into strict version of the code:

"Hello world" == "Hello world"

"Hello world" === "Hello world"

The returned result of logical operation will always return data of type Bool.

Comparison Operators Accept Identical Types Only

When comparing two different type of data, Wyrd will throw error message:

123 == "123"

ParserError: Invalid operation for operator `==` with operands of type `Num` and `Str`

TODO: This behavior may be override by using "operator overloading", currently this feature hasn't implemented yet

Logical Chaining

Sometimes we would want more than one comparisons chained together using AND/OR or NOT relationships. Thus, Wyrd provides three keywords and, or and not to chain logical expressions. And of course, these keywords will be compiled in JavaScript which maps to &&, || and ! operators.

True and False or not False
not False and True
not (False or True) and False

And of course, you can chain not only Bool type values, you can chain multiple comparison operations:

3 + 1 > 2
5 * 3 < 15 - 6 * 8
11 >= 7 + 7 or 3 <= (6 + 2) / 3
8 / (4 * 2) > 3 and not 1 + 2 * 3 == 7 or a + b / c * d != w - x * y

TODO: Handle Logical Expressions Where AND/OR and NOT Operation Should Only Accept Boolean Values