lua-users home
lua-l archive

[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index] [Thread Index]

Hello Lua Hackers,

2010/9/16 David Kastrup <>
> In the view point of the parser, the logical operator 'and' has
> higher priority than 'or', but, for programmers, a ternary operator
> must have lower priority than logical operator.


Because, the first operand of a ternary operator is a conditional _expression_.  In a conditional _expression_, we want to use logical operators frequently, and unnecessary parenthesis are unwelcome.
And, the second operand of a ternary operator (which is between ? :, then/else, and/or etc.) is an independent _expression_, so if there is an operator which priority is lower than a ternary operator, it is very confusing.  For example, and if a ternary operator is ? :, and its priority is equal to 'and' and higher than 'or', how to process following code.

x = A ? B or C : D

Thank you,
Ryota Hirose