Disabling multi-line expressions?

[blenderskool]

Hi, is there a way to disable the execution of multi-line expressions(that use ; or \n to separate different lines). I couldn't find any option in the docs for this and I don't have much idea about how mathjs is handling this internally.

After disabling multi-line expressions, I'd expect mathjs to execute only the first line of the multi-line expression or just throw a syntax error and not execute any statement.

[josdejong]

There is no built-in option, but you can do some pre/post processing to throw an error or something in case the user entered a multi line expression. Some ideas:

• Just execute any expression. Check if the returned result is a ResultSet, if so, throw an error
• Parse the expression. If the parsed tree is a BlockNode, throw an error. If not, execute the parsed expression.

[blenderskool]

Thanks, @josdejong. I also considered using a regular expression to check if ; or \n appear in the expression(also taking into account for quoted strings where the characters are fine).
I'll try the approaches you shared.

[josdejong]

You indeed have to be careful with a regex approach: like you say, these characters can be part of a string, and also, ; is a valid character used in matrices like [1, 2; 3, 4].