missing_x_msg function

(Internal) If the x argument does not exist for match_on, fullmatch, or pairmatch, use this function to print a helpful message.

missing_x_msg(x_str, data_str, ...)

Arguments

• x_str: x as a string of code, usually deparse(substitute(x))
• data_str: data arg as string of code
• ...: will look for 'z = ' in the extra args of caller

Returns

string a helpful error message

Author(s)

Josh Buckner