I'm trying to make a console-based program that makes use of ANSI escape codes with GNU Smalltalk. I can't seem to figure out how to go about printing a string object formatted with ANSI escape codes. I've tried the following.
'\x1b[31mHi' displayNl
This prints the entire string, including the escape code, without any formatting. I would have expected this to print "Hi" in red (and then everything else in the console after that, as I didn't reset the color.)
After googling a bit, I was able to find a couple issues on mailing lists where people were trying to produce things like newlines using "\n". Most of the answers were using the Transcript object's cr method, but I didn't find anything about colors in the textCollector class.
It looks like it shouldn't be all that hard to create my own module in C to achieve this functionality, but I'd like to know if there's a better way first.
I'm aware of the ncurses bindings, but I'm not sure that'd be practical for just making certain pieces of text in the program colored. So, is there a standard way of outputting colored text to the terminal in GNU Smalltalk using ANSI escape sequences?
Ended up getting an answer on the GNU Smalltalk mailing list. Looks like you can use an interpolation operator to achieve this.
For example ('%1[31mHi' % #($<16r1B>)) displayNl. would change the color to red, and ('%1[34mHi' % #($<16r1B>)) displayNl. would change the color to blue.
Basically, the % operator looks for a sequences that look like "%(number)" and replaces them with the objects in the array to the right of the operator. In our case, the array has one item, which is the ascii escape character in hexadecimal. So the "%1" in "%1[31mHi' is being replaced with the escape character, and then printed.
(This answer was stolen almost verbatim from Paolo on the GNU Smalltalk mailing list.)