a "consuming-generator"

[Skaperen]

a "filter" in the general computer science terminology is a thing or object (could be a function, a class, a command, a module, a server,a machine, a robot, pretty much anything) that takes some input and produces some output that is based on the input. common filters do things like translation, recoding, compression, a so forth. many functions are considered to be filters in this sense, such as hex() in python.

what i was doing in C was trying to make the construction of more complex filters easier to interface with, especially filters that might need more input than initially given to it to give more output. compression often encounters this where one chunk of input has the beginning of a long run of spaces an its end and the next chunk has more spaces. the output will eventually have a code that represents that run of spaces. this is a "stateful filter" because it is keeping some of that data for a while between accesses. that kind of thing is hard to do well in just about any language. it's why unix shells do pipelines (commands or executable programs being the filters).