What does "emit" mean in general computer science terms? -

i stumbled on appears generally-known compsci keyword, "emit". can't find clear definition of in general computer science terms, nor specific definition of "emit()" function or keyword in specific programming language.

i found here, reading on mapreduce:

https://en.wikipedia.org/wiki/mapreduce

the context of additional searches show has signaling and/or events. seems assumed reader know "emit" , does. example, article on mapreduce patterns:

https://highlyscalable.wordpress.com/2012/02/01/mapreduce-patterns/

there's no mention of "emit" doing, there calls it. must different other forms of returning data, though, such "return" or "printf" or equivalent, else calls "emit" calls "return".

further searching, found bunch of times pseudocode form of "emit" appears in context of mapreduce. , in node.js. , in qt. that's it.

context: i'm (mostly) self-taught web programmer , system administrator. i'm sure question covered in compsci 101 (or 201?) didn't take course.

i've ever seen emit() used when building simple compiler in academia.

upon analyzing grammar of program, tokenize contents of , emit (push out) assembly instructions. (the compiler program written contained internal function called emit mirror theoretical/logical aspect of it.)

once grammar analysis complete, assembler take assembly instructions , generate binary code (aka machine code).

so, don't think there general cs definition emit; however, know used in pseudocode (and sometimes, actual code) writing compiler programs. , undergraduate level computer science education in us.