Editing Incremental compiler (section)

===Imperative programming===
In [[imperative programming]] and [[software development]], incremental compilation takes only the ''changes'' of a known set of [[source file]]s and ''updates'' any corresponding output files (in the compiler's target language, often [[bytecode]]) that may already exist from previous compilations.
By effectively ''building upon'' previously compiled output files, an incremental compiler avoids the wasteful recompiling of entire source files, where most of the code remains unchanged. For most incremental compilers, compiling a program with small changes to its source code is usually near instantaneous.
It can be said that an incremental compiler reduces the [[Granularity#Computing|granularity]] of a language's traditional compiling units while maintaining the language's [[semantics]], such that the compiler can append and replace smaller parts.

Many [[programming tool]]s take advantage of incremental compilers to provide developers with a much more interactive programming environment. It is not unusual that an incremental compiler is invoked for ''every'' change of a source file, such that the developer is almost immediately informed about any [[compilation error]]s that would arise as a result of their changes to the code. This scheme, in contrast with traditional compilation, shortens a programmer's development cycle significantly, because they would no longer have to wait for a long compile process before being informed of errors.

One downside to this type of incremental compiler is that it cannot easily [[optimization (computer science)|optimize]] the code that it compiles, due to locality and the limited scope of what is changed. This is usually not a problem, because for optimization is usually only carried out on [[software release cycle|release]], an incremental compiler would be used throughout development, and a standard batch compiler would be used on release.