Editing Copy-and-paste programming (section)

== Deliberate design choice ==
Copy-and-paste programming is occasionally accepted as a valid programming technique. This is most commonly seen in boilerplate, such as class declarations or importing standard libraries, or in using an existing code template (with empty contents or stub functions) as a framework to fill in.

Use of programming idioms and [[Design pattern (computer science)|design patterns]] are similar to copy-and-paste programming, as they also use formulaic code. In some cases, this can be expressed as a [[Snippet (programming)|snippet]], which can then be pasted in when such code is necessary, though it is often simply recalled from the programmer's mind. In other cases idioms cannot be reduced to a code template. In most cases, however, even if an idiom can be reduced to code, it will be either long enough that it is abstracted into a function or short enough that it can be keyed in directly.

The [[Subtext programming language]] is a research project aimed at "decriminalizing" cut and paste. Using this language, cut and paste is the primary interaction model, and hence not considered an anti-pattern.

=== Example ===

A simple example is a for loop, which might be expressed as <syntaxhighlight lang=C inline>for (int i=0; i!=n; ++i) {}</syntaxhighlight>.

Sample code using such a for-loop might be:

<syntaxhighlight lang=C>
void foo(int n) {
    for (int i=0; i!=n; ++i) {
       /* body */
    }
}
</syntaxhighlight>
The looping code could then have been generated by the following snippet (specifying types and variable names):

<syntaxhighlight lang=c>
    for ($type $loop_var = 0; $loop_var != $stop; ++$loop_var) {
        /* body */
    }
</syntaxhighlight>