The Go Programming Language

12.9 A Word of Caution

There is a lot more to the reflection API than we have space to show, but the preceding examples give an idea of what is possible. Reflection is a powerful and expressive tool, but it should be used with care, for three reasons.

The first reason is that reflection-based code can be fragile. For every mistake that would cause a compiler to report a type error, there is a corresponding way to misuse reflection, but whereas the compiler reports the mistake at build time, a reflection error is reported during execution as a panic, possibly long after the program was written or even long after it has started running.

If the readList function (§12.6), for example, should read a string from the input while populating a variable ...