03-MoreFirstPrograms.md

More First Programs

Let's write a few variations of our first program.

Entry point

The first statement in a Go source file must be package name. Executable commands must always use package main. -- https://go.dev/doc/code

A package main and a file using a different package name cannot live in the same directory.

• example: x/twopkgs

$ make
found packages main (main.go) and other (other.go) in /home/tir/code/miku/gows/x/twopkgs

This is why you see a projects with entry points separating commands into a subdirectory, like cmd (which itself can be traced to plan9).

Not required for one-off tools, e.g.:

• embedmd
• crfs
• ...

For a first tool, this minimalistic approach is quite nice.

Encoding

Go code is expected to be encoded in UTF-8.

Source code in Go is defined to be UTF-8 text; no other representation is allowed. [...] To summarize, strings can contain arbitrary bytes, but when constructed from string literals, those bytes are (almost always) UTF-8. -- https://go.dev/blog/strings