Vim Tips Wiki:Code guidelines

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In short

When you need to display a block of code in a tip, it is best to use <pre> ... </pre> tags around the block.

A simple alternative is to insert a space before each line in the block, but that method can give the problems discussed below.

If you want syntax coloring, you can use <source lang="vim"> ... </source> instead of <pre>.

We use both <pre> and <source> blocks, without any strong preferences either way. Use whichever suits your taste, but please remain consistent with the rest of a tip when editing an existing one.

For inline code (for example, :s/old/new/), type <code>:s/old/new/</code>. See Template:code for more information.

Examples and explanations

When you use <pre>Some Text</pre> or <source>:

• Some Text is not parsed for wiki code (it's as if you had used <nowiki>).
• Some Text is taken as preformatted (so whitespace, including line breaks, is preserved).
• Some Text is displayed in a fixed-width font.
• Special characters (like < for <) are processed normally (but are usually not required, e.g. getline("'<") can be typed literally).

Simply prefixing each line with a space gives the same result as using the <pre> tag, except that in a line prefixed with a space, normal wiki processing rules apply (for example, '' gives italics).

Here is some sample wikitext that might be in a tip:

<pre>
function MyFunction()
  let newline = ''
  if getline("'>") != getline("'<")
    let newline = "\n"
  endif
  " More stuff would go here.
endfunction
</pre>

This is how the above wikitext is displayed:

function MyFunction()
  let newline = ''
  if getline("'>") != getline("'<")
    let newline = "\n"
  endif
  " More stuff would go here.
endfunction

Now the same, with syntax highlighting:

<source lang="vim">
function MyFunction()
  let newline = ''
  if getline("'>") != getline("'<")
    let newline = "\n"
  endif
  " More stuff would go here.
endfunction
</source>

Displayed as:

function MyFunction()
  let newline = ''
  if getline("'>") != getline("'<")
    let newline = "\n"
  endif
  " More stuff would go here.
endfunction

Problems using space prefix

Here is some text, using <pre> before the text, and </pre> after:

The first line looks good.
Here are some {{double braces}} in the text.
myvar = ''     " this comment explains that '' is an empty string
:nnoremap <F3> :let @+='http://www.example.com/?item='.expand('<cword>')<CR>

Here is exactly the same text, using the insert space before each line technique:

The first line looks good.
Here are some Template:Double braces in the text.
myvar =      " this comment explains that  is an empty string
:nnoremap <F3> :let @+='http://www.example.com/?item='.expand('<cword>')<CR>

The insert space before each line technique has these disadvantages:

• Punctuation may be mistaken for wiki syntax, so the display may be incorrect.
• Under some circumstances, if you select text from the spaced code block, you will find that each line has a trailing space (which is irritating if you want to paste the code into an example, and which can break some scripts).
• On long code blocks, it is easier to insert <pre> before the block and </pre> after.