Snippets vs. Abbreviations in Vim

Question

What advantages and/or disadvantages are there to using a "snippets" plugin, e.g. snipmate, ultisnips, for VIM as opposed to simply using the builtin "abbreviations" functionality?

Are there specific use-cases where declaring iabbr, cabbr, etc. lack some major features that the snippets plugins provide? I've been unsuccessful in finding a thorough comparison between these two "features" and their respective implementations.

As @peter-rincker pointed out in a comment:

It should be noted that abbreviations can execute code as well. Often via <c-r>= or via an expression abbreviation (<expr>). Example which expands @@ to the current file's path: :iabbrev @@ <c-r>=expand('%:p')<cr>

As an example for python, let's compare a snipmate snippet and an abbrev in Vim for inserting lines for class declaration.

Snipmate

# New Class
snippet cl 
  class ${1:ClassName}(${2:object}):
    """${3:docstring for $1}"""
    def __init__(self, ${4:arg}):
      ${5:super($1, self).__init__()}
      self.$4 = $4 
      ${6}

Vimscript

au FileType python :iabbr cl class ClassName(object):<CR><Tab>"""docstring for ClassName"""<CR>def __init__(self, arg):<CR><Tab>super(ClassName, self).__init__()<CR>self.arg = arg

Am I missing some fundamental functionality of "snippets" or am I correct in assuming they are overkill for the most part, when Vim's abbr and :help template templates are able to do all most of the stuff snippets do?

I assume it's easier to implement snippets, and they provide additional aesthetic/visual features. For instance, if I use abbr in Vim and other plugins for running/testing python code inside vim--e.g. syntastic, pytest, ropevim, pep8, etc--am I missing out on some key features that snippets provide?

Answer 1

Everything that can be done with snippets can be done with abbreviations and vice-versa. You can have (mirrored or not) placeholders with abbreviations, you can have context-sensitive snippets.

There are two important differences:

• Abbreviations are triggered when the abbreviation text has been typed, and a non word character (or esc) is hit. Snippets are triggered on demand, and shortcuts are possible (no need to type while + tab. w + tab may be enough).
• It's much more easier to define new snippets (or to maintain old ones) than to define abbreviations. With abbreviations, a lot of boiler plate code is required when we want to do neat things.

There are a few other differences. For instance, abbreviations are always triggered everywhere. And seeing for expanded into for(placeholder) {\n} within a comment or a string context is certainly not what the end-user expects. With snippets, this is not a problem any more: we can expect the end-user to know what's he's doing when he asks to expand a snippet. Still, we can propose context-aware snippets that expand throw into @throw {domain::exception} {explanation} within a comment, or into throw domain::exception({message}); elsewhere.

Answer 2

Snippets

Rough superset of Vim's native abbreviations. Here are the highlights:

• Only trigger on key press
• Uses placeholders which a user can jump between
• Exist only for insert mode
• Dynamic expansions

Abbreviations

Great for common typos and small snippets.

• Native to Vim so no need for plugins
• Typically expand on whitespace or <c-]>
• Some special rules on trigger text (See :h abbreviations)
• Can be used in command mode via :cabbrev (often used to create command aliases)
• No placeholders
• Dynamic expansions

Conclusion

For the most part snippets are more powerful and provide many features that other editors enjoy, but you can use both and many people do. Abbreviations enjoy the benefit of being native which can be useful for remote environments. Abbreviations also enjoy another clear advantage which is can be used in command mode.

Answer 3

Snippets are more powerful.

Depending on the implementation, snippets can let you change (or accept defaults for) multiple placeholders and can even execute code when the snippet is expanded.

For example with ultisnips, you can have it execute shell commands, vimscript but also Python code.

An (ultisnips) example:

snippet hdr "General file header" b
# file: `!v expand('%:t')`
# vim:fileencoding=utf-8:ft=`!v &filetype`
# ${1}
#
# Author: ${2:J. Doe} ${3:<[email protected]>}
# Created: `!v strftime("%F %T %z")`
# Last modified: `!v strftime("%F %T %z")`
endsnippet

This presents you with three placeholders to fill in (it gives default values for two of them), and sets the filename, filetype and current date and time.

After the word "snippet", the start line contains three items;

• the trigger string,
• a description and
• options for the snippet.

Personally I mostly use the b option where the snippet is expanded at the beginning of a line and the w option that expands the snippet if the trigger string starts at the beginning of a word.

Note that you have to type the trigger string and then input a key or key combination that actually triggers the expansion. So a snippet is not expanded unless you want it to.

Additionally, snippets can be specialized by filetype. Suppose you want to define four levels of headings, h1 .. h4. You can have the same name expand differently between e.g. an HTML, markdown, LaTeX or restructuredtext file.

Answer 4

snippets are like the built-in :abbreviate on steroids, usually with:

• parameter insertions: You can insert (type or select) text fragments in various places inside the snippet. An abbreviation just expands once.
• mirroring: Parameters may be repeated (maybe even in transformed fashion) elsewhere in the snippet, usually updated as you type.
• multiple stops inside: You can jump from one point to another within the snippet, sometimes even recursively expand snippets within one.

There are three things to evaluate in a snippet plugin: First, the features of the snippet engine itself, second, the quality and breadth of snippets provided by the author or others; third, how easy it is to add new snippets.