Skeletons are a shorthand extension to the Lisp language, where various
atoms directly perform either actions on the current buffer or rudimentary
flow control mechanisms. Skeletons are interpreted by the function
A skeleton is a list starting with an interactor, which is usually a
nil when not needed, but can also be a Lisp
expression for complex read functions or for returning some calculated value.
The rest of the list are any number of elements as described in the following
Insert string or character. Literal strings and characters are passed through
skeleton-transformation when that is non-
Insert a newline and align under current line, but not if this is the
last element of a skeleton and the newline would be inserted at end of
line, or this is the first element and the newline would be inserted
at beginning of line. Use newline character
?\n to prevent
"\n" as the first or last string element of a
skeleton to insert a newline unconditionally.
Interesting point. When wrapping skeletons around successive regions, they are
put at these places. Point is left at first
_ where nothing is
Interesting point with no inter-region interaction; overrides
interesting point set by
Indent line according to major mode. When following element is
there is an interregion that will be wrapped here, indent that interregion.
Logical and. If preceding element moved point, i.e., usually inserted something, do following element.
Logical xor. If preceding element didn’t move point, i.e., usually inserted nothing, do following element.
Add position to
Delete preceding number characters. Depends on value of
Evaluated, and the return value is again interpreted as a skeleton element.
A special variable that, when evaluated the first time, usually prompts for input according to the skeleton’s interactor. It is then set to the return value resulting from the interactor. Each subskeleton has its local copy of this variable.
Skeleton-local user variables.
Evaluate following Lisp expression for its side-effect, but prevent it from being interpreted as a skeleton element.
Subskeletons are inserted recursively, not once, but as often as the user
enters something at the subskeletons interactor. Thus there must be a
str in the subskeleton. They can also be used non-interactively, when
prompt is a lisp-expression that returns successive list-elements.
Ignored. Execution resumes here if the user quits during skeleton interpretation.
Help form during interaction with the user or
Initial input (a string or a cons with index) while reading the input.
A constant which is non-
nil when the
resume: section was entered
because the user quit.
Some modes also use other skeleton elements they themselves defined. For
example in shell script mode’s skeletons you will find
< which does a
rigid indentation backwards, or in CC mode’s skeletons you find the
}. These are defined by the
skeleton-further-elements which is a list of
variables bound while interpreting a skeleton.
define-skeleton defines a command for interpreting a
skeleton. The first argument is the command name, the second is a
documentation string, and the rest is an interactor and any number of skeleton
elements together forming a skeleton. This skeleton is assigned to a variable
of the same name as the command and can thus be overridden from your
~/.emacs file (see Init File in The GNU Emacs Manual).