define-abbrev is the low-level basic function for defining an
abbrev in an abbrev table.
When a major mode defines a system abbrev, it should call
define-abbrev and specify
t for the
property. Be aware that any saved non-“system” abbrevs are restored
at startup, i.e., before some major modes are loaded. Therefore, major
modes should not assume that their abbrev tables are empty when they
are first loaded.
This function defines an abbrev named name, in abbrev-table, to expand to expansion and call hook, with properties props (see Abbrev Properties). The return value is name. The
:systemproperty in props is treated specially here: if it has the value
force, then it will overwrite an existing definition even for a non-“system” abbrev of the same name.
name should be a string. The argument expansion is normally the desired expansion (a string), or
nilto undefine the abbrev. If it is anything but a string or
nil, then the abbreviation “expands” solely by running hook.
The argument hook is a function or
nil. If hook is non-
nil, then it is called with no arguments after the abbrev is replaced with expansion; point is located at the end of expansion when hook is called.
If hook is a non-
no-self-insertproperty is non-
nil, hook can explicitly control whether to insert the self-inserting input character that triggered the expansion. If hook returns non-
nilin this case, that inhibits insertion of the character. By contrast, if hook returns
abbrev-insert) also returns
nil, as if expansion had not really occurred.
define-abbrevsets the variable
t, if it actually changes the abbrev. This is so that some commands will offer to save the abbrevs. It does not do this for a system abbrev, since those aren't saved anyway.
If this variable is non-
nil, it means that the user plans to use global abbrevs only. This tells the commands that define mode-specific abbrevs to define global ones instead. This variable does not alter the behavior of the functions in this section; it is examined by their callers.