Emacs has commands for moving over or operating on words. By convention, the keys for them are all Meta characters.
Notice how these keys form a series that parallels the character-based C-f, C-b, C-d, C-t and DEL. M-@ is cognate to C-@, which is an alias for C-SPC.
The commands M-f (
forward-word) and M-b
backward-word) move forward and backward over words. These
Meta characters are thus analogous to the corresponding control
characters, C-f and C-b, which move over single characters
in the text. The analogy extends to numeric arguments, which serve as
repeat counts. M-f with a negative argument moves backward, and
M-b with a negative argument moves forward. Forward motion
stops right after the last letter of the word, while backward motion
stops right before the first letter.
kill-word) kills the word after point. To be
precise, it kills everything from point to the place M-f would
move to. Thus, if point is in the middle of a word, M-d kills
just the part after point. If some punctuation comes between point and the
next word, it is killed along with the word. (If you wish to kill only the
next word but not the punctuation before it, simply do M-f to get
the end, and kill the word backwards with M-DEL.)
M-d takes arguments just like M-f.
backward-kill-word) kills the word before
point. It kills everything from point back to where M-b would
move to. If point is after the space in `FOO, BAR', then
`FOO, ' is killed. (If you wish to kill just `FOO', do
M-b M-d instead of M-DEL.)
transpose-words) exchanges the word before or
containing point with the following word. The delimiter characters between
the words do not move. For example, `FOO, BAR' transposes into
`BAR, FOO' rather than `BAR FOO,'. See section Transposing Text, for
more on transposition and on arguments to transposition commands.
To operate on the next n words with an operation which applies
between point and mark, you can either set the mark at point and then move
over the words, or you can use the command M-@ (
which does not move point, but sets the mark where M-f would move
to. M-@ accepts a numeric argument that says how many words to
scan for the place to put the mark. In Transient Mark mode, this command
activates the mark.
The word commands' understanding of syntax is completely controlled by the syntax table. Any character can, for example, be declared to be a word delimiter. See section The Syntax Table.