Using Helix
- Registers
- Surround
- Selecting and manipulating text with textobjects
- Navigating using tree-sitter textobjects
- Moving the selection with syntax-aware motions
For a full interactive introduction to Helix, refer to the
tutor which
can be accessed via the command hx --tutor
or :tutor
.
π‘ Currently, not all functionality is fully documented, please refer to the key mappings list.
Registers
In Helix, registers are storage locations for text and other data, such as the
result of a search. Registers can be used to cut, copy, and paste text, similar
to the clipboard in other text editors. Usage is similar to Vim, with "
being
used to select a register.
User-defined registers
Helix allows you to create your own named registers for storing text, for example:
"ay
- Yank the current selection to registera
."op
- Paste the text in registero
after the selection.
If a register is selected before invoking a change or delete command, the selection will be stored in the register and the action will be carried out:
"hc
- Store the selection in registerh
and then change it (delete and enter insert mode)."md
- Store the selection in registerm
and delete it.
Default registers
Commands that use registers, like yank (y
), use a default register if none is specified.
These registers are used as defaults:
Register character | Contains |
---|---|
/ | Last search |
: | Last executed command |
" | Last yanked text |
@ | Last recorded macro |
Special registers
Some registers have special behavior when read from and written to.
Register character | When read | When written |
---|---|---|
_ | No values are returned | All values are discarded |
# | Selection indices (first selection is 1 , second is 2 , etc.) | This register is not writable |
. | Contents of the current selections | This register is not writable |
% | Name of the current file | This register is not writable |
* | Reads from the system clipboard | Joins and yanks to the system clipboard |
+ | Reads from the primary clipboard | Joins and yanks to the primary clipboard |
When yanking multiple selections to the clipboard registers, the selections are joined with newlines. Pasting from these registers will paste multiple selections if the clipboard was last yanked to by the Helix session. Otherwise the clipboard contents are pasted as one selection.
Surround
Helix includes built-in functionality similar to vim-surround. The keymappings have been inspired from vim-sandwich:
Key Sequence | Action |
---|---|
ms<char> (after selecting text) | Add surround characters to selection |
mr<char_to_replace><new_char> | Replace the closest surround characters |
md<char_to_delete> | Delete the closest surround characters |
You can use counts to act on outer pairs.
Surround can also act on multiple selections. For example, to change every occurrence of (use)
to [use]
:
%
to select the whole files
to split the selections on a search term- Input
use
and hit Enter mr([
to replace the parentheses with square brackets
Multiple characters are currently not supported, but planned for future release.
Selecting and manipulating text with textobjects
In Helix, textobjects are a way to select, manipulate and operate on a piece of text in a structured way. They allow you to refer to blocks of text based on their structure or purpose, such as a word, sentence, paragraph, or even a function or block of code.
ma
- Select around the object (va
in Vim,<alt-a>
in Kakoune)mi
- Select inside the object (vi
in Vim,<alt-i>
in Kakoune)
Key after mi or ma | Textobject selected |
---|---|
w | Word |
W | WORD |
p | Paragraph |
( , [ , ' , etc. | Specified surround pairs |
m | The closest surround pair |
f | Function |
t | Type (or Class) |
a | Argument/parameter |
c | Comment |
T | Test |
g | Change |
π‘
f
,t
, etc. need a tree-sitter grammar active for the current document and a special tree-sitter query file to work properly. Only some grammars currently have the query file implemented. Contributions are welcome!
Navigating using tree-sitter textobjects
Navigating between functions, classes, parameters, and other elements is
possible using tree-sitter and textobject queries. For
example to move to the next function use ]f
, to move to previous
type use [t
, and so on.
For the full reference see the unimpaired section of the key bind documentation.
π‘ This feature relies on tree-sitter textobjects and requires the corresponding query file to work properly.
Moving the selection with syntax-aware motions
Alt-p
, Alt-o
, Alt-i
, and Alt-n
(or Alt
and arrow keys) allow you to move the
selection according to its location in the syntax tree. For example, many languages have the
following syntax for function calls:
func(arg1, arg2, arg3);
A function call might be parsed by tree-sitter into a tree like the following.
(call
function: (identifier) ; func
arguments:
(arguments ; (arg1, arg2, arg3)
(identifier) ; arg1
(identifier) ; arg2
(identifier))) ; arg3
Use :tree-sitter-subtree
to view the syntax tree of the primary selection. In
a more intuitive tree format:
ββββββ
βcallβ
βββββββ΄βββββ΄ββββββ
β β
βββββββΌβββββ ββββββΌβββββ
βidentifierβ βargumentsβ
β "func" β ββββββ΄ββββ¬ββββββ΄ββββ
ββββββββββββ β β β
β β β
βββββββββββΌβ ββββββΌββββββ ββΌββββββββββ
βidentifierβ βidentifierβ βidentifierβ
β "arg1" β β "arg2" β β "arg3" β
ββββββββββββ ββββββββββββ ββββββββββββ
If you have a selection that wraps arg1
(see the tree above), and you use
Alt-n
, it will select the next sibling in the syntax tree: arg2
.
// before
func([arg1], arg2, arg3)
// after
func(arg1, [arg2], arg3);
Similarly, Alt-o
will expand the selection to the parent node, in this case, the
arguments node.
func[(arg1, arg2, arg3)];
There is also some nuanced behavior that prevents you from getting stuck on a
node with no sibling. When using Alt-p
with a selection on arg1
, the previous
child node will be selected. In the event that arg1
does not have a previous
sibling, the selection will move up the syntax tree and select the previous
element. As a result, using Alt-p
with a selection on arg1
will move the
selection to the "func" identifier
.