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< h2 id = "moving-the-selection-with-syntax-aware-motions" > < a class = "header" href = "#moving-the-selection-with-syntax-aware-motions" > Moving the selection with syntax-aware motions< / a > < / h2 >
< p > < code > Alt-p< / code > , < code > Alt-o< / code > , < code > Alt-i< / code > , and < code > Alt-n< / code > (or < code > Alt< / code > 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:< / p >
< pre > < code class = "language-js" > func(arg1, arg2, arg3);
< / code > < / pre >
< p > A function call might be parsed by tree-sitter into a tree like the following.< / p >
< pre > < code class = "language-tsq" > (call
function: (identifier) ; func
arguments:
(arguments ; (arg1, arg2, arg3)
(identifier) ; arg1
(identifier) ; arg2
(identifier))) ; arg3
< / code > < / pre >
< p > Use < code > :tree-sitter-subtree< / code > to view the syntax tree of the primary selection. In
a more intuitive tree format:< / p >
< pre > < code > ┌────┐
│call│
┌─────┴────┴─────┐
│ │
┌─────▼────┐ ┌────▼────┐
│identifier│ │arguments│
│ "func" │ ┌────┴───┬─────┴───┐
└──────────┘ │ │ │
│ │ │
┌─────────▼┐ ┌────▼─────┐ ┌▼─────────┐
│identifier│ │identifier│ │identifier│
│ "arg1" │ │ "arg2" │ │ "arg3" │
└──────────┘ └──────────┘ └──────────┘
< / code > < / pre >
< p > If you have a selection that wraps < code > arg1< / code > (see the tree above), and you use
< code > Alt-n< / code > , it will select the next sibling in the syntax tree: < code > arg2< / code > .< / p >
< pre > < code class = "language-js" > // before
func([arg1], arg2, arg3)
// after
func(arg1, [arg2], arg3);
< / code > < / pre >
< p > Similarly, < code > Alt-o< / code > will expand the selection to the parent node, in this case, the
arguments node.< / p >
< pre > < code class = "language-js" > func[(arg1, arg2, arg3)];
< / code > < / pre >
< p > There is also some nuanced behavior that prevents you from getting stuck on a
node with no sibling. When using < code > Alt-p< / code > with a selection on < code > arg1< / code > , the previous
child node will be selected. In the event that < code > arg1< / code > does not have a previous
sibling, the selection will move up the syntax tree and select the previous
element. As a result, using < code > Alt-p< / code > with a selection on < code > arg1< / code > will move the
selection to the "func" < code > identifier< / code > .< / p >
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