Syntax Node-based

The following selection modes are based on the syntax node of the file, which are powered by Tree-sitter.

Token

Keybinding: t

Token as in parser terminology, which represents the basic atoms of a syntax node.

It is useful for example, to select the name of the current variable (or identifier to be more general).

Syntax Node

This is one of my favourite selection mode, as it enable structural editing.

There are two Syntax Node selection modes:

• Coarse: faster movement, lower accuracy
• Fine: higher accuracy, slower movement

Syntax Node

Keybinding: s

Movement	Meaning
Previous/Next	Previous/Next named sibling node
Up	Parent node
Down	First named child node
Current	Largest node
Jump	Jump to largest node

Largest Node

Using the following Javascript expression as example:

fox.bar();

There are several syntax nodes that start with f¹:

• fox (identifier)
• fox.bar (member expression)
• fox.bar() (call expression)

Suppose the cursor is below f, pressing s selects fox.bar(), because fox.bar() is the largest node that starts with f.

Named node

When creating a Tree sitter grammar file for a language, the author can choose to not give names to a certain kind of nodes.

For example, "," are usually unnamed ( anonymous) in most language grammars, thus it will be skipped when using the Previous/Next movement in Syntax Node.

See more at https://tree-sitter.github.io/tree-sitter/using-parsers#named-vs-anonymous-nodes.

Fine Syntax Node

Keybinding: S
Reason: Coarse is more commonly used than Fine, thus Fine is assigned a harder-to-press key.

Movement	Meaning
Previous/Next	Previous/Next sibling node
Up	Parent node
Down	First child
Current	Smallest node that matches the current selection
Jump	Jump to smallest node

Fine Syntax Node is useful when you start to expand the selection starting from the current token.

Suppose we have the following Javascript expression, and the current selection is hello, and we want to select hello.world().

hello.world().foo().bar().spam().wise();

If we press s, the whole expression will be selected¹, and we will need to press j several times to shrink the selection down to hello.world().

However, if we use S instead, the selection will remain as hello, and pressing k multiple times will get us to hello.world().

Footnotes

1. You can try it out at https://astexplorer.net/, using the @typescript-eslint/parser. ↩ ↩²