Move by Arguments

This small VSCode extension leverages a syntactic structure common to many languages---arguments---and lets you move and select text in terms of this structure.

Here, a set of arguments is defined as all text within a pair of brackets: [], () or {}, where each argument is separated by , or ;.

Using this extension, you can move the cursor by arguments or select arguments. You can also select the entire set of arguments plus the preceding identifier: a very common form for a function call.

Limitations

While this extension is quite usable, to keep things simple it leverages only the built-in APIs for interacting with brackets and syntax. This leads to some unfortunate drawbacks:

• motion can be slow and cursor can flash around: sending commands to move around brackets must move the cursor; you can't manipulate programmatic positions around brackets, so the user will sometimes "see" the computations this extension performs (albeit very rapidly)

• motions will stop at commas inside quotes: there is no built-in API to determine whether the current character falls inside a quote.

Ideally there would be a way to leverage the parsing VSCode already performs for syntax highlighting using a bulit-in API. However, this is not possible (see #580). The alternative, which would be to parse the entire source file redundantly within each extension, is not a sustainable approach for multiple, small extensions to take.