syntastica-query-preprocessor

The tree-sitter query pre-processor used by syntastica.

See the project overview for more information.

Overview

syntastica-query-preprocessor is a pre-processor for tree-sitter queries which allows usage of ; inherits <lang> comments, conditional skipping of nodes with comments, usage of additional predicates like lua-match?, contains? and any-of?, Neovim's old injections syntax, and order reversing for priority flipping. The crate can be used to use queries designed for Neovim with the official tree-sitter rust bindings with minimal manual changes.

Usage

This crate exposes six public functions:

• process_highlights
• process_injections
• process_locals
• process_highlights_with_inherits
• process_injections_with_inherits
• process_locals_with_inherits

The first three are used for simple pre-processing of a single query source file which is passed in as a &str.

The last three assume a directory structure of queries/<lang_name>/<highlights|injections|locals>.scm (where queries is the directory pointed to by the base_dir parameter), and read the queries from the file system. This allows usage of ; inherits <lang_one>[,<lang_two>,...] comments inside the query files to include the contents of another language's query file at the location of the comment. The lang_name parameter specifies the directory name in which the entry query file is located.

All six functions take the two arguments strip_comment and nvim_like. The strip_comment argument specifies a comment string that will indicate nodes to be excluded from the output. This must include the leading ;, so passing an empty string has the effect of not excluding anything.

Setting nvim_like to true mainly does the following:

#[not-]lua-match?, #[not-]any-of? and #[not-]contains? predicates are replaced with a #match? or #not-match? predicate expressing the same constraint. Note that regular expressions cannot represent all Lua patterns, so the conversion from lua-match to match may fail and panic.

Additional behavior differs for the kind of queries:

• For highlight queries, the order of the queries is reversed. This is needed because Neovim prioritizes queries lower down in the file over earlier ones, whereas the official tree-sitter Rust bindings do the opposite.
• For injection queries, Neovim used to use @<lang_name>, @content, @language, and @combined captures. These will be replaced with the new (and official) syntax using #set! injection.language "<lang_name>", @injection.content, @injection.language, and #set! injection.combined respectively.
• For locals queries, Neovim uses @scope, @reference, and various @definition.<kind> captures. These will be replaced by the official @local.scope, @local.reference, and @local.definition captures.