Thought on XDG convention

[azzamsa]

tree-sitter puts the config in ~/.tree-sitter/config.json. Would it be better if fit in better with the XDG conventions?

[dcreager]

I like this idea, and we can leave ~/.tree-sitter/config.json as a legacy fallback location.

@maxbrunsfeld Is the config file ever needed by the C library, or is it only used by the Rust CLI tool? If we need this from C, there is some code we could lift from libcork that both defines the XDG locations and implements a "look for a file in this list of paths" search. [docs] [code]

[dcreager]

(and if it's only needed from Rust there's the xdg crate)

[patrickt]

I’m +1 on this too, viz. how Emacs looks in .emacs.d and .config/emacs.

[maxbrunsfeld]

Yeah, I'd be open to this. The config file is specific to the CLI, so there's not much cost to changing it.

[alemuller]

$XDG_DATA_HOME/tree-sitter could be suggest as one of the defaults directories in "parser-directories"on config file.

[gwerbin]

+1 to these! To recap, the "XDG way" would be something like this (in Bash-like syntax):

Config file: ${XDG_CONFIG_HOME:-$HOME/.config}/tree-sitter/config.json, using ~/.tree-sitter/config.json if that doesn't exist.

Parsers: ${XDG_DATA_HOME:-$HOME/.local/share}/tree-sitter/parsers/* as the first default in the config file, above the other ones that are already listed.

[Julian]

+1, but it's also nice to have an explicit environment variable (e.g. TREE_SITTER_HOME) to decide where the directory goes (if such an envvar existed someone who wanted this behavior could have had it already without waiting for specific XDG support)

[gwerbin]

+1, but it's also nice to have an explicit environment variable (e.g. TREE_SITTER_HOME) to decide where the directory goes (if such an envvar existed someone who wanted this behavior could have had it already without waiting for specific XDG support)

Note that the idea of a single "HOME" directory is somewhat incompatible with the XDG base directory setup, because in the XDG system you have two directories: one in XDG_CONFIG_HOME and the other in XDG_DATA_HOME.

A long time ago I implemented a patch for the Ruby Bundler tool that had some complicated fallback logic for this kind of thing: rubygems/bundler#6024

I propose the following for Tree Sitter:

• If TREE_SITTER_HOME is set, look in $TREE_SITTER_HOME/config.json and $TREE_SITTER_HOME/parsers/*.
• If TREE_SITTER_HOME is not set, look for Tree Sitter config files in $XDG_CONFIG_HOME/tree-sitter/config.json and parsers in $XDG_DATA_HOME/tree-sitter/parsers/*.

So this will still be a breaking change, but you can choose to set TREE_SITTER_HOME if you don't want to move your stuff into the XDG locations.

Also, note that there is some debate on Mac and Windows as to whether the default XDG locations should be the same as on Linux or should use something more platform-specific. See https://stackoverflow.com/q/3373948/2954547 (Mac) and https://stackoverflow.com/q/43853548/2954547 (Windows).

[p13nty]

For anyone trying to move out .tree-sitter directory from $HOME:

It turns out tree-sitter cli supports $TREE_SITTER_DIR.

Here is my config:

export TREE_SITTER_DIR="${XDG_CONFIG_HOME}/tree-sitter"

[ahlinc]

@maxbrunsfeld this issue was successfully resolved by awesome @dcreager rework of CLI with extraction of config loading logic to a separate crate. So this issue can be closed.