8.0 KiB
Neogen - Your Annotation Toolkit
Table Of Contents
Features
- Create annotations with one keybind
- Defaults for multiple languages and annotation conventions
- Extremely customizable and extensible
- Written in lua
Requirements
- Install nvim-treesitter
Installation
Use your favorite package manager to install Neogen, e.g:
use {
"danymat/neogen",
config = function()
require('neogen').setup {
enabled = true
}
end,
requires = "nvim-treesitter/nvim-treesitter"
}
Usage
I exposed a command :Neogen to generate the annotations.
You can bind it to your keybind of choice, like so:
vim.api.nvim_set_keymap("n", "<Leader>ng", ":Neogen<CR>", {})
It'll generate the annotations provided by neogen.
Configuration
require('neogen').setup {
enabled = true, -- required for Neogen to work
input_after_comment = true, -- (default: true) automatic jump (with insert mode) on inserted annotation
}
}
If you're not satisfied with the default configuration for a language, you can change the defaults like this:
require('neogen').setup {
enabled = true,
languages = {
lua = {
template = {
annotation_convention = "emmylua" -- for a full list of annotation_conventions, see supported-languages below,
... -- for more template configurations, see the language's configuration file in configurations/{lang}.lua
}
},
...
}
}
Supported Languages
There is a list of supported languages and fields, with their annotation style
| Language | Annotation conventions | Supported fields |
|---|---|---|
| lua | Emmylua ("emmylua") |
@param, @varargs, @return |
| python | Google docstrings ("google_docstrings") |
Args:, Attributes: |
Adding Languages
Configuration file
The configuration file for a language is in lua/configurations/{lang}.lua.
Note: Be aware that Neogen uses Treesitter to operate. You can install TSPlayground to check the AST.
Below is a commented sample of the configuration file for lua.
-- Search for these nodes
parent = { "function", "local_function", "local_variable_declaration", "field", "variable_declaration" },
-- Traverse down these nodes and extract the information as necessary
data = {
-- If function or local_function is found as a parent
["function|local_function"] = {
-- Get second child from the parent node
["2"] = {
-- This second child has to be of type "parameters", otherwise does nothing
match = "parameters",
-- Extractor function that returns a set of TSname = values with values being of type string[]
extract = function(node)
local regular_params = neogen.utilities.extractors:extract_children_text("identifier")(node)
local varargs = neogen.utilities.extractors:extract_children_text("spread")(node)
return {
parameters = regular_params,
vararg = varargs,
}
end,
},
},
},
-- Custom lua locator that escapes from comments (More on locators below)
-- Passing nil will use the default locator
locator = require("neogen.locators.lua"),
-- Use default granulator and generator (More on them below)
granulator = nil,
generator = nil,
-- Template to use with the generator. (More on this below)
template = {
-- Which annotation convention to use
annotation_convention = "emmylua",
emmylua = {
{ nil, "- " },
{ "parameters", "- @param %s any" },
{ "vararg", "- @vararg any" },
{ "return_statement", "- @return any" }
}
},
The Neogen code is then divided in 3 major concepts:
Locators
A locator tries to find (from the cursor node) one of the nodes from parents field specified in configuration.
This is the signature of the function:
function(node_info, nodes_to_match)
return node
end
- With
node_infobeing a table with 2 fields:
{
root = root_node -- <TSnode>
current = current_node -- <TSnode>
}
nodes_to_matchis the field fromparentsin language configuration.
Default: The default locator (in lua/locators/default.lua) just go back to the parent node of the current one and sees if it's one of the requested parents.
Granulators
Now that a parent node is found (with locators) from the cursor location, it's time to use this node to find all requested fields.
The function signature is this:
function(parent_node, node_data)
return result
end
parent_nodebeing the node returned from the locatorresultis a table containing a set oftype = valueswith values from typestring[], and type being a TS node name.node_databeing the fielddatafrom configuration file. For example, if thedatafield is this one:
data = {
-- If function or local_function is found as a parent
["function|local_function"] = {
-- Get second child from the parent node
["2"] = {
-- This second child has to be of type "parameters", otherwise does nothing
match = "parameters",
-- Extractor function that returns a set of TSname = values with values being of type string[]
extract = function(node)
local regular_params = neogen.utilities.extractors:extract_children_text("identifier")(node)
local varargs = neogen.utilities.extractors:extract_children_text("spread")(node)
return {
parameters = regular_params,
vararg = varargs,
}
end,
},
},
},
Notes:
- If you create your own granulator, you can add any kind of parameters in the
datafield from configuration file as long as the function signature is the same provided. - Utilities are provided. You can check out their documentation in
lua/utilities/.
Generators
A generator takes in the results from the granulator and tries to generate the template according to the language's configuration.
This is the function signature for a generator:
function(parent, data, template)
return start_row, start_col, generated_template
end
parentis the parent node found with the locatordatais the result from the granulatortemplatebeing thetemplatefield from the language configuration file.start_rowis the row in which we will appendgenerated_templatestart_colis the col in which thegenerated_templatewill startgenerated_templateis the output we will append on the specified locations.
