lite-xl/data/plugins/detectindent.lua

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local core = require "core"
local command = require "core.command"
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local common = require "core.common"
local config = require "core.config"
local DocView = require "core.docview"
local Doc = require "core.doc"
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local tokenizer = require "core.tokenizer"
local cache = setmetatable({}, { __mode = "k" })
local function add_to_stat(stat, val)
for i = 1, #stat do
if val == stat[i][1] then
stat[i][2] = stat[i][2] + 1
return
end
end
stat[#stat + 1] = {val, 1}
end
local function optimal_indent_from_stat(stat)
if #stat == 0 then return nil, 0 end
local bins = {}
for k = 1, #stat do
local indent = stat[k][1]
local score = 0
local mult_prev, lines_prev
for i = k, #stat do
if stat[i][1] % indent == 0 then
local mult = stat[i][1] / indent
if not mult_prev or (mult_prev + 1 == mult and lines_prev / stat[i][2] > 0.1) then
-- we add the number of lines to the score only if the previous
-- multiple of "indent" was populated with enough lines.
score = score + stat[i][2]
end
mult_prev, lines_prev = mult, stat[i][2]
end
end
bins[#bins + 1] = {indent, score}
end
table.sort(bins, function(a, b) return a[2] > b[2] end)
return bins[1][1], bins[1][2]
end
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-- return nil if it is a comment or blank line or the initial part of the
-- line otherwise.
-- we don't need to have the whole line to detect indentation.
local function get_first_line_part(tokens)
local i, n = 1, #tokens
while i + 1 <= n do
local ttype, ttext = tokens[i], tokens[i + 1]
if ttype ~= "comment" and ttext:gsub("%s+", "") ~= "" then
return ttext
end
i = i + 2
end
end
local function get_non_empty_lines(syntax, lines)
return coroutine.wrap(function()
local tokens, state
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local i = 0
for _, line in ipairs(lines) do
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tokens, state = tokenizer.tokenize(syntax, line, state)
local line_start = get_first_line_part(tokens)
if line_start then
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i = i + 1
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coroutine.yield(i, line_start)
end
end
end)
end
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local auto_detect_max_lines = 200
local function detect_indent_stat(doc)
local stat = {}
local tab_count = 0
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for i, text in get_non_empty_lines(doc.syntax, doc.lines) do
local str = text:match("^ %s+%S")
if str then add_to_stat(stat, #str - 1) end
local str = text:match("^\t+")
if str then tab_count = tab_count + 1 end
-- Stop parsing when files is very long. Not needed for euristic determination.
if i > auto_detect_max_lines then break end
end
table.sort(stat, function(a, b) return a[1] < b[1] end)
local indent, score = optimal_indent_from_stat(stat)
if tab_count > score then
return "hard", nil, tab_count
else
return "soft", indent or config.indent_size, score or 0
end
end
local doc_text_input = Doc.text_input
local adjust_threshold = 5
local function update_cache(doc)
local type, size, score = detect_indent_stat(doc)
cache[doc] = { type = type, size = size }
doc.indent_spaces = (type == "hard" and "tab" or size) .. (score < adjust_threshold and "*" or "")
if score < adjust_threshold and Doc.text_input == doc_text_input then
Doc.text_input = function(self, ...)
doc_text_input(self, ...)
update_cache(self)
end
elseif score >= adjust_threshold and Doc.text_input ~= doc_text_input then
Doc.text_input = doc_text_input
end
end
local new = Doc.new
function Doc:new(...)
new(self, ...)
update_cache(self)
end
local clean = Doc.clean
function Doc:clean(...)
clean(self, ...)
update_cache(self)
end
local function with_indent_override(doc, fn, ...)
local c = cache[doc]
if not c then
return fn(...)
end
local type, size = config.tab_type, config.indent_size
config.tab_type, config.indent_size = c.type, c.size or config.indent_size
local r1, r2, r3 = fn(...)
config.tab_type, config.indent_size = type, size
return r1, r2, r3
end
local perform = command.perform
function command.perform(...)
return with_indent_override(core.active_view.doc, perform, ...)
end
local draw = DocView.draw
function DocView:draw(...)
return with_indent_override(self.doc, draw, self, ...)
end