Initial commit

.config/lite-xl/plugins/editorconfig/parser.lua

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+-- Lua parser implementation of the .editorconfig spec as best understood.
+-- @copyright Jefferson Gonzalez <jgmdev@gmail.com>
+-- @license MIT
+
+local core = require "core"
+local config = require "core.config"
+
+local STANDALONE = false
+for i, argument in ipairs(ARGS) do
+  if argument == "test" and ARGS[i+1] == "editorconfig" then
+    STANDALONE = true
+  end
+end
+
+---Logger that will output using lite-xl logging functions or print to
+---terminal if the parser is running in standalone mode.
+---@param type "log" | "error"
+---@param format string
+---@param ... any
+local function log(type, format, ...)
+  if not STANDALONE then
+    core[type]("[EditorConfig]: " .. format, ...)
+  else
+    print("[" .. type:upper() .. "]: " .. string.format(format, ...))
+  end
+end
+
+---Represents an .editorconfig path rule/expression.
+---@class plugins.editorconfig.parser.rule
+---Path expression as found between square brackets.
+---@field expression string | table<integer,string>
+---The expression converted to a regex.
+---@field regex string | table<integer,string>
+---@field regex_compiled any? | table<integer,string>
+---@field negation boolean Indicates that the expression is a negation.
+---@field ranges table<integer,number> List of ranges found on the expression.
+
+---Represents a section of the .editorconfig with all its config options.
+---@class plugins.editorconfig.parser.section
+---@field rule plugins.editorconfig.parser.rule
+---@field equivalent_rules plugins.editorconfig.parser.rule[]
+---@field indent_style "tab" | "space"
+---@field indent_size integer
+---@field tab_width integer
+---@field end_of_line "lf" | "cr" | "crlf"
+---@field charset "latin1" | "utf-8" | "utf-8-bom" | "utf-16be" | "utf-16le"
+---@field trim_trailing_whitespace boolean
+---@field insert_final_newline boolean
+
+---EditorConfig parser class and filename config matching.
+---@class plugins.editorconfig.parser
+---@field config_path string
+---@field sections plugins.editorconfig.parser.section[]
+---@field root boolean
+local Parser = {}
+Parser.__index = Parser
+
+---Constructor
+---@param config_path string
+---@return plugins.editorconfig.parser
+function Parser.new(config_path)
+  local self = {}
+  setmetatable(self, Parser)
+  self.config_path = config_path
+  self.sections = {}
+  self.root = false
+  self:read()
+  return self
+end
+
+--- char to hex cache and automatic converter
+---@type table<string,string>
+local hex_value = {}
+setmetatable(hex_value, {
+  __index = function(t, k)
+    local v = rawget(t, k)
+    if v == nil then
+      v = string.format("%x", string.byte(k))
+      rawset(t, k, v)
+    end
+    return v
+  end
+})
+
+---Simplifies managing rules with other inner rules like {...} which can
+---contain escaped \\{ \\} and expressions that are easier handled after
+---converting the escaped special characters to \xXX counterparts.
+---@param value string
+---@return string escaped_values
+local function escapes_to_regex_hex(value)
+  local escaped_chars = {}
+  for char in value:ugmatch("\\(.)") do
+    table.insert(escaped_chars, char)
+  end
+  for _, char in ipairs(escaped_chars) do
+    value = value:ugsub("\\" .. char, "\\x" .. hex_value[char])
+  end
+  return value
+end
+
+---An .editorconfig path expression to regex conversion rule.
+---@class rule
+---@field rule string Lua pattern.
+---Callback conversion function.
+---@field conversion fun(match:string, section:plugins.editorconfig.parser.section):string
+
+---List of conversion rules applied to brace expressions.
+---@type rule[]
+local RULES_BRACES = {
+  { rule = "^%(",   conversion = function() return "\\(" end },
+  { rule = "^%)",   conversion = function() return "\\)" end },
+  { rule = "^%.",   conversion = function() return "\\." end },
+  { rule = "^\\%[", conversion = function() return "\\[" end },
+  { rule = "^\\%]", conversion = function() return "\\]" end },
+  { rule = "^\\!",  conversion = function() return "!" end },
+  { rule = "^\\;",  conversion = function() return ";" end },
+  { rule = "^\\#",  conversion = function() return "#" end },
+  { rule = "^\\,",  conversion = function() return "," end },
+  { rule = "^\\{",  conversion = function() return "{" end },
+  { rule = "^\\}",  conversion = function() return "}" end },
+  { rule = "^,",    conversion = function() return "|" end },
+  { rule = "^\\%*", conversion = function() return "\\*" end },
+  { rule = "^%*",   conversion = function() return "[^\\/]*" end },
+  { rule = "^%*%*", conversion = function() return ".*" end },
+  { rule = "^%?",   conversion = function() return "." end },
+  { rule = "^{}",   conversion = function() return "{}" end },
+  { rule = "^{[^,]+}", conversion = function(match) return match end },
+  { rule = "^%b{}",
+    conversion = function(match)
+      local out = match:ugsub("%(", "\\(")
+        :ugsub("%)", "\\)")
+        :ugsub("%.", "\\.")
+        :ugsub("\\%[", "[\\[]")
+        :ugsub("\\%]", "[\\]]")
+        :ugsub("^\\!", "!")
+        :ugsub("^\\;", ";")
+        :ugsub("^\\#", "#")
+        -- negation chars list
+        :ugsub("%[!(%a+)%]", "[^%1]")
+        :ugsub("\\\\", "[\\]")
+        -- escaped braces
+        :ugsub("\\{", "[{]")
+        :ugsub("\\}", "[}]")
+        -- non escaped braces
+        :ugsub("{([^%]])", "(%1")
+        :ugsub("}([^%]])", ")%1")
+        :ugsub("^{", "(")
+        :ugsub("}$", ")")
+        -- escaped globs
+        :ugsub("\\%*", "[\\*]")
+        :ugsub("\\%?", "[\\?]")
+        -- non escaped globs
+        :ugsub("%*%*", "[*][*]") -- prevent this glob from expanding to next sub
+        :ugsub("%*([^%]])", "[^\\/]*%1")
+        :ugsub("%[%*%]%[%*%]", ".*")
+        :ugsub("%?([^%]])", ".%1")
+        -- escaped comma
+        :ugsub("\\,", "[,]")
+        -- non escaped comma
+        :ugsub(",([^%]])", "|%1")
+      return out
+    end
+  },
+  { rule = "^%[[^/%]]*%]",
+    conversion = function(match)
+      local negation = match:umatch("^%[!")
+      local chars = match:umatch("^%[!?(.-)%]")
+      chars = chars:ugsub("^%-", "\\-"):ugsub("%-$", "\\-")
+      local out = ""
+      if negation then
+        out = "[^"..chars.."]"
+      else
+        out = "["..chars.."]"
+      end
+      return out
+    end
+  },
+}
+
+---List of conversion rules applied to .editorconfig path expressions.
+---@type rule[]
+local RULES = {
+  -- normalize escaped .editorconfig special chars or keep them escaped
+  { rule = "^\\x[a-fA-F][a-fA-F]", conversion = function(match) return match end },
+  { rule = "^\\%*", conversion = function() return "\\*" end },
+  { rule = "^\\%?", conversion = function() return "\\?" end },
+  { rule = "^\\{",  conversion = function() return "{" end },
+  { rule = "^\\}",  conversion = function() return "}" end },
+  { rule = "^\\%[",  conversion = function() return "\\[" end },
+  { rule = "^\\%]",  conversion = function() return "\\]" end },
+  { rule = "^\\!",  conversion = function() return "!" end },
+  { rule = "^\\;",  conversion = function() return ";" end },
+  { rule = "^\\#",  conversion = function() return "#" end },
+  -- escape special chars
+  { rule = "^%.",   conversion = function() return "\\." end },
+  { rule = "^%(",   conversion = function() return "\\(" end },
+  { rule = "^%)",   conversion = function() return "\\)" end },
+  { rule = "^%[[^/%]]*%]",
+    conversion = function(match)
+      local negation = match:umatch("^%[!")
+      local chars = match:umatch("^%[!?(.-)%]")
+      chars = chars:ugsub("^%-", "\\-"):ugsub("%-$", "\\-")
+      local out = ""
+      if negation then
+        out = "[^"..chars.."]"
+      else
+        out = "["..chars.."]"
+      end
+      return out
+    end
+  },
+  -- Is this negation rule valid?
+  { rule = "^!%w+",
+    conversion = function(match)
+      local chars = match:umatch("%w+")
+      return "[^"..chars.."]"
+    end
+  },
+  -- escape square brackets
+  { rule = "^%[",   conversion = function() return "\\[" end },
+  { rule = "^%]",   conversion = function() return "\\]" end },
+  -- match any characters
+  { rule = "^%*%*", conversion = function() return ".*" end },
+  -- match any characters excluding path separators, \ not needed but just in case
+  { rule = "^%*",   conversion = function() return "[^\\/]*" end },
+  -- match optional character, doesn't matters what or should only be a \w?
+  { rule = "^%?",   conversion = function() return "[^/]" end },
+  -- threat empty braces literally
+  { rule = "^{}",   conversion = function() return "{}" end },
+  -- match a number range
+  { rule = "^{%-?%d+%.%.%-?%d+}",
+    conversion = function(match, section)
+      local min, max = match:umatch("(-?%d+)%.%.(-?%d+)")
+      min = tonumber(min)
+      max = tonumber(max)
+      if min and max then
+        if not section.rule.ranges then section.rule.ranges = {} end
+        table.insert(section.rule.ranges, {
+          math.min(min, max),
+          math.max(min, max)
+        })
+      end
+      local minus = ""
+      if min < 0 or max < 0 then minus = "\\-?" end
+      return "(?<!0)("..minus.."[1-9]\\d*)"
+    end
+  },
+  -- threat single option braces literally
+  { rule = "^{[^,]+}", conversion = function(match) return match end },
+  -- match invalid range
+  { rule = "^{[^%.]+%.%.[^%.]+}", conversion = function(match) return match end },
+  -- match any of the strings separated by commas inside the curly braces
+  { rule = "^%b{}",
+    conversion = function(rule, section)
+      rule = rule:gsub("^{", ""):gsub("}$", "")
+      local pos, len, exp = 1, rule:ulen(), ""
+
+      while pos <= len do
+        local found = false
+        for _, r in ipairs(RULES_BRACES) do
+          local match = rule:umatch(r.rule, pos)
+          if match then
+            exp = exp .. r.conversion(match, section)
+            pos = pos + match:ulen()
+            found = true
+            break
+          end
+        end
+        if not found then
+          exp = exp .. rule:usub(pos, pos)
+          pos = pos + 1
+        end
+      end
+
+      return "(" .. exp .. ")"
+    end
+  }
+}
+
+---Adds the regex equivalent of a section path expression.
+---@param section plugins.editorconfig.parser.section | string
+---@return plugins.editorconfig.parser.section
+function Parser:rule_to_regex(section)
+  if type(section) == "string" then
+    section = {rule = {expression = section}}
+  end
+
+  local rule = section.rule.expression
+
+  -- match everything rule which is different from regular *
+  -- that doesn't matches path separators
+  if rule == "*" then
+    section.rule.regex = ".+"
+    section.rule.regex_compiled = regex.compile(".+")
+    return section
+  end
+
+  rule = escapes_to_regex_hex(section.rule.expression)
+
+  local pos, len, exp = 1, rule:ulen(), ""
+
+  -- if expression starts with ! it is treated entirely as a negation
+  local negation = rule:umatch("^%s*!")
+  if negation then
+    pos = pos + negation:ulen() + 1
+  end
+
+  -- apply all conversion rules by looping the path expression/rule
+  while pos <= len do
+    local found = false
+    for _, r in ipairs(RULES) do
+      local match = rule:umatch(r.rule, pos)
+      if match then
+        exp = exp .. r.conversion(match, section)
+        pos = pos + match:ulen()
+        found = true
+        break
+      end
+    end
+    if not found then
+      exp = exp .. rule:usub(pos, pos)
+      pos = pos + 1
+    end
+  end
+
+  -- force match up to the end
+  exp = exp .. "$"
+
+  -- allow expressions that start with * to match anything on start
+  if exp:match("^%[^\\/%]%*") then
+    exp = exp:gsub("^%[^\\/%]%*", ".*")
+  -- fixes two failing tests
+  elseif exp:match("^%[") then
+    exp = "^" .. exp
+  -- match only on root dir
+  elseif exp:match("^/") then
+    exp = exp:gsub("^/", "^")
+  end
+
+  -- store changes to the section rule
+  section.rule.regex, section.rule.negation = exp, negation
+  section.rule.regex_compiled = regex.compile(section.rule.regex)
+  if not section.rule.regex_compiled then
+    log(
+      "error",
+      "could not compile '[%s]' to regex '%s'",
+      rule, section.rule.regex
+    )
+  end
+
+  return section
+end
+
+---Parses the associated .editorconfig file and stores each section.
+function Parser:read()
+  local file = io.open(self.config_path, "r")
+
+  self.sections = {}
+
+  if not file then
+    log("log", "could not read %s", self.config_path)
+    return
+  end
+
+  ---@type plugins.editorconfig.parser.section
+  local section = {}
+
+  for line in file:lines() do
+    ---@cast line string
+
+    -- first we try to see if the line is a rule section
+    local rule = ""
+    rule = line:umatch("^%s*%[(.+)%]%s*$")
+    if rule then
+      if section.rule then
+        -- save previous section and crerate new one
+        table.insert(self.sections, section)
+        section = {}
+      end
+      section.rule = {
+        expression = rule
+      }
+      -- convert the expression to a regex directly on the section table
+      self:rule_to_regex(section)
+
+      local clone = rule
+      if clone:match("//+") or clone:match("/%*%*/") then
+        section.equivalent_rules = {}
+      end
+      while clone:match("//+") or clone:match("/%*%*/") do
+        ---@type plugins.editorconfig.parser.section[]
+        if clone:match("//+") then
+          clone = clone:ugsub("//+", "/", 1)
+          table.insert(section.equivalent_rules, self:rule_to_regex(clone).rule)
+        end
+        if clone:match("/%*%*/") then
+          clone = clone:ugsub("/%*%*/", "/", 1)
+          table.insert(section.equivalent_rules, self:rule_to_regex(clone).rule)
+        end
+      end
+    end
+
+    if not rule then
+      local name, value = line:umatch("^%s*(%w%S+)%s*=%s*([^\n\r]+)")
+      if name and value then
+        name = name:ulower()
+        -- do not lowercase property values that start with test_
+        if not name:match("^test_") then
+          value = value:ulower()
+        end
+        if value == "true" then
+          value = true
+        elseif value == "false" then
+          value = false
+        elseif math.tointeger and math.tointeger(value) then
+          value = math.tointeger(value)
+        elseif tonumber(value) then
+          value = tonumber(value)
+        end
+
+        if section.rule then
+          section[name] = value
+        elseif name == "root" and type(value) == "boolean" then
+          self.root = value
+        end
+      end
+    end
+  end
+
+  if section.rule then
+    table.insert(self.sections, section)
+  end
+end
+
+---Helper function that converts a regex offset results into a list
+---of strings, omitting the first result which is the complete match.
+---@param offsets table<integer,integer>
+---@param value string
+---@return table<integer, string>
+local function regex_result_to_table(offsets, value)
+  local result = {}
+  local offset_fix = 0
+  if not regex.find_offsets then
+    offset_fix = 1
+  end
+  for i=3, #offsets, 2 do
+    table.insert(result, value:sub(offsets[i], offsets[i+1]-offset_fix))
+  end
+  return result
+end
+
+---Get a matching config for the given filename or nil if nothing found.
+---@param file_name string
+---@param defaults? boolean Set indent size to defaults when needed,
+---@return plugins.editorconfig.parser.section?
+function Parser:getConfig(file_name, defaults)
+  if PLATFORM == "Windows" then
+    file_name = file_name:gsub("\\", "/")
+  end
+
+  local regex_match = regex.match
+  if regex.find_offsets then
+    regex_match = regex.find_offsets
+  end
+
+  local properties = {}
+
+  local found = false
+  for _, section in ipairs(self.sections) do
+    if section.rule.regex_compiled then
+      local negation = section.rule.negation
+      -- default rule
+      local matched = {regex_match(section.rule.regex_compiled, file_name)}
+      -- try equivalent rules if available
+      if not matched[1] and section.equivalent_rules then
+        for _, esection in ipairs(section.equivalent_rules) do
+          matched = {regex_match(esection.regex_compiled, file_name)}
+          if matched[1] then
+            break
+          end
+        end
+      end
+      if (matched[1] and not negation) or (not matched[1] and negation) then
+        local ranges_match = true
+        if section.rule.ranges then
+          local results = regex_result_to_table(matched, file_name)
+          if #results < #section.rule.ranges then
+            ranges_match = false
+          else
+            for i, range in ipairs(section.rule.ranges) do
+              local number = tonumber(results[i])
+              if not number then
+                ranges_match = false
+                break
+              end
+              if number < range[1] or number > range[2] then
+                ranges_match = false
+                break
+              end
+            end
+          end
+        end
+        if ranges_match then
+          found = true
+          for name, value in pairs(section) do
+            if name ~= "rule" and name ~= "equivalent_rules" then
+              properties[name] = value
+            end
+          end
+        end
+      end
+    end
+  end
+
+  if found and defaults then
+    if properties.indent_style and properties.indent_style == "space" then
+      if properties.indent_size and not properties.tab_width then
+        properties.tab_width = 4
+      end
+    elseif properties.indent_style and properties.indent_style == "tab" then
+      if not properties.tab_width and not properties.indent_size then
+        properties.indent_size = "tab"
+      elseif properties.tab_width then
+        properties.indent_size = properties.tab_width
+      end
+    end
+  end
+
+  return found and properties or nil
+end
+
+---Get a matching config for the given filename or nil if nothing found.
+---@param file_name string
+---@return string
+function Parser:getConfigString(file_name)
+  local out = ""
+  local properties = self:getConfig(file_name, true)
+  if properties then
+    local config_sorted = {}
+    for name, value in pairs(properties) do
+      table.insert(config_sorted, {name = name, value = value})
+    end
+    table.sort(config_sorted, function(a, b)
+      return a.name < b.name
+    end)
+    for _, value in ipairs(config_sorted) do
+      out = out .. value.name .. "=" .. tostring(value.value) .. "\n"
+    end
+  end
+  return out
+end
+
+return Parser