Return parallel arrays from inline_options.get_issues_and_affecting_options

This reduces memory usage, getting rid of many tiny 2-item arrays.

Author: mpeterv

src/luacheck/filter.lua

@@ -429,15 +429,15 @@ local function annotate_file_report_with_affecting_options(file_report, option_s
    end
 
    local events, per_line_opts = inline_options.validate_options(file_report.events, file_report.per_line_options, stds)
-   local issues_with_inline_opts = inline_options.get_issues_and_affecting_options(events, per_line_opts)
+   local issues, inline_option_arrays = inline_options.get_issues_and_affecting_options(events, per_line_opts)
 
    local res = {
       issues = {},
       options = {}
    }
 
-   for i, pair in ipairs(issues_with_inline_opts) do
-      local issue, inline_opts = pair[1], pair[2]
+   for i, issue in ipairs(issues) do
+      local inline_opts = inline_option_arrays[i]
       local normalized_opts = caching_opts_normalizer:normalize_options(option_stack, inline_opts)
       res.issues[i] = issue
       res.options[i] = normalized_opts

src/luacheck/inline_options.lua

@@ -373,14 +373,13 @@ end
 
 -- Takes an array of events and a map of per-line options as returned from
 -- `get_events()`, possibly with location information stripped from push/pop events.
--- Returns an array of pairs {issue, option_attay} that matches each
--- warning or error with an array of inline option tables that affect it.
+-- Returns two parallel arrays, one with issues, one with option table arrays for the issues.
 -- Some option arrays may share identity.
--- Returned array is sorted by warning location.
 function inline_options.get_issues_and_affecting_options(events, per_line_opts)
    local pushes = utils.Stack()
    local option_stack = utils.Stack()
-   local res = {}
+   local issues = {}
+   local option_arrays = {}
    local empty_option_array = {}
 
    for _, event in ipairs(events) do
@@ -406,7 +405,8 @@ function inline_options.get_issues_and_affecting_options(events, per_line_opts)
             option_array = utils.concat_arrays({option_array, line_options})
          end
 
-         table.insert(res, {event, option_array})
+         table.insert(issues, event)
+         table.insert(option_arrays, option_array)
       elseif event.options then
          option_stack:push(event.options)
       elseif event.push then
@@ -423,7 +423,7 @@ function inline_options.get_issues_and_affecting_options(events, per_line_opts)
       end
    end
 
-   return res
+   return issues, option_arrays
 end
 
 -- Extract only warnings and errors from an array of events.