[wip] fix luacheck issues

benchmark/ips.lua

@@ -179,7 +179,7 @@ local floor = math.floor
 -- @treturn Integer Cycles per 100ms.
 
 local function cycles_per_100ms(time_nsec, iters)
-  cycles = floor((NANOSECONDS_PER_100MS / time_nsec) * iters)
+  local cycles = floor((NANOSECONDS_PER_100MS / time_nsec) * iters)
   if cycles <= 0 then return 1 else return cycles end
 end
 
@@ -202,15 +202,15 @@ function IPS:run_warmup()
     local before = Timing.now()
     local target = Timing.add_second(before, self.warmup)
 
-    warmup_iter = 0
+    local warmup_iter = 0
 
     while Timing.now() < target do
       item:call_times(1)
       warmup_iter = warmup_iter + 1
     end
 
-    after = Timing.now()
-    warmup_time_ns = Timing.time_ns(before, after)
+    local after = Timing.now()
+    local warmup_time_ns = Timing.time_ns(before, after)
 
     self.timing[item] = cycles_per_100ms(warmup_time_ns, warmup_iter)
 
@@ -228,16 +228,6 @@ local sum = function(t)
   return total
 end
 
-local map = function(t, f)
-  local m = {}
-
-  for i, n in ipairs(t) do
-    m[i] = f(n)
-  end
-
-  return m
-end
-
 local function stats_samples(measurements_ns, cycles)
   local samples = tab_new(#measurements_ns, 0)
 
@@ -283,7 +273,6 @@ function IPS:run_benchmark()
       insert(measurements_ns, iter_ns)
     end
 
-    local final_time = after
     local measured_ns = sum(measurements_ns)
     local samples = stats_samples(measurements_ns, cycles)
     local rep = self.full_report:add_entry(item.label, measured_ns, iter, Stats:new(samples), cycles)
@@ -294,15 +283,15 @@ end
 
 function IPS:run()
   if self.warmup and self.warmup > 0 then
-    for i=1, self.iterations do
+    for _=1, self.iterations do
       self:notify('start_warming')
       self:run_warmup()
     end
   end
 
   self:notify('start_running')
 
-  for i=1, self.iterations do
+  for _=1, self.iterations do
     self:run_benchmark()
   end
 
@@ -317,7 +306,7 @@ end
 function Entry:call_times(n)
   local action = self.action
 
-  for i=1, n do
+  for _=1, n do
     action()
   end
 end
@@ -336,8 +325,7 @@ function Report:add_entry(label, nanoseconds, iters, stats, measurement_cycle)
   return entry
 end
 
-function Report:body(format)
-  local left = ("%s (±%4.1f%%) i/s"):format()
+function Report.body(_)
 end
 
 function ReportEntry:new(label, nanoseconds, iterations, stats, measurement_cycle)
@@ -365,8 +353,8 @@ function ReportEntry:runtime()
 end
 
 local function stat_mean(samples)
-  local sum = sum(samples)
-  return sum / #samples
+  local total = sum(samples)
+  return total / #samples
 end
 
 local function stat_variance(samples, m)