diff --git a/bin/moon b/bin/moon
index 0818d23..8ce4982 100755
--- a/bin/moon
+++ b/bin/moon
@@ -15,6 +15,7 @@ local help = [=[Usage: %s [options] [script [args]]
 
     -h          Print this message
     -d          Disable stack trace rewriting
+    -c          Collect and print code coverage
     -v          Print version
 ]=]
 
@@ -78,6 +79,13 @@ end
 
 if not opts.d then
 	local err, trace
+	local cov
+
+	if opts.c then
+		local coverage = require "moonscript.cmd.coverage"
+		cov = coverage.CodeCoverage()
+		cov:start()
+	end
 
 	xpcall(run_chunk, function(_err)
 		err = _err
@@ -97,6 +105,10 @@ if not opts.d then
 				util.trim(trace)
 			}, "\n"))
 		end
+	else
+		if cov then
+			cov:stop()
+		end
 	end
 else
 	run_chunk()
diff --git a/moonscript/cmd/coverage.lua b/moonscript/cmd/coverage.lua
new file mode 100644
index 0000000..be4923d
--- /dev/null
+++ b/moonscript/cmd/coverage.lua
@@ -0,0 +1,138 @@
+local moon = require("moon")
+local log
+log = function(str)
+  if str == nil then
+    str = ""
+  end
+  return io.stderr:write(str .. "\n")
+end
+local create_counter
+create_counter = function()
+  return setmetatable({ }, {
+    __index = function(self, name)
+      do
+        local tbl = setmetatable({ }, {
+          __index = function(self)
+            return 0
+          end
+        })
+        self[name] = tbl
+        return tbl
+      end
+    end
+  })
+end
+local position_to_lines
+position_to_lines = function(file_content, positions)
+  local lines = { }
+  local current_pos = 0
+  local line_no = 1
+  for char in file_content:gmatch(".") do
+    do
+      local count = rawget(positions, current_pos)
+      if count then
+        lines[line_no] = count
+      end
+    end
+    if char == "\n" then
+      line_no = line_no + 1
+    end
+    current_pos = current_pos + 1
+  end
+  return lines
+end
+local format_file
+format_file = function(fname, positions)
+  local file = assert(io.open(fname))
+  local content = file:read("*a")
+  file:close()
+  local lines = position_to_lines(content, positions)
+  log("------| @" .. tostring(fname))
+  local line_no = 1
+  for line in (content .. "\n"):gmatch("(.-)\n") do
+    local foramtted_no = ("% 5d"):format(line_no)
+    local sym = lines[line_no] and "*" or " "
+    log(tostring(sym) .. tostring(foramtted_no) .. "| " .. tostring(line))
+    line_no = line_no + 1
+  end
+  return log()
+end
+local CodeCoverage
+do
+  local _base_0 = {
+    start = function(self)
+      self.line_counts = create_counter()
+      return debug.sethook((function()
+        local _base_1 = self
+        local _fn_0 = _base_1.process_line
+        return function(...)
+          return _fn_0(_base_1, ...)
+        end
+      end)(), "l")
+    end,
+    stop = function(self)
+      debug.sethook()
+      local line_table = require("moonscript.line_tables")
+      return self:format_results()
+    end,
+    process_line = function(self, _, line_no)
+      local debug_data = debug.getinfo(2, "S")
+      local source = debug_data.source
+      self.line_counts[source][line_no] = self.line_counts[source][line_no] + 1
+    end,
+    format_results = function(self)
+      local line_table = require("moonscript.line_tables")
+      local positions = create_counter()
+      for file, lines in pairs(self.line_counts) do
+        local _continue_0 = false
+        repeat
+          local file_table = line_table[file]
+          if not (file_table) then
+            _continue_0 = true
+            break
+          end
+          for line, count in pairs(lines) do
+            local _continue_1 = false
+            repeat
+              local position = file_table[line]
+              if not (position) then
+                _continue_1 = true
+                break
+              end
+              positions[file][position] = positions[file][position] + count
+              _continue_1 = true
+            until true
+            if not _continue_1 then
+              break
+            end
+          end
+          _continue_0 = true
+        until true
+        if not _continue_0 then
+          break
+        end
+      end
+      for file, ps in pairs(positions) do
+        format_file(file, ps)
+      end
+    end
+  }
+  _base_0.__index = _base_0
+  local _class_0 = setmetatable({
+    __init = function() end,
+    __base = _base_0,
+    __name = "CodeCoverage"
+  }, {
+    __index = _base_0,
+    __call = function(cls, ...)
+      local _self_0 = setmetatable({}, _base_0)
+      cls.__init(_self_0, ...)
+      return _self_0
+    end
+  })
+  _base_0.__class = _class_0
+  CodeCoverage = _class_0
+end
+return {
+  CodeCoverage = CodeCoverage
+}
diff --git a/moonscript/cmd/coverage.moon b/moonscript/cmd/coverage.moon
new file mode 100644
index 0000000..5066406
--- /dev/null
+++ b/moonscript/cmd/coverage.moon
@@ -0,0 +1,76 @@
+
+moon = require "moon"
+
+log = (str="") ->
+  io.stderr\write str .. "\n"
+
+create_counter = ->
+  setmetatable {}, __index: (name) =>
+    with tbl = setmetatable {}, __index: => 0
+      @[name] = tbl
+
+position_to_lines = (file_content, positions) ->
+  lines = {}
+  current_pos = 0
+  line_no = 1
+  for char in file_content\gmatch "."
+    if count = rawget positions, current_pos
+      lines[line_no] = count
+
+    if char == "\n"
+      line_no += 1
+
+    current_pos += 1
+
+  lines
+
+format_file = (fname, positions) ->
+  file = assert io.open fname
+  content = file\read "*a"
+  file\close!
+
+  lines = position_to_lines content, positions
+  log "------| @#{fname}"
+  line_no = 1
+  for line in (content .. "\n")\gmatch "(.-)\n"
+    foramtted_no = "% 5d"\format(line_no)
+    sym = lines[line_no] and "*" or " "
+    log "#{sym}#{foramtted_no}| #{line}"
+    line_no += 1
+
+  log!
+
+
+class CodeCoverage
+  start: =>
+    @line_counts = create_counter!
+    debug.sethook @\process_line, "l"
+
+  stop: =>
+    debug.sethook!
+    line_table = require "moonscript.line_tables"
+
+    @format_results!
+
+  process_line: (_, line_no) =>
+    debug_data = debug.getinfo 2, "S"
+    source = debug_data.source
+    @line_counts[source][line_no] += 1
+
+  format_results: =>
+    line_table = require "moonscript.line_tables"
+    positions = create_counter!
+
+    for file, lines in pairs @line_counts
+      file_table = line_table[file]
+      continue unless file_table
+
+      for line, count in pairs lines
+        position = file_table[line]
+        continue unless position
+        positions[file][position] += count
+
+    for file, ps in pairs positions
+      format_file file, ps
+
+{ :CodeCoverage }