Got rid of :prepare()

spec/help_spec.lua

@@ -8,7 +8,7 @@ describe("tests related to help message generation", function()
          "",
          "Options: ",
          "   -h, --help            Show this help message and exit. "
-      }, "\r\n"), parser:prepare():get_help())
+      }, "\r\n"), parser:get_help())
    end)
 
    it("does not create extra help options when :prepare is called several times", function()
@@ -18,7 +18,7 @@ describe("tests related to help message generation", function()
          "",
          "Options: ",
          "   -h, --help            Show this help message and exit. "
-      }, "\r\n"), parser:prepare():prepare():get_help())
+      }, "\r\n"), parser:get_help())
    end)
 
    it("uses custom help option", function()
@@ -29,7 +29,7 @@ describe("tests related to help message generation", function()
          "",
          "Options: ",
          "   /?                    Show this help message and exit. "
-      }, "\r\n"), parser:prepare():get_help())
+      }, "\r\n"), parser:get_help())
    end)
 
    it("uses description and epilog", function()
@@ -46,7 +46,7 @@ describe("tests related to help message generation", function()
          "   -h, --help            Show this help message and exit. ",
          "",
          "An epilog. "
-      }, "\r\n"), parser:prepare():get_help())
+      }, "\r\n"), parser:get_help())
    end)
 
    it("creates correct help message for arguments", function()
@@ -72,7 +72,7 @@ describe("tests related to help message generation", function()
          "",
          "Options: ",
          "   -h, --help            Show this help message and exit. "
-      }, "\r\n"), parser:prepare():get_help())
+      }, "\r\n"), parser:get_help())
    end)
 
    it("creates correct help message for options", function()
@@ -91,7 +91,7 @@ describe("tests related to help message generation", function()
          "   --from <server>",
          "   --config <config>",
          "   -h, --help            Show this help message and exit. "
-      }, "\r\n"), parser:prepare():get_help())
+      }, "\r\n"), parser:get_help())
    end)
 
    it("adds margin for multiline descriptions", function()
@@ -112,7 +112,7 @@ Sets verbosity level.
          "                         -v: Report all warnings. ",
          "                         -vv: Report all debugging information. ",
          "   -h, --help            Show this help message and exit. "
-      }, "\r\n"), parser:prepare():get_help())
+      }, "\r\n"), parser:get_help())
    end)
 
    it("creates correct help message for commands", function()
@@ -131,7 +131,7 @@ Sets verbosity level.
          "",
          "Commands: ",
          "   run                   Run! "
-      }, "\r\n"), parser:prepare():get_help())
+      }, "\r\n"), parser:get_help())
    end)
 
    it("creates correct help message for subcommands", function()
@@ -140,15 +140,13 @@ Sets verbosity level.
       local run = parser:command "run"
       run:option "--where"
 
-      parser:prepare()
-
       assert.equal(table.concat({
          "Usage: foo run [--where <where>] [-h]",
          "",
          "Options: ",
          "   --where <where>",
          "   -h, --help            Show this help message and exit. ",
-      }, "\r\n"), run:prepare():get_help())
+      }, "\r\n"), run:get_help())
    end)
 
    it("uses message provided by user", function()
@@ -158,7 +156,7 @@ Sets verbosity level.
 
       assert.equal(
          [=[I don't like your format of help messages]=],
-         parser:prepare():get_help()
+         parser:get_help()
       )
    end)
 end)

spec/usage_spec.lua

@@ -4,7 +4,7 @@ describe("tests related to usage message generation", function()
    it("creates correct usage message for empty parser", function()
       local parser = Parser "foo"
          :add_help(false)
-      assert.equal(parser:prepare():get_usage(), "Usage: foo")
+      assert.equal(parser:get_usage(), "Usage: foo")
    end)
 
    it("creates correct usage message for arguments", function()
@@ -21,7 +21,7 @@ describe("tests related to usage message generation", function()
       assert.equal(table.concat({
          "Usage: foo <first> <second-and-third> <second-and-third>",
          "       [<maybe-fourth>] [<others>] ..."
-         }, "\r\n"), parser:prepare():get_usage()
+         }, "\r\n"), parser:get_usage()
       )
    end)
 
@@ -36,7 +36,7 @@ describe("tests related to usage message generation", function()
 
       assert.equal(
          [=[Usage: foo [-q] --from <server> [--config <config>]]=],
-         parser:prepare():get_usage()
+         parser:get_usage()
       )
    end)
 
@@ -55,7 +55,7 @@ describe("tests related to usage message generation", function()
 
       assert.equal(
          [=[Usage: foo [<input>] [<pair> <pair>] [<pair2>] [<pair2>]]=],
-         parser:prepare():get_usage()
+         parser:get_usage()
       )
    end)
 
@@ -70,7 +70,7 @@ describe("tests related to usage message generation", function()
 
       assert.equal(
          [=[Usage: foo [-f <from>] [-o [<output>]]]=],
-         parser:prepare():get_usage()
+         parser:get_usage()
       )
    end)
 
@@ -83,7 +83,7 @@ describe("tests related to usage message generation", function()
 
       assert.equal(
          [=[Usage: foo [-q] <command> ...]=],
-         parser:prepare():get_usage()
+         parser:get_usage()
       )
    end)
 
@@ -95,15 +95,13 @@ describe("tests related to usage message generation", function()
          :add_help(false)
       run:option "--where"
 
-      parser:prepare()
-
       assert.equal(
          [=[Usage: foo run [--where <where>]]=],
-         run:prepare():get_usage()
+         run:get_usage()
       )
    end)
 
-   it("usage messages for commands are correct after several :prepare() invocations", function()
+   it("usage messages for commands are correct after several invocations", function()
       local parser = Parser "foo"
          :add_help(false)
       parser:flag "-q" "--quiet"
@@ -111,12 +109,12 @@ describe("tests related to usage message generation", function()
          :add_help(false)
       run:option "--where"
 
-      parser:prepare()
+      parser:parse{"run"}
-      parser:prepare()
+      parser:parse{"run"}
 
       assert.equal(
          [=[Usage: foo run [--where <where>]]=],
-         run:prepare():get_usage()
+         run:get_usage()
       )
    end)
 
@@ -129,7 +127,7 @@ describe("tests related to usage message generation", function()
 
          assert.equal(
             [=[Usage: obvious]=],
-            parser:prepare():get_usage()
+            parser:get_usage()
          )
       end)
 
@@ -141,7 +139,7 @@ describe("tests related to usage message generation", function()
 
          assert.equal(
             [=[Usage: foo [-q | --quiet]]=],
-            parser:prepare():get_usage()
+            parser:get_usage()
          )
       end)
 
@@ -154,7 +152,7 @@ describe("tests related to usage message generation", function()
 
          assert.equal(
             [=[Usage: foo <input> [<input>]]=],
-            parser:prepare():get_usage()
+            parser:get_usage()
          )
       end)
    end)

src/argparse.lua

@@ -88,8 +88,6 @@ local typecheck = setmetatable({}, {
    end
 })
 
-local noop = false
-
 local function aliased_name(self, name)
    typecheck.string "name" (self, name)
 
@@ -129,16 +127,14 @@ local Parser = add_setters(class {
    _arguments = {},
    _options = {},
    _commands = {},
-   _require_command = true,
+   _require_command = true
-   _add_help = true
 }, {
    name = typecheck.string "name",
    description = typecheck.string "description",
    epilog = typecheck.string "epilog",
    require_command = typecheck.boolean "require_command",
    usage = typecheck.string "usage",
-   help = typecheck.string "help",
+   help = typecheck.string "help"
-   add_help = noop
 })
 
 local Command = add_setters(Parser:extends {
@@ -153,8 +149,7 @@ local Command = add_setters(Parser:extends {
    require_command = typecheck.boolean "require_command",
    action = typecheck["function"] "action",
    usage = typecheck.string "usage",
-   help = typecheck.string "help",
+   help = typecheck.string "help"
-   add_help = noop
 })
 
 local Argument = add_setters(class {
@@ -303,51 +298,69 @@ end
 
 function Parser:option(...)
    local option = Option:new(...)
-   table.insert(self._options, option)
+
+   if self._has_help then
+      table.insert(self._options, #self._options, option)
+   else
+      table.insert(self._options, option)
+   end
+
    return option
 end
 
 function Parser:flag(...)
-   local flag = Option:new():args(0)(...)
+   return self:option():args(0)(...)
-   table.insert(self._options, flag)
-   return flag
 end
 
 function Parser:command(...)
-   local command = Command:new(...)
+   local command = Command:new():add_help(true)(...)
+   command._parent = self
    table.insert(self._commands, command)
    return command
 end
 
-function Parser:prepare()
+function Parser:add_help(param)
-   self._fullname = self._fullname or self._name
+   if self._has_help then
-
+      table.remove(self._options)
-   if self._add_help and not self._help_option then
+      self._has_help = false
-      self._help_option = self:flag()
+   end
+   
+   if param then
+      local help = self:flag()
          :description "Show this help message and exit. "
          :action(function()
             io.stdout:write(self:get_help() .. "\r\n")
             os.exit(0)
          end)
-         (self._add_help)
+         (param)
 
-      if not self._help_option._name then
+      if not help._name then
-         self._help_option "-h" "--help"
+         help "-h" "--help"
       end
-   end
 
-   for _, command in ipairs(self._commands) do
+      self._has_help = true
-      command._fullname = self._fullname .. " " .. command._name
    end
 
    return self
 end
 
-function Parser:update_charset(charset)
+function Parser:_get_fullname()
+   local parent = self._parent
+   local buf = {self._name}
+
+   while parent do
+      table.insert(buf, 1, parent._name)
+      parent = parent._parent
+   end
+
+   return table.concat(buf, " ")
+end
+
+function Parser:_update_charset(charset)
    charset = charset or {}
 
    for _, command in ipairs(self._commands) do
-      command:update_charset(charset)
+      command:_update_charset(charset)
    end
 
    for _, option in ipairs(self._options) do
@@ -367,7 +380,7 @@ function Parser:get_usage()
       return self._usage
    end
 
-   local lines = {usage_welcome .. self._fullname}
+   local lines = {usage_welcome .. self:_get_fullname()}
 
    local function add(s)
       if #lines[#lines]+1+#s <= max_usage_width then
@@ -553,7 +566,12 @@ end
 
 function Parser:_parse(args, errhandler)
    args = args or arg
-   self._name = self._name or args[0]
+   local noname
+
+   if not self._name then
+      noname = true
+      self._name = args[0]
+   end
 
    local parser
    local charset
@@ -682,7 +700,7 @@ function Parser:_parse(args, errhandler)
    end
 
    local function switch(p)
-      parser = p:prepare()
+      parser = p
 
       for _, option in ipairs(parser._options) do
          table.insert(options, option)
@@ -817,7 +835,7 @@ function Parser:_parse(args, errhandler)
    end
 
    switch(self)
-   charset = parser:update_charset()
+   charset = parser:_update_charset()
    mainloop()
 
    if cur_option then
@@ -857,6 +875,10 @@ function Parser:_parse(args, errhandler)
       end
    end
 
+   if noname then
+      self._name = nil
+   end
+
    return result
 end
 
@@ -890,4 +912,6 @@ function Parser:pparse(args)
    end
 end
 
-return Parser
+return function(...)
+   return Parser():add_help(true)(...)
+end