lualoader: Refactor config line expressions

A couple of issues addressed:

1.) Modules with - in the name were not recognized as modules
2.) The module regex was repeated for each place a module name may appear
3.) The 'strip leading space' bits were repeated for each expression
4.) The trailing 'comment validation' stuff was repeated every expression

#4 still has some more work to be done. exec lines, for instance, don't
capture a 'value' -- there's only one capture pattern. This throws off the
'c' value that we match, so the trailing bits aren't *actually* being
validated. This isn't a new issue, though, so a future comit will address
this.

stand/lua/config.lua

@@ -54,6 +54,8 @@ local MSG_KERNLOADING = "Loading kernel..."
 local MSG_MODLOADING = "Loading configured modules..."
 local MSG_MODLOADFAIL = "Could not load one or more modules!"
 
+local MODULEEXPR = '([%w-_]+)'
+
 local function restoreEnv()
 	-- Examine changed environment variables
 	for k, v in pairs(env_changed) do
@@ -121,14 +123,19 @@ local function processEnvVar(value)
 	return value
 end
 
+-- str in this table is a regex pattern.  It will automatically be anchored to
+-- the beginning of a line and any preceding whitespace will be skipped.  The
+-- pattern should have no more than two captures patterns, which correspond to
+-- the two parameters (usually 'key' and 'value') that are passed to the
+-- process function.  All trailing characters will be validated.
 local pattern_table = {
 	{
-		str = "^%s*(#.*)",
+		str = "(#.*)",
 		process = function(_, _)  end,
 	},
 	--  module_load="value"
 	{
-		str = "^%s*([%w_]+)_load%s*=%s*\"([%w%s%p]-)\"%s*(.*)",
+		str = MODULEEXPR .. "_load%s*=%s*\"([%w%s%p]-)\"",
 		process = function(k, v)
 			if modules[k] == nil then
 				modules[k] = {}
@@ -138,49 +145,49 @@ local pattern_table = {
 	},
 	--  module_name="value"
 	{
-		str = "^%s*([%w_]+)_name%s*=%s*\"([%w%s%p]-)\"%s*(.*)",
+		str = MODULEEXPR .. "_name%s*=%s*\"([%w%s%p]-)\"",
 		process = function(k, v)
 			setKey(k, "name", v)
 		end,
 	},
 	--  module_type="value"
 	{
-		str = "^%s*([%w_]+)_type%s*=%s*\"([%w%s%p]-)\"%s*(.*)",
+		str = MODULEEXPR .. "_type%s*=%s*\"([%w%s%p]-)\"",
 		process = function(k, v)
 			setKey(k, "type", v)
 		end,
 	},
 	--  module_flags="value"
 	{
-		str = "^%s*([%w_]+)_flags%s*=%s*\"([%w%s%p]-)\"%s*(.*)",
+		str = MODULEEXPR .. "_flags%s*=%s*\"([%w%s%p]-)\"",
 		process = function(k, v)
 			setKey(k, "flags", v)
 		end,
 	},
 	--  module_before="value"
 	{
-		str = "^%s*([%w_]+)_before%s*=%s*\"([%w%s%p]-)\"%s*(.*)",
+		str = MODULEEXPR .. "_before%s*=%s*\"([%w%s%p]-)\"",
 		process = function(k, v)
 			setKey(k, "before", v)
 		end,
 	},
 	--  module_after="value"
 	{
-		str = "^%s*([%w_]+)_after%s*=%s*\"([%w%s%p]-)\"%s*(.*)",
+		str = MODULEEXPR .. "_after%s*=%s*\"([%w%s%p]-)\"",
 		process = function(k, v)
 			setKey(k, "after", v)
 		end,
 	},
 	--  module_error="value"
 	{
-		str = "^%s*([%w_]+)_error%s*=%s*\"([%w%s%p]-)\"%s*(.*)",
+		str = MODULEEXPR .. "_error%s*=%s*\"([%w%s%p]-)\"",
 		process = function(k, v)
 			setKey(k, "error", v)
 		end,
 	},
 	--  exec="command"
 	{
-		str = "^%s*exec%s*=%s*\"([%w%s%p]-)\"%s*(.*)",
+		str = "exec%s*=%s*\"([%w%s%p]-)\"",
 		process = function(k, _)
 			if cli_execute_unparsed(k) ~= 0 then
 				print(MSG_FAILEXEC:format(k))
@@ -189,7 +196,7 @@ local pattern_table = {
 	},
 	--  env_var="value"
 	{
-		str = "^%s*([%w%p]+)%s*=%s*\"([%w%s%p]-)\"%s*(.*)",
+		str = "([%w%p]+)%s*=%s*\"([%w%s%p]-)\"",
 		process = function(k, v)
 			if setEnv(k, processEnvVar(v)) ~= 0 then
 				print(MSG_FAILSETENV:format(k, v))
@@ -198,7 +205,7 @@ local pattern_table = {
 	},
 	--  env_var=num
 	{
-		str = "^%s*([%w%p]+)%s*=%s*(-?%d+)%s*(.*)",
+		str = "([%w%p]+)%s*=%s*(-?%d+)",
 		process = function(k, v)
 			if setEnv(k, processEnvVar(v)) ~= 0 then
 				print(MSG_FAILSETENV:format(k, tostring(v)))
@@ -390,7 +397,8 @@ function config.parse(text)
 			local found = false
 
 			for _, val in ipairs(pattern_table) do
-				local k, v, c = line:match(val.str)
+				local pattern = '^%s*' .. val.str .. '%s*(.*)';
+				local k, v, c = line:match(pattern)
 				if k ~= nil then
 					found = true