Merge pull request #3743 from AndrielChaoti/andriel_argparse

Add `boolean` function for argparse

docs/changelog.txt

@@ -70,6 +70,7 @@ Template for new versions:
 - `overlay`: overlay widgets can now declare a ``version`` attribute. changing the version of a widget will reset its settings to defaults. this is useful when changing the overlay layout and old saved positions will no longer be valid.
 
 ## Lua
+- ``argparse.boolean``: convert arguments to lua boolean values.
 
 ## Removed
 

docs/dev/Lua API.rst

@@ -3538,6 +3538,12 @@ parameters.
   ``tonumber(arg)``. If ``arg_name`` is specified, it is used to make error
   messages more useful.
 
+* ``argparse.boolean(arg, arg_name)``
+  Converts ``string.lower(arg)`` from "yes/no/on/off/true/false/etc..." to a lua
+  boolean. Throws if the value can't be converted, otherwise returns
+  ``true``/``false``. If ``arg_name`` is specified, it is used to make error
+  messages more useful.
+
 dumper
 ======
 

library/lua/argparse.lua

@@ -196,4 +196,16 @@ function coords(arg, arg_name, skip_validation)
     return pos
 end
 
+local toBool={["true"]=true,["yes"]=true,["y"]=true,["on"]=true,["1"]=true,
+              ["false"]=false,["no"]=false,["n"]=false,["off"]=false,["0"]=false}
+function boolean(arg, arg_name)
+    local arg_lower = string.lower(arg)
+    if toBool[arg_lower] == nil then
+        arg_error(arg_name,
+            'unknown value: "%s"; expected "true", "yes", "false", or "no"', arg)
+    end
+
+    return toBool[arg_lower]
+end
+
 return _ENV