added support for global "call" option

2 files changed, 41 insertions, 7 deletions

diff --git a/README.md b/README.md
index 27e96b5..9fc5c82 100644
--- a/README.md
+++ b/README.md
@@ -397,6 +397,32 @@ false   arguments:
 }
 ```
 
+#### Function call
+
+In case of success, the argument checker can call a function if
+needed. Some users might find it more convenient than calling the argument
+checker inside the function of interest. Taking back the first example, one
+could use the `call` option and rewrite it as:
+```lua
+addfive = argcheck{
+   {name="x", type="number"},
+
+   call = function(x)
+            print(string.format('%f + 5 = %f', x, x+5))
+          end
+}
+
+> addfive(5)
+5.000000 + 5 = 10.000000
+
+> addfive()
+stdin:1: arguments:
+{
+   x = number  --
+}
+```
+
+
 #### Debug
 
 Adding `debug=true` as global option will simply dump the corresponding code
diff --git a/init.lua b/init.lua
index a9dad42..13c8aaa 100644
--- a/init.lua
+++ b/init.lua
@@ -201,6 +201,9 @@ local function argcheck(rules)
    -- upvalues
    table.insert(txt, 'local isoftype')
    table.insert(txt, 'local usage')
+   if rules.call then
+      table.insert(txt, 'local call')
+   end
    for ridx, rule in ipairs(rules) do
       if rule.default or rule.defaultf then
          table.insert(txt, string.format('local arg%dd', ridx))
@@ -226,14 +229,15 @@ local function argcheck(rules)
          table.insert(ret, string.format('arg%d', ridx))
       end
    end
+   ret = table.concat(ret, ', ')
    if rules.pack then
-      ret = table.concat(ret, ', ')
-      ret = (rules.quiet and 'true, ' or '') .. '{' .. ret .. '}'
-   elseif rules.quiet then
-      table.insert(ret, 1, 'true')
-      ret = table.concat(ret, ', ')
-   else
-      ret = table.concat(ret, ', ')
+      ret = '{' .. ret .. '}'
+   end
+   if rules.call then
+      ret = 'call(' .. ret .. ')'
+   end
+   if rules.quiet then
+      ret = 'true' .. (#ret > 0 and ', ' or '') .. ret
    end
 
    table.insert(txt, '  local narg = select("#", ...)')
@@ -286,6 +290,10 @@ local function argcheck(rules)
 
    debug.setupvalue(func, upvalue2idx(func, 'usage'), generateusage(rules))
 
+   if rules.call then
+      debug.setupvalue(func, upvalue2idx(func, 'call'), rules.call)
+   end
+
    return func
 end