1 files changed, 34 insertions, 41 deletions
diff --git a/nerv/init.lua b/nerv/init.lua
index 4d7b687..da7df29 100644
--- a/nerv/init.lua
+++ b/nerv/init.lua
@@ -98,24 +98,27 @@ function nerv.class(tname, parenttname)
 end
 
 function table.val_to_str(v)
-  if "string" == type(v) then
-    v = string.gsub(v, "\n", "\\n")
-    if string.match(string.gsub(v,"[^'\"]",""), '^"+$') then
-      return "'" .. v .. "'"
+    if "string" == type(v) then
+        v = string.gsub(v, "\n", "\\n")
+        if string.match(string.gsub(v,"[^'\"]",""), '^"+$') then
+            return "'" .. v .. "'"
+        end
+        return '"' .. string.gsub(v,'"', '\\"') .. '"'
+    else
+        return "table" == type(v) and table.tostring(v) or
+                    (("number" == type(v) or
+                    "string" == type(v) or
+                    "boolean" == type(v)) and tostring(v)) or
+                    nil -- failed to serialize
     end
-    return '"' .. string.gsub(v,'"', '\\"') .. '"'
-  else
-    return "table" == type(v) and table.tostring(v) or
-      tostring(v)
-  end
 end
 
 function table.key_to_str (k)
-  if "string" == type(k) and string.match(k, "^[_%a][_%a%d]*$") then
-    return k
-  else
-    return "[" .. table.val_to_str(k) .. "]"
-  end
+    if "string" == type(k) and string.match(k, "^[_%a][_%a%d]*$") then
+        return k
+    else
+        return "[" .. table.val_to_str(k) .. "]"
+    end
 end
 
 --- Get the string representation of a table, which can be executed as a valid
@@ -124,18 +127,18 @@ end
 -- @return the string representation which will result in a Lua table entity
 -- when evaluated
 function table.tostring(tbl)
-  local result, done = {}, {}
-  for k, v in ipairs(tbl) do
-    table.insert(result, table.val_to_str(v))
-    done[k] = true
-  end
-  for k, v in pairs(tbl) do
-    if not done[k] then
-      table.insert(result,
-        table.key_to_str(k) .. "=" .. table.val_to_str(v))
+    local result, done = {}, {}
+    for k, v in ipairs(tbl) do
+        table.insert(result, table.val_to_str(v))
+        done[k] = true
     end
-  end
-  return "{" .. table.concat(result, ",") .. "}"
+    for k, v in pairs(tbl) do
+        if not done[k] then
+            table.insert(result,
+            table.key_to_str(k) .. "=" .. table.val_to_str(v))
+        end
+    end
+    return "{" .. table.concat(result, ",") .. "}"
 end
 
 --- Get the class by name.
@@ -332,27 +335,17 @@ function nerv.print_usage(options)
                     (opt_full and '--' .. opt_full) or "",
                     (opt_short and '-' .. opt_short) or "",
                     opt_type,
-                    v.default or "",
+                    (v.default ~= nil and tostring(v.default)) or "",
                     v.desc or "")
     end
     nerv.printf("\n")
 end
 
--- function nerv.copy_file(fname1, fname2)
---     local fin, fout, err
---     fin, err = io.open(fname1, "r")
---     if fin then
---         fout, err = io.open(fname2, "w")
---     end
---     if not (fin and fout) then
---         nerv.error("[copy] from %s to %s: %s", fname1, fname2, err)
---     end
---     while true do
---         local b = fin:read(1024)
---         if b == nil then break end
---         fout:write(b)
---     end
--- end
+function table.extend(tbl1, tbl2)
+    for _, v in ipairs(tbl2) do
+        table.insert(tbl1, v)
+    end
+end
 
 -- the following lines trigger the initialization of basic modules