eliminate explicit use of string module

2 files changed, 13 insertions, 9 deletions

diff --git a/acf/persistence/backends/augeas.lua b/acf/persistence/backends/augeas.lua
index ec13531..4cf623a 100644
--- a/acf/persistence/backends/augeas.lua
+++ b/acf/persistence/backends/augeas.lua
@@ -13,7 +13,7 @@ local copy = util.copy
 local function aug_path(path) return pth.join('/files', unpack(path)) end
 
 local function strip_name(name)
-   return type(name) == 'string' and string.match(name, '^[^][/=)%s]+') or name
+   return type(name) == 'string' and name:match('^[^][/=)%s]+') or name
 end
 
 local function ipath(path, index) return path..'['..index..']' end
@@ -26,7 +26,11 @@ function backend:init() self.aug = require('augeas').init() end
 function backend:find(path, leaf)
    util.map(
       function(comp)
-	 assert(comp == strip_name(comp) and not string.match(comp, '^%.+$'))
+	 assert(
+	    comp == strip_name(comp) and (
+	       type(comp) == 'number' or not comp:match('^%.+$')
+	    )
+	 )
       end,
       path
    )
@@ -107,7 +111,7 @@ function backend:set(mods)
 	    local ord = order(pth.join('/', unpack(path)))
 
 	    for _, sibling in ipairs(self.aug:match(pth.parent(mpath)..'/*')) do
-	       if order(string.sub(strip_name(sibling), 7, -1)) > ord then
+	       if order(strip_name(sibling):sub(7, -1)) > ord then
 		  self.aug:insert(sibling, pth.name(mpath), true)
 		  break
 	       end
diff --git a/acf/persistence/backends/files.lua b/acf/persistence/backends/files.lua
index b14ed10..7d03e12 100644
--- a/acf/persistence/backends/files.lua
+++ b/acf/persistence/backends/files.lua
@@ -17,9 +17,9 @@ local function get_scope(top)
       return
    end
 
-   return stringy.startswith(top.scope, '/files/') and string.sub(
-      top.scope, 7, -1
-   ) or nil
+   return stringy.startswith(
+      top.scope, '/files/'
+   ) and top.scope:sub(7, -1) or nil
 end
 
 
@@ -47,9 +47,9 @@ function backend:get(path, top)
 	 assert(scope)
 	 scope = scope..'/'
 
-	 local slen = string.len(scope)
-	 assert(string.sub(target, 1, slen) == scope)
-	 return string.sub(target, slen + 1, -1)
+	 local slen = scope:len()
+	 assert(target:sub(1, slen) == scope)
+	 return target:sub(slen + 1, -1)
 
       elseif t == 'directory' then
 	 local res = {}