1 files changed, 121 insertions, 0 deletions
diff --git a/aconf/path.lua b/aconf/path.lua
new file mode 100644
index 0000000..4e289f5
--- /dev/null
+++ b/aconf/path.lua
@@ -0,0 +1,121 @@
+--[[
+Copyright (c) 2012-2015 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+local M = {}
+
+local map = require('aconf.util').map
+
+M.up = {symbol='..'}
+M.wildcard = {symbol='*'}
+local special = {['..']=M.up, ['*']=M.wildcard}
+
+
+function M.is_absolute(path) return path:sub(1, 1) == '/' end
+
+
+function M.escape(comp)
+   if type(comp) == 'table' then
+      assert(comp.symbol)
+      return comp.symbol
+   end
+   if type(comp) == 'number' then return tostring(comp) end
+   local res = comp:gsub('([\\/])', '\\%1')
+   return (special[res] or tonumber(res)) and '\\'..res or res
+end
+
+
+function M.rawjoin(p1, p2, ...)
+   if not p2 then return p1 end
+   if not M.is_absolute(p2) then p2 = '/'..p2 end
+   return M.rawjoin((p1 == '/' and '' or p1)..p2, ...)
+end
+
+function M.join(parent, ...)
+   local args = map(function(c) return M.escape(c) end, {...})
+   if parent > '' then table.insert(args, 1, parent) end
+   return M.rawjoin(table.unpack(args))
+end
+
+
+function M.split(path)
+   local res = {}
+   local comp = ''
+   local escaped
+
+   local function merge(s)
+      if s > '' then
+	 table.insert(res, not escaped and (special[s] or tonumber(s)) or s)
+      end
+   end
+
+   while true do
+      local prefix, sep, suffix = path:match('([^\\/]*)([\\/])(.*)')
+      if not prefix then
+	 merge(comp..path)
+	 return res
+      end
+
+      comp = comp..prefix
+      if sep == '\\' then
+	 comp = comp..suffix:sub(1, 1)
+	 escaped = true
+	 path = suffix:sub(2, -1)
+      else
+	 merge(comp)
+	 comp = ''
+	 escaped = false
+	 path = suffix
+      end
+   end
+end
+
+
+function M.is_unique(path)
+   for _, comp in ipairs(M.split(path)) do
+      if comp == M.wildcard then return false end
+   end
+   return true
+end
+
+function M.is_subordinate(p1, p2)
+   p1 = M.split(p1)
+   for i, comp in ipairs(M.split(p2)) do
+      if p1[i] ~= comp then return false end
+   end
+   return true
+end
+
+
+function M.to_absolute(path, base)
+   if not M.is_absolute(path) then
+      path = base..(base ~= '/' and '/' or '')..path
+   end
+   local comps = M.split(path)
+   local i = 1
+   while i <= #comps do
+      if comps[i] == M.up then
+	 if i == 1 then error('Invalid path: '..path) end
+	 table.remove(comps, i - 1)
+	 table.remove(comps, i - 1)
+	 i = i - 1
+      else i = i + 1 end
+   end
+   return M.join('/', table.unpack(comps))
+end
+
+
+function M.parent(path)
+   local comps = M.split(path)
+   table.remove(comps)
+   return M.join('/', table.unpack(comps))
+end
+
+function M.name(path)
+   local comps = M.split(path)
+   return comps[#comps]
+end
+
+
+return M