--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lua/luadyncall/src/path.lua	Thu Mar 19 22:26:28 2015 +0100
@@ -0,0 +1,38 @@
+-- functions to initialize and search through paths.
+-- path strings specify a set of directory patterns separated by ';'.
+-- the searchpath function 
+
+--- Initialize lua-style paths.
+-- Looks up environment variable envname and substitute all ';;' by syspath
+-- @param envname name of environment variable
+-- @param syspath default value if envname is not set and substitution for all ';;'.
+-- @return value from env variable or syspath. ';;' in env will be substituted by syspath.
+
+function pathinit(envname, syspath)
+  local envvar = os.getenv(envname)
+  local path
+  if envvar then 
+    path = envvar:gsub(";;",syspath)
+  else
+    path = syspath
+  end
+  return path
+end
+
+
+--- find object by searching through the path 
+-- @param openfun function(expanded)
+-- @return found, expanded 
+
+function pathfind(path,name,openfun)  
+  local replaced = path:gsub("?", name)
+  local found = nil
+  local fails = {}
+  for expanded in replaced:gmatch("([^;]+)") do
+    found = openfun(expanded)
+    if found then return found, expanded end
+    table.insert(fails, expanded)
+  end
+  return nil, fails
+end
+