Fixed up nomsupath behavior and refactored file stuff into its own file.

16 files changed, 414 insertions, 258 deletions

diff --git a/Makefile b/Makefile
index a65ca4e..fc11273 100644
--- a/Makefile
+++ b/Makefile
@@ -9,11 +9,12 @@ LUA_BIN= $(shell which $(LUA))
 PREFIX=/usr/local
 NOMSU_BIN_DIR= $(PREFIX)/bin
 NOMSU_LIB_DIR= $(PREFIX)/lib/nomsu
+NOMSU_SHARE_DIR= $(PREFIX)/share/nomsu
 
 # ========= You shouldn't need to mess with any of these variables below ================
 
-MOON_FILES= code_obj.moon error_handling.moon nomsu.moon nomsu_compiler.moon nomsu_tree.moon parser.moon
-LUA_FILES= code_obj.lua consolecolors.lua error_handling.lua nomsu.lua nomsu_compiler.lua \
+MOON_FILES= code_obj.moon error_handling.moon files.moon nomsu.moon nomsu_compiler.moon nomsu_tree.moon parser.moon
+LUA_FILES= code_obj.lua consolecolors.lua error_handling.lua files.lua nomsu.lua nomsu_compiler.lua \
 		   nomsu_tree.lua parser.lua utils.lua uuid.lua
 CORE_NOM_FILES= $(wildcard core/*.nom)
 CORE_LUA_FILES= $(patsubst %.nom,%.lua,$(CORE_NOM_FILES))
@@ -37,7 +38,7 @@ test: build optimize
 .PHONY: check_header
 check_header: $(PEG_FILE) nomsu.lua $(CORE_NOM_FILES) $(LIB_NOM_FILES)
 	@if [ -f nomsu_latest ]; then \
-		NOMSU_HEADER="#!$(LUA_BIN)\\npackage.path = [[$(NOMSU_LIB_DIR)/`$(GET_VERSION)`/?.lua;]]..package.path\\npackage.nomsupath = [[$(NOMSU_LIB_DIR)/`$(GET_VERSION)`]]"; \
+		NOMSU_HEADER="#!$(LUA_BIN)\\nlocal NOMSU_VERSION, NOMSU_LIB, NOMSU_SHARE = [[`$(GET_VERSION)`]], [[$(NOMSU_LIB_DIR)]], [[$(NOMSU_SHARE_DIR)]]"; \
 		if [ "`head -n 3 nomsu_latest 2>/dev/null`" != "`echo $$NOMSU_HEADER`" ]; then \
 			rm -f nomsu_latest; \
 		fi; \
@@ -45,7 +46,7 @@ check_header: $(PEG_FILE) nomsu.lua $(CORE_NOM_FILES) $(LIB_NOM_FILES)
 
 nomsu_latest: nomsu.lua
 	@rm -f nomsu_latest
-	@NOMSU_HEADER="#!$(LUA_BIN)\\npackage.path = [[$(NOMSU_LIB_DIR)/`$(GET_VERSION)`/?.lua;]]..package.path\\npackage.nomsupath = [[$(NOMSU_LIB_DIR)/`$(GET_VERSION)`]]"; \
+	@NOMSU_HEADER="#!$(LUA_BIN)\\nlocal NOMSU_VERSION, NOMSU_LIB, NOMSU_SHARE = [[`$(GET_VERSION)`]], [[$(NOMSU_LIB_DIR)]], [[$(NOMSU_SHARE_DIR)]]"; \
 	echo $$NOMSU_HEADER | cat - nomsu.lua > nomsu_latest
 	@chmod +x nomsu_latest
 	@mv -f nomsu_latest nomsu`$(GET_VERSION)`
@@ -64,14 +65,46 @@ clean:
 
 .PHONY: install
 install: all
-	mkdir -pv $(NOMSU_BIN_DIR) && cp -v nomsu nomsu`$(GET_VERSION)` $(NOMSU_BIN_DIR)
-	mkdir -pv $(NOMSU_LIB_DIR)/`$(GET_VERSION)` && cp -rv $(LUA_FILES) $(PEG_FILE) core lib $(NOMSU_LIB_DIR)/`$(GET_VERSION)`
+	@echo "Nomsu will be installed to:"
+	@echo "    $(NOMSU_BIN_DIR)"
+	@echo "    $(NOMSU_LIB_DIR)"
+	@echo "    $(NOMSU_SHARE_DIR)"
+	@read -p "is that okay? [Y/n] " ans; \
+	if [[ ! $$ans =~ ^[Nn] ]]; then \
+		mkdir -pv $(NOMSU_BIN_DIR) $(NOMSU_LIB_DIR)/`$(GET_VERSION)` $(NOMSU_SHARE_DIR)/`$(GET_VERSION)` \
+		&& cp -v nomsu nomsu`$(GET_VERSION)` $(NOMSU_BIN_DIR) \
+		&& cp -rv $(LUA_FILES) $(PEG_FILE) core lib tests $(NOMSU_SHARE_DIR)/`$(GET_VERSION)`; \
+	fi
 
 .PHONY: uninstall
 uninstall: all
-	@echo "Deleting..."
-	@rm -rvf $(NOMSU_LIB_DIR)/`$(GET_VERSION)` $(NOMSU_BIN_DIR)/nomsu`$(GET_VERSION)`
-	@if [ "`ls $(NOMSU_BIN_DIR)/nomsu*`" == "nomsu" ]; then rm -v $(NOMSU_BIN_DIR)/nomsu; fi
-	@if [ "`ls $(NOMSU_LIB_DIR) 2>/dev/null`" == "" ]; then rm -rvf $(NOMSU_LIB_DIR); fi
+	@echo "Nomsu will be uninstalled from:"
+	@echo "    $(NOMSU_BIN_DIR)"
+	@echo "    $(NOMSU_LIB_DIR)"
+	@echo "    $(NOMSU_SHARE_DIR)"
+	@read -p "is that okay? [Y/n] " ans; \
+	if [[ ! $$ans =~ ^[Nn] ]]; then \
+		echo "Deleting..."; \
+		rm -rvf $(NOMSU_LIB_DIR)/`$(GET_VERSION)` $(NOMSU_SHARE_DIR)/`$(GET_VERSION)` $(NOMSU_BIN_DIR)/nomsu`$(GET_VERSION)`; \
+		if [ "`ls $(NOMSU_BIN_DIR)/nomsu* 2> /dev/null`" == "nomsu" ]; then \
+			rm -vf $(NOMSU_BIN_DIR)/nomsu; \
+		else \
+			if [ "`ls $(NOMSU_BIN_DIR)/nomsu* 2> /dev/null`" != "" ]; then \
+				read -p "It looks like there are other versions of Nomsu installed. Is it okay to leave the 'nomsu' cross-version launcher in place? (recommended) [Y/n]" ans; \
+				if [[ $$ans =~ ^[Nn] ]]; then \
+					echo "Deleting..."; \
+					rm -vf $(NOMSU_BIN_DIR)/nomsu; \
+				fi; \
+			fi; \
+		fi; \
+		if [ "`ls $(NOMSU_LIB_DIR) 2>/dev/null`" == "" ]; then rm -rvf $(NOMSU_LIB_DIR);\
+		else \
+			echo "Retaining $(NOMSU_LIB_DIR), since there are other files there."; \
+		fi; \
+		if [ "`ls $(NOMSU_SHARE_DIR) 2>/dev/null`" == "" ]; then rm -rvf $(NOMSU_SHARE_DIR);\
+		else \
+			echo "Retaining $(NOMSU_SHARE_DIR), since there are other files there."; \
+		fi; \
+	fi
 
 # eof
diff --git a/error_handling.lua b/error_handling.lua
index 90c5991..b0e6dde 100644
--- a/error_handling.lua
+++ b/error_handling.lua
@@ -1,3 +1,4 @@
+local files = require("files")
 local debug_getinfo = debug.getinfo
 local ok, to_lua = pcall(function()
   return require('moonscript.base').to_lua
@@ -97,7 +98,7 @@ print_error = function(error_message, stack_offset)
           end
           local filename, start, stop = calling_fn.source:match('@([^[]*)%[([0-9]+):([0-9]+)]')
           assert(filename)
-          local file = FILE_CACHE[filename]:sub(tonumber(start), tonumber(stop))
+          local file = read_file(filename):sub(tonumber(start), tonumber(stop))
           local err_line = get_line(file, calling_fn.currentline):sub(1, -2)
           local offending_statement = colored.bright(colored.red(err_line:match("^[ ]*(.*)")))
           if calling_fn.name then
@@ -118,7 +119,7 @@ print_error = function(error_message, stack_offset)
         else
           local file
           ok, file = pcall(function()
-            return FILE_CACHE[calling_fn.short_src]
+            return read_file(calling_fn.short_src)
           end)
           if not ok then
             file = nil
diff --git a/error_handling.moon b/error_handling.moon
index c71e782..5341348 100644
--- a/error_handling.moon
+++ b/error_handling.moon
@@ -1,4 +1,5 @@
 -- This file contains the logic for making nicer error messages
+files = require "files"
 debug_getinfo = debug.getinfo
 export SOURCE_MAP
 
@@ -62,7 +63,7 @@ print_error = (error_message, stack_offset=3)->
             --calling_fn.short_src = calling_fn.source\match('"([^[]*)')
             filename,start,stop = calling_fn.source\match('@([^[]*)%[([0-9]+):([0-9]+)]')
             assert(filename)
-            file = FILE_CACHE[filename]\sub(tonumber(start),tonumber(stop))
+            file = read_file(filename)\sub(tonumber(start),tonumber(stop))
             err_line = get_line(file, calling_fn.currentline)\sub(1,-2)
             offending_statement = colored.bright(colored.red(err_line\match("^[ ]*(.*)")))
             -- TODO: get name properly
@@ -73,7 +74,7 @@ print_error = (error_message, stack_offset=3)->
             else "main chunk"
             line = colored.yellow("#{filename}:#{calling_fn.currentline} in #{name}\n        #{offending_statement}")
         else
-            ok, file = pcall ->FILE_CACHE[calling_fn.short_src]
+            ok, file = pcall ->read_file(calling_fn.short_src)
             if not ok then file = nil
             local line_num
             if name == nil
diff --git a/files.lua b/files.lua
new file mode 100644
index 0000000..77bdf6d
--- /dev/null
+++ b/files.lua
@@ -0,0 +1,125 @@
+local files = { }
+local _FILE_CACHE = { }
+files.spoof = function(filename, contents)
+  _FILE_CACHE[filename] = contents
+end
+files.read = function(filename)
+  do
+    local file_contents = _FILE_CACHE[filename]
+    if file_contents then
+      return file_contents
+    end
+  end
+  local file = io.open(filename)
+  if package.nomsupath and not file then
+    for nomsupath in package.nomsupath:gmatch("[^;]+") do
+      file = io.open(nomsupath .. "/" .. filename)
+      if file then
+        break
+      end
+    end
+  end
+  if not (file) then
+    return nil
+  end
+  local contents = file:read("*a")
+  file:close()
+  _FILE_CACHE[filename] = contents
+  return contents
+end
+local iterate_single
+iterate_single = function(item, prev)
+  if item == prev then
+    return nil
+  else
+    return item
+  end
+end
+local match, sub, rep, gsub, format, byte, find
+do
+  local _obj_0 = string
+  match, sub, rep, gsub, format, byte, match, find = _obj_0.match, _obj_0.sub, _obj_0.rep, _obj_0.gsub, _obj_0.format, _obj_0.byte, _obj_0.match, _obj_0.find
+end
+iterate_single = function(item, prev)
+  if item == prev then
+    return nil
+  else
+    return item
+  end
+end
+local ok, lfs = pcall(require, "lfs")
+if ok then
+  files.walk = function(path)
+    local browse
+    browse = function(filename)
+      local file_type = lfs.attributes(filename, 'mode')
+      if file_type == 'file' then
+        if match(filename, "%.nom$") or match(filename, "%.lua$") then
+          coroutine.yield(filename)
+          return true
+        end
+      elseif file_type == 'directory' then
+        for subfile in lfs.dir(filename) do
+          if not (subfile == "." or subfile == "..") then
+            browse(filename .. "/" .. subfile)
+          end
+        end
+        return true
+      elseif file_type == 'char device' then
+        coroutine.yield(filename)
+        return true
+      end
+      return false
+    end
+    return coroutine.wrap(function()
+      if not browse(path) and package.nomsupath then
+        for nomsupath in package.nomsupath:gmatch("[^;]+") do
+          if browse(nomsupath .. "/" .. path) then
+            break
+          end
+        end
+      end
+      return nil
+    end)
+  end
+else
+  local ret = os.execute('find . -maxdepth 0')
+  if not (ret == true or ret == 0) then
+    error("Could not find 'luafilesystem' module and couldn't run system command `find` (this might happen on Windows). Please install `luafilesystem` (which can be found at: http://keplerproject.github.io/luafilesystem/ or `luarocks install luafilesystem`)", 0)
+  end
+  files.walk = function(path)
+    if match(path, "%.nom$") or match(path, "%.lua$") or match(path, "^/dev/fd/[012]$") then
+      return iterate_single, path
+    end
+    path = gsub(path, "\\", "\\\\")
+    path = gsub(path, "`", "")
+    path = gsub(path, '"', '\\"')
+    path = gsub(path, "$", "")
+    return coroutine.wrap(function()
+      local f = io.popen('find -L "' .. path .. '" -not -path "*/\\.*" -type f -name "*.nom"')
+      local found = false
+      for line in f:lines() do
+        found = true
+        coroutine.yield(line)
+      end
+      if not found and package.nomsupath then
+        f:close()
+        for nomsupath in package.nomsupath:gmatch("[^;]+") do
+          f = io.popen('find -L "' .. package.nomsupath .. '/' .. path .. '" -not -path "*/\\.*" -type f -name "*.nom"')
+          for line in f:lines() do
+            found = true
+            coroutine.yield(line)
+          end
+          f:close()
+          if found then
+            break
+          end
+        end
+      end
+      if not (found) then
+        return error("Invalid file path: " .. tostring(path))
+      end
+    end)
+  end
+end
+return files
diff --git a/files.moon b/files.moon
new file mode 100644
index 0000000..3abae95
--- /dev/null
+++ b/files.moon
@@ -0,0 +1,86 @@
+-- Some file utilities for searching for files recursively and using package.nomsupath
+files = {}
+
+_FILE_CACHE = {}
+
+-- Create a fake file and put it in the cache
+files.spoof = (filename, contents)->
+    _FILE_CACHE[filename] = contents
+
+-- Read a file's contents (searching first locally, then in the nomsupath)
+files.read = (filename)->
+    if file_contents = _FILE_CACHE[filename]
+        return file_contents
+    file = io.open(filename)
+    if package.nomsupath and not file
+        for nomsupath in package.nomsupath\gmatch("[^;]+")
+            file = io.open(nomsupath.."/"..filename)
+            break if file
+    return nil unless file
+    contents = file\read("*a")
+    file\close!
+    _FILE_CACHE[filename] = contents
+    return contents
+
+iterate_single = (item, prev) -> if item == prev then nil else item
+
+-- `walk` returns an iterator over all files matching a path.
+{:match, :sub, :rep, :gsub, :format, :byte, :match, :find} = string
+iterate_single = (item, prev) -> if item == prev then nil else item
+ok, lfs = pcall(require, "lfs")
+if ok
+    files.walk = (path)->
+        -- Return 'true' if any files or directories are found, otherwise 'false'
+        browse = (filename)->
+            file_type = lfs.attributes(filename, 'mode')
+            if file_type == 'file'
+                if match(filename, "%.nom$") or match(filename, "%.lua$")
+                    coroutine.yield filename
+                    return true
+            elseif file_type == 'directory'
+                for subfile in lfs.dir(filename)
+                    unless subfile == "." or subfile == ".."
+                        browse(filename.."/"..subfile)
+                return true
+            elseif file_type == 'char device'
+                coroutine.yield(filename)
+                return true
+            return false
+        return coroutine.wrap ->
+            if not browse(path) and package.nomsupath
+                for nomsupath in package.nomsupath\gmatch("[^;]+")
+                    break if browse(nomsupath.."/"..path)
+            return nil
+else
+    ret = os.execute('find . -maxdepth 0')
+    unless ret == true or ret == 0
+        error "Could not find 'luafilesystem' module and couldn't run system command `find` (this might happen on Windows). Please install `luafilesystem` (which can be found at: http://keplerproject.github.io/luafilesystem/ or `luarocks install luafilesystem`)", 0
+
+    files.walk = (path)->
+        -- Sanitize path
+        if match(path, "%.nom$") or match(path, "%.lua$") or match(path, "^/dev/fd/[012]$")
+            return iterate_single, path
+        -- TODO: improve sanitization
+        path = gsub(path,"\\","\\\\")
+        path = gsub(path,"`","")
+        path = gsub(path,'"','\\"')
+        path = gsub(path,"$","")
+        return coroutine.wrap ->
+            f = io.popen('find -L "'..path..'" -not -path "*/\\.*" -type f -name "*.nom"')
+            found = false
+            for line in f\lines!
+                found = true
+                coroutine.yield(line)
+            if not found and package.nomsupath
+                f\close!
+                for nomsupath in package.nomsupath\gmatch("[^;]+")
+                    f = io.popen('find -L "'..package.nomsupath..'/'..path..'" -not -path "*/\\.*" -type f -name "*.nom"')
+                    for line in f\lines!
+                        found = true
+                        coroutine.yield(line)
+                    f\close!
+                    break if found
+            unless found
+                error("Invalid file path: "..tostring(path))
+
+return files
diff --git a/lib/os.nom b/lib/os.nom
index be65370..8a27168 100644
--- a/lib/os.nom
+++ b/lib/os.nom
@@ -1,5 +1,10 @@
 use "core"
 
+action [path of Nomsu file %filename]
+    lua> ".."
+        for f in files.walk(\%filename) do return f end
+    barf "Could not find file: \%filename"
+
 action [sh> %cmd]
     lua> ".."
         local result = io.popen(\%cmd)
@@ -8,11 +13,15 @@ action [sh> %cmd]
         return contents
 
 action [read file %filename]
-    lua> ".."
-        local file = io.open(\%filename)
-        local contents = file:read("*a")
-        file:close()
-        return contents
+    =lua "files.read(\%filename)"
+
+compile [for file %f in %path %body] to
+    Lua ".."
+        for \(%f as lua expr) in files.walk(\(%path as lua expr)) do
+            \(%body as lua statements)
+            \(compile as: === next %f ===)
+        end
+        \(compile as: === stop %f ===)
 
 action [write to file %filename %text, to file %filename write %text]
     lua> ".."
diff --git a/lib/version.nom b/lib/version.nom
new file mode 100644
index 0000000..3b90888
--- /dev/null
+++ b/lib/version.nom
@@ -0,0 +1 @@
+lua> "NOMSU_LIB_VERSION = 2"
diff --git a/nomsu b/nomsu
index da566d1..af9993d 120000..100755
--- a/nomsu
+++ b/nomsu
@@ -1 +1,20 @@
-nomsu_runner
\ No newline at end of file
+#!/bin/bash
+while getopts ':V:' flag; do
+  case "${flag}" in
+    V) VERSION="${OPTARG/./\.}\\b" ;;
+  esac
+done
+
+if [[ $VERSION ]]; then
+    candidates=$(ls $(dirname $BASH_SOURCE) | grep "^nomsu$VERSION[0-9.]*$")
+else
+    candidates=$(ls $(dirname $BASH_SOURCE) | grep "^nomsu[0-9.]\+$")
+fi
+
+if [[ $candidates ]]; then
+    eval $(dirname $BASH_SOURCE)/$(echo "$candidates" | sort -V | tail -n 1) $@
+else
+    echo "Failed to find a Nomsu version matching the regex: \"nomsu$VERSION\""
+    echo "The versions available are:"
+    ls $(dirname $BASH_SOURCE) | grep "^nomsu[0-9.]\+$" | sed 's/^/    * /'
+fi
diff --git a/nomsu.lua b/nomsu.lua
index 44ad759..cfa515a 100644
--- a/nomsu.lua
+++ b/nomsu.lua
@@ -1,3 +1,55 @@
+if NOMSU_VERSION and NOMSU_LIB and NOMSU_SHARE then
+  local ver_bits
+  do
+    local _accum_0 = { }
+    local _len_0 = 1
+    for ver_bit in NOMSU_VERSION:gmatch("[0-9]+") do
+      _accum_0[_len_0] = ver_bit
+      _len_0 = _len_0 + 1
+    end
+    ver_bits = _accum_0
+  end
+  local partial_vers
+  do
+    local _accum_0 = { }
+    local _len_0 = 1
+    for i = #ver_bits, 1, -1 do
+      _accum_0[_len_0] = table.concat(ver_bits, '.', 1, i)
+      _len_0 = _len_0 + 1
+    end
+    partial_vers = _accum_0
+  end
+  package.path = table.concat((function()
+    local _accum_0 = { }
+    local _len_0 = 1
+    for _index_0 = 1, #partial_vers do
+      local v = partial_vers[_index_0]
+      _accum_0[_len_0] = tostring(NOMSU_SHARE) .. "/" .. tostring(v) .. "/?.lua"
+      _len_0 = _len_0 + 1
+    end
+    return _accum_0
+  end)(), ";") .. ";" .. package.path
+  package.cpath = table.concat((function()
+    local _accum_0 = { }
+    local _len_0 = 1
+    for _index_0 = 1, #partial_vers do
+      local v = partial_vers[_index_0]
+      _accum_0[_len_0] = tostring(NOMSU_LIB) .. "/" .. tostring(v) .. "/?.so"
+      _len_0 = _len_0 + 1
+    end
+    return _accum_0
+  end)(), ";") .. ";" .. package.cpath
+  package.nomsupath = table.concat((function()
+    local _accum_0 = { }
+    local _len_0 = 1
+    for _index_0 = 1, #partial_vers do
+      local v = partial_vers[_index_0]
+      _accum_0[_len_0] = tostring(NOMSU_SHARE) .. "/" .. tostring(v)
+      _len_0 = _len_0 + 1
+    end
+    return _accum_0
+  end)(), ";")
+end
 local EXIT_SUCCESS, EXIT_FAILURE = 0, 1
 local usage = [=[Nomsu Compiler
 
@@ -61,6 +113,7 @@ if not args or args.help then
   print(usage)
   os.exit(EXIT_FAILURE)
 end
+local files = require("files")
 local nomsu = NomsuCompiler
 nomsu.arg = args.nomsu_args
 if args.version then
@@ -79,85 +132,6 @@ FILE_CACHE = setmetatable({ }, {
     return contents
   end
 })
-local match, sub, rep, gsub, format, byte, find
-do
-  local _obj_0 = string
-  match, sub, rep, gsub, format, byte, match, find = _obj_0.match, _obj_0.sub, _obj_0.rep, _obj_0.gsub, _obj_0.format, _obj_0.byte, _obj_0.match, _obj_0.find
-end
-local iterate_single
-iterate_single = function(item, prev)
-  if item == prev then
-    return nil
-  else
-    return item
-  end
-end
-local lfs
-ok, lfs = pcall(require, "lfs")
-if ok then
-  all_files = function(path)
-    local browse
-    browse = function(filename)
-      local file_type = lfs.attributes(filename, 'mode')
-      if file_type == 'file' then
-        if match(filename, "%.nom$") or match(filename, "%.lua$") then
-          coroutine.yield(filename)
-          return true
-        end
-      elseif file_type == 'directory' then
-        for subfile in lfs.dir(filename) do
-          if not (subfile == "." or subfile == "..") then
-            browse(filename .. "/" .. subfile)
-          end
-        end
-        return true
-      elseif file_type == 'char device' then
-        coroutine.yield(filename)
-        return true
-      end
-      return false
-    end
-    return coroutine.wrap(function()
-      if not browse(path) and package.nomsupath then
-        browse(package.nomsupath .. "/" .. path)
-      end
-      return nil
-    end)
-  end
-else
-  local ret = os.execute('find . -maxdepth 0')
-  if not (ret == true or ret == 0) then
-    error("Could not find 'luafilesystem' module and couldn't run system command `find` (this might happen on Windows). Please install `luafilesystem` (which can be found at: http://keplerproject.github.io/luafilesystem/ or `luarocks install luafilesystem`)", 0)
-  end
-  all_files = function(path)
-    if match(path, "%.nom$") or match(path, "%.lua$") or match(path, "^/dev/fd/[012]$") then
-      return iterate_single, path
-    end
-    path = gsub(path, "\\", "\\\\")
-    path = gsub(path, "`", "")
-    path = gsub(path, '"', '\\"')
-    path = gsub(path, "$", "")
-    return coroutine.wrap(function()
-      local f = io.popen('find -L "' .. path .. '" -not -path "*/\\.*" -type f -name "*.nom"')
-      local found = false
-      for line in f:lines() do
-        found = true
-        coroutine.yield(line)
-      end
-      if not found and package.nomsupath then
-        f:close()
-        f = io.popen('find -L "' .. package.nomsupath .. '/' .. path .. '" -not -path "*/\\.*" -type f -name "*.nom"')
-        for line in f:lines() do
-          coroutine.yield(line)
-        end
-      end
-      local success = f:close()
-      if not (success) then
-        return error("Invalid file path: " .. tostring(path))
-      end
-    end)
-  end
-end
 local run
 run = function()
   for i, input in ipairs(args.inputs) do
@@ -199,7 +173,7 @@ run = function()
   local _list_0 = args.inputs
   for _index_0 = 1, #_list_0 do
     local input = _list_0[_index_0]
-    for f in all_files(input) do
+    for f in files.walk(input) do
       input_files[#input_files + 1] = f
       to_run[f] = true
     end
@@ -245,7 +219,7 @@ run = function()
         print_file:flush()
       end
     elseif args.format then
-      local file = FILE_CACHE[filename]
+      local file = files.read(filename)
       if not file then
         error("File does not exist: " .. tostring(filename), 0)
       end
@@ -257,7 +231,7 @@ run = function()
       end
     elseif filename == STDIN then
       local file = io.input():read("*a")
-      FILE_CACHE.stdin = file
+      files.spoof('stdin', file)
       nomsu:run(file, Source('stdin', 1, #file))
     else
       nomsu:run_file(filename)
@@ -305,7 +279,7 @@ run = function()
       end
       buff = table.concat(buff)
       local pseudo_filename = "user input #" .. repl_line
-      FILE_CACHE[pseudo_filename] = buff
+      files.spoof(pseudo_filename, buff)
       local err_hand
       err_hand = function(error_message)
         return Errhand.print_error(error_message)
diff --git a/nomsu.moon b/nomsu.moon
index 14f8992..19e7b26 100755
--- a/nomsu.moon
+++ b/nomsu.moon
@@ -1,5 +1,12 @@
 #!/usr/bin/env moon
 -- This file contains the command-line Nomsu runner.
+if NOMSU_VERSION and NOMSU_LIB and NOMSU_SHARE
+    ver_bits = [ver_bit for ver_bit in NOMSU_VERSION\gmatch("[0-9]+")]
+    partial_vers = [table.concat(ver_bits,'.',1,i) for i=#ver_bits,1,-1]
+    package.path = table.concat(["#{NOMSU_SHARE}/#{v}/?.lua" for v in *partial_vers],";")..";"..package.path
+    package.cpath = table.concat(["#{NOMSU_LIB}/#{v}/?.so" for v in *partial_vers],";")..";"..package.cpath
+    package.nomsupath = table.concat(["#{NOMSU_SHARE}/#{v}" for v in *partial_vers],";")
+
 EXIT_SUCCESS, EXIT_FAILURE = 0, 1
 usage = [=[
 Nomsu Compiler
@@ -58,11 +65,12 @@ if not args or args.help
     print usage
     os.exit(EXIT_FAILURE)
 
+files = require "files"
 nomsu = NomsuCompiler
 nomsu.arg = args.nomsu_args
 
 if args.version
-    nomsu\run 'use "core"\nsay (Nomsu version)' 
+    nomsu\run 'use "core"\nsay (Nomsu version)'
     os.exit(EXIT_SUCCESS)
 
 export FILE_CACHE
@@ -77,61 +85,6 @@ FILE_CACHE = setmetatable {}, {
         return contents
 }
 
-export all_files
-{:match, :sub, :rep, :gsub, :format, :byte, :match, :find} = string
-iterate_single = (item, prev) -> if item == prev then nil else item
-ok, lfs = pcall(require, "lfs")
-if ok
-    all_files = (path)->
-        browse = (filename)->
-            file_type = lfs.attributes(filename, 'mode')
-            if file_type == 'file'
-                if match(filename, "%.nom$") or match(filename, "%.lua$")
-                    coroutine.yield filename
-                    return true
-            elseif file_type == 'directory'
-                for subfile in lfs.dir(filename)
-                    unless subfile == "." or subfile == ".."
-                        browse(filename.."/"..subfile)
-                return true
-            elseif file_type == 'char device'
-                coroutine.yield(filename)
-                return true
-            return false
-        return coroutine.wrap ->
-            if not browse(path) and package.nomsupath
-                browse(package.nomsupath.."/"..path)
-            return nil
-else
-    ret = os.execute('find . -maxdepth 0')
-    unless ret == true or ret == 0
-        error "Could not find 'luafilesystem' module and couldn't run system command `find` (this might happen on Windows). Please install `luafilesystem` (which can be found at: http://keplerproject.github.io/luafilesystem/ or `luarocks install luafilesystem`)", 0
-
-    all_files = (path)->
-        -- Sanitize path
-        if match(path, "%.nom$") or match(path, "%.lua$") or match(path, "^/dev/fd/[012]$")
-            return iterate_single, path
-        -- TODO: improve sanitization
-        path = gsub(path,"\\","\\\\")
-        path = gsub(path,"`","")
-        path = gsub(path,'"','\\"')
-        path = gsub(path,"$","")
-        return coroutine.wrap ->
-            f = io.popen('find -L "'..path..'" -not -path "*/\\.*" -type f -name "*.nom"')
-            found = false
-            for line in f\lines!
-                found = true
-                coroutine.yield(line)
-            if not found and package.nomsupath
-                f\close!
-                f = io.popen('find -L "'..package.nomsupath..'/'..path..'" -not -path "*/\\.*" -type f -name "*.nom"')
-                for line in f\lines!
-                    coroutine.yield(line)
-            success = f\close!
-            unless success
-                error("Invalid file path: "..tostring(path))
-
-
 run = ->
     for i,input in ipairs args.inputs
         if input == "-" then args.inputs[i] = STDIN
@@ -159,7 +112,7 @@ run = ->
     input_files = {}
     to_run = {}
     for input in *args.inputs
-        for f in all_files(input)
+        for f in files.walk(input)
             input_files[#input_files+1] = f
             to_run[f] = true
 
@@ -194,7 +147,7 @@ run = ->
                 print_file\flush!
         elseif args.format
             -- Auto-format
-            file = FILE_CACHE[filename]
+            file = files.read(filename)
             if not file
                 error("File does not exist: #{filename}", 0)
             tree = nomsu\parse(file, Source(filename,1,#file))
@@ -204,7 +157,7 @@ run = ->
                 print_file\flush!
         elseif filename == STDIN
             file = io.input!\read("*a")
-            FILE_CACHE.stdin = file
+            files.spoof('stdin', file)
             nomsu\run(file, Source('stdin',1,#file))
         else
             nomsu\run_file(filename)
@@ -248,7 +201,7 @@ run = ->
             
             buff = table.concat(buff)
             pseudo_filename = "user input #"..repl_line
-            FILE_CACHE[pseudo_filename] = buff
+            files.spoof(pseudo_filename, buff)
             err_hand = (error_message)->
                 Errhand.print_error error_message
             ok, ret = xpcall(nomsu.run, err_hand, nomsu, buff, Source(pseudo_filename, 1, #buff))
diff --git a/nomsu_compiler.lua b/nomsu_compiler.lua
index c94685a..42cdb17 100644
--- a/nomsu_compiler.lua
+++ b/nomsu_compiler.lua
@@ -2,6 +2,7 @@ local lpeg = require('lpeg')
 local re = require('re')
 lpeg.setmaxstack(10000)
 local utils = require('utils')
+local files = require('files')
 local repr, stringify, equivalent
 repr, stringify, equivalent = utils.repr, utils.stringify, utils.equivalent
 colors = require('consolecolors')
@@ -60,45 +61,6 @@ table.fork = function(t, values)
     __index = t
   })
 end
-FILE_CACHE = setmetatable({ }, {
-  __index = function(self, filename)
-    local file = io.open(filename)
-    if not (file) then
-      return nil
-    end
-    local contents = file:read("*a")
-    file:close()
-    self[filename] = contents
-    return contents
-  end
-})
-local iterate_single
-iterate_single = function(item, prev)
-  if item == prev then
-    return nil
-  else
-    return item
-  end
-end
-all_files = function(path)
-  if match(path, "%.nom$") or match(path, "%.lua$") or match(path, "^/dev/fd/[012]$") then
-    return iterate_single, path
-  end
-  path = gsub(path, "\\", "\\\\")
-  path = gsub(path, "`", "")
-  path = gsub(path, '"', '\\"')
-  path = gsub(path, "$", "")
-  return coroutine.wrap(function()
-    local f = io.popen('find -L "' .. path .. '" -not -path "*/\\.*" -type f -name "*.nom"')
-    for line in f:lines() do
-      coroutine.yield(line)
-    end
-    local success = f:close()
-    if not (success) then
-      return error("Invalid file path: " .. tostring(path))
-    end
-  end)
-end
 local line_counter = re.compile([[    lines <- {| line (%nl line)* |}
     line <- {} (!%nl .)*
 ]], {
@@ -229,7 +191,7 @@ local NomsuCompiler = setmetatable({ }, {
   end
 })
 do
-  NomsuCompiler.NOMSU_COMPILER_VERSION = 1
+  NomsuCompiler.NOMSU_COMPILER_VERSION = 2
   NomsuCompiler.NOMSU_SYNTAX_VERSION = Parser.version
   NomsuCompiler._ENV = NomsuCompiler
   NomsuCompiler.nomsu = NomsuCompiler
@@ -245,7 +207,7 @@ do
     utils = utils,
     lpeg = lpeg,
     re = re,
-    all_files = all_files,
+    files = files,
     next = next,
     unpack = unpack,
     setmetatable = setmetatable,
@@ -299,7 +261,7 @@ do
   NomsuCompiler.LOADED = { }
   NomsuCompiler.AST = AST
   NomsuCompiler.compile_error = function(self, tok, err_format_string, ...)
-    local file = FILE_CACHE[tok.source.filename]
+    local file = files.read(tok.source.filename)
     local line_no = pos_to_line(file, tok.source.start)
     local line_start = LINE_STARTS[file][line_no]
     local src = colored.dim(file:sub(line_start, tok.source.start - 1))
@@ -422,8 +384,8 @@ do
       source = nil
     end
     source = source or (to_run.source or Source(to_run, 1, #to_run))
-    if not rawget(FILE_CACHE, source.filename) then
-      FILE_CACHE[source.filename] = to_run
+    if not files.read(source.filename) then
+      files.spoof(source.filename, to_run)
     end
     local tree
     if AST.is_syntax_tree(to_run) then
@@ -465,7 +427,7 @@ do
       return self.LOADED[filename]
     end
     local ret = nil
-    for filename in all_files(filename) do
+    for filename in files.walk(filename) do
       local _continue_0 = false
       repeat
         do
@@ -493,14 +455,14 @@ do
         end
         insert(_running_files, filename)
         if match(filename, "%.lua$") then
-          local file = assert(FILE_CACHE[filename], "Could not find file: " .. tostring(filename))
+          local file = assert(files.read(filename), "Could not find file: " .. tostring(filename))
           ret = self:run_lua(file, Source(filename, 1, #file))
         elseif match(filename, "%.nom$") or match(filename, "^/dev/fd/[012]$") then
           local ran_lua
           if self.can_optimize(filename) then
             local lua_filename = gsub(filename, "%.nom$", ".lua")
             do
-              local file = FILE_CACHE[lua_filename]
+              local file = files.read(lua_filename)
               if file then
                 ret = self:run_lua(file, Source(lua_filename, 1, #file))
                 ran_lua = true
@@ -508,7 +470,7 @@ do
             end
           end
           if not (ran_lua) then
-            local file = file or FILE_CACHE[filename]
+            local file = file or files.read(filename)
             if not file then
               error("File does not exist: " .. tostring(filename), 0)
             end
@@ -551,7 +513,11 @@ do
       local map = { }
       local offset = 1
       source = source or lua.source
-      local nomsu_str = tostring(FILE_CACHE[source.filename]:sub(source.start, source.stop))
+      local file = files.read(source.filename)
+      if not file then
+        error("Failed to find file: " .. tostring(source.filename))
+      end
+      local nomsu_str = tostring(file:sub(source.start, source.stop))
       local lua_line = 1
       local nomsu_line = pos_to_line(nomsu_str, source.start)
       local fn
@@ -684,7 +650,7 @@ do
           local bit_lua = self:compile(bit)
           if not (bit_lua.is_value) then
             local src = '    ' .. gsub(tostring(self:tree_to_nomsu(bit)), '\n', '\n    ')
-            local line = tostring(bit.source.filename) .. ":" .. tostring(pos_to_line(FILE_CACHE[bit.source.filename], bit.source.start))
+            local line = tostring(bit.source.filename) .. ":" .. tostring(pos_to_line(files.read(bit.source.filename), bit.source.start))
             self:compile_error(bit, "Cannot use:\n%s\nas a string interpolation value, since it's not an expression.")
           end
           if #lua.bits > 0 then
diff --git a/nomsu_compiler.moon b/nomsu_compiler.moon
index 56ef86e..e16af76 100644
--- a/nomsu_compiler.moon
+++ b/nomsu_compiler.moon
@@ -13,6 +13,7 @@ lpeg = require 'lpeg'
 re = require 're'
 lpeg.setmaxstack 10000
 utils = require 'utils'
+files = require 'files'
 {:repr, :stringify, :equivalent} = utils
 export colors, colored
 colors = require 'consolecolors'
@@ -49,37 +50,6 @@ table.fork = (t, values)-> setmetatable(values or {}, {__index:t})
 -- Add a ((%x foo %y) where {x:"asdf", y:"fdsa"}) compile-time action for substitution
 -- Re-implement nomsu-to-lua comment translation?
 
-export FILE_CACHE
--- FILE_CACHE is a map from filename (string) -> string of file contents
-FILE_CACHE = setmetatable {}, {
-    __index: (filename)=>
-        file = io.open(filename)
-        return nil unless file
-        contents = file\read("*a")
-        file\close!
-        self[filename] = contents
-        return contents
-}
-
-export all_files
-iterate_single = (item, prev) -> if item == prev then nil else item
-all_files = (path)->
-    -- Sanitize path
-    if match(path, "%.nom$") or match(path, "%.lua$") or match(path, "^/dev/fd/[012]$")
-        return iterate_single, path
-    -- TODO: improve sanitization
-    path = gsub(path,"\\","\\\\")
-    path = gsub(path,"`","")
-    path = gsub(path,'"','\\"')
-    path = gsub(path,"$","")
-    return coroutine.wrap ->
-        f = io.popen('find -L "'..path..'" -not -path "*/\\.*" -type f -name "*.nom"')
-        for line in f\lines!
-            coroutine.yield(line)
-        success = f\close!
-        unless success
-            error("Invalid file path: "..tostring(path))
-
 line_counter = re.compile([[
     lines <- {| line (%nl line)* |}
     line <- {} (!%nl .)*
@@ -158,7 +128,7 @@ dict = (t)-> setmetatable(t, _dict_mt)
 MAX_LINE = 80 -- For beautification purposes, try not to make lines much longer than this value
 NomsuCompiler = setmetatable({}, {__index: (k)=> if _self = rawget(@, "self") then _self[k] else nil})
 with NomsuCompiler
-    .NOMSU_COMPILER_VERSION = 1
+    .NOMSU_COMPILER_VERSION = 2
     .NOMSU_SYNTAX_VERSION = Parser.version
     ._ENV = NomsuCompiler
     .nomsu = NomsuCompiler
@@ -167,7 +137,7 @@ with NomsuCompiler
 
     -- Discretionary/convenience stuff
     to_add = {
-        repr:repr, stringify:stringify, utils:utils, lpeg:lpeg, re:re, all_files:all_files,
+        repr:repr, stringify:stringify, utils:utils, lpeg:lpeg, re:re, files:files,
         -- Lua stuff:
         :next, :unpack, :setmetatable, :coroutine, :rawequal, :getmetatable, :pcall,
         :error, :package, :os, :require, :tonumber, :tostring, :string, :xpcall, :module,
@@ -187,7 +157,7 @@ with NomsuCompiler
     .AST = AST
 
     .compile_error = (tok, err_format_string, ...)=>
-        file = FILE_CACHE[tok.source.filename]
+        file = files.read(tok.source.filename)
         line_no = pos_to_line(file, tok.source.start)
         line_start = LINE_STARTS[file][line_no]
         src = colored.dim(file\sub(line_start, tok.source.start-1))
@@ -289,7 +259,7 @@ with NomsuCompiler
 
     .run = (to_run, source=nil)=>
         source or= to_run.source or Source(to_run, 1, #to_run)
-        if not rawget(FILE_CACHE,source.filename) then FILE_CACHE[source.filename] = to_run
+        if not files.read(source.filename) then files.spoof(source.filename, to_run)
         tree = if AST.is_syntax_tree(to_run) then to_run else @parse(to_run, source)
         if tree == nil -- Happens if pattern matches, but there are no captures, e.g. an empty string
             return nil
@@ -321,7 +291,7 @@ with NomsuCompiler
         if @LOADED[filename]
             return @LOADED[filename]
         ret = nil
-        for filename in all_files(filename)
+        for filename in files.walk(filename)
             if ret = @LOADED[filename]
                 continue
 
@@ -334,16 +304,16 @@ with NomsuCompiler
 
             insert _running_files, filename
             if match(filename, "%.lua$")
-                file = assert(FILE_CACHE[filename], "Could not find file: #{filename}")
+                file = assert(files.read(filename), "Could not find file: #{filename}")
                 ret = @run_lua file, Source(filename, 1, #file)
             elseif match(filename, "%.nom$") or match(filename, "^/dev/fd/[012]$")
                 ran_lua = if @.can_optimize(filename) -- Look for precompiled version
                     lua_filename = gsub(filename, "%.nom$", ".lua")
-                    if file = FILE_CACHE[lua_filename]
+                    if file = files.read(lua_filename)
                         ret = @run_lua file, Source(lua_filename, 1, #file)
                         true
                 unless ran_lua
-                    file = file or FILE_CACHE[filename]
+                    file = file or files.read(filename)
                     if not file
                         error("File does not exist: #{filename}", 0)
                     ret = @run file, Source(filename,1,#file)
@@ -368,7 +338,10 @@ with NomsuCompiler
             map = {}
             offset = 1
             source or= lua.source
-            nomsu_str = tostring(FILE_CACHE[source.filename]\sub(source.start, source.stop))
+            file = files.read(source.filename)
+            if not file
+                error "Failed to find file: #{source.filename}"
+            nomsu_str = tostring(file\sub(source.start, source.stop))
             lua_line = 1
             nomsu_line = pos_to_line(nomsu_str, source.start)
             fn = (s)->
@@ -444,7 +417,7 @@ with NomsuCompiler
                     bit_lua = @compile(bit)
                     unless bit_lua.is_value
                         src = '    '..gsub(tostring(@tree_to_nomsu(bit)), '\n','\n    ')
-                        line = "#{bit.source.filename}:#{pos_to_line(FILE_CACHE[bit.source.filename], bit.source.start)}"
+                        line = "#{bit.source.filename}:#{pos_to_line(files.read(bit.source.filename), bit.source.start)}"
                         @compile_error bit,
                             "Cannot use:\n%s\nas a string interpolation value, since it's not an expression."
                     if #lua.bits > 0 then lua\append ".."
diff --git a/parser.lua b/parser.lua
index c04e95c..ad81252 100644
--- a/parser.lua
+++ b/parser.lua
@@ -132,7 +132,15 @@ do
       Parser.version = tonumber(v)
     end
   })
-  local peg_file = io.open("nomsu.peg") or (package.nomsupath and io.open(package.nomsupath .. "/nomsu.peg"))
+  local peg_file = io.open("nomsu.peg")
+  if not peg_file and package.nomsupath then
+    for path in package.nomsupath:gmatch("[^;]+") do
+      peg_file = io.open(path .. "/nomsu.peg")
+      if peg_file then
+        break
+      end
+    end
+  end
   assert(peg_file, "could not find nomsu.peg file")
   local nomsu_peg = peg_tidier:match(peg_file:read('*a'))
   peg_file:close()
diff --git a/parser.moon b/parser.moon
index a61b3c1..6fe54e6 100644
--- a/parser.moon
+++ b/parser.moon
@@ -56,7 +56,7 @@ NOMSU_DEFS = with {}
             return #src+1
         err_pos = start_pos
         line_no = pos_to_line(src, err_pos)
-        --src = FILE_CACHE[userdata.source.filename]
+        --src = files.read(userdata.source.filename)
         line_starts = LINE_STARTS[src]
         prev_line = line_no == 1 and "" or src\sub(line_starts[line_no-1] or 1, line_starts[line_no]-2)
         err_line = src\sub(line_starts[line_no], (line_starts[line_no+1] or 0)-2)
@@ -100,7 +100,11 @@ NOMSU_PATTERN = do
     ident <- [a-zA-Z_][a-zA-Z0-9_]*
     comment <- "--" [^%nl]*
     ]], {set_version: (v) -> Parser.version = tonumber(v)}
-    peg_file = io.open("nomsu.peg") or (package.nomsupath and io.open(package.nomsupath.."/nomsu.peg"))
+    peg_file = io.open("nomsu.peg")
+    if not peg_file and package.nomsupath
+        for path in package.nomsupath\gmatch("[^;]+")
+            peg_file = io.open(path.."/nomsu.peg")
+            break if peg_file
     assert(peg_file, "could not find nomsu.peg file")
     nomsu_peg = peg_tidier\match(peg_file\read('*a'))
     peg_file\close!
diff --git a/tests/metaprogramming.nom b/tests/metaprogramming.nom
index e7e22c5..0150350 100644
--- a/tests/metaprogramming.nom
+++ b/tests/metaprogramming.nom
@@ -1,4 +1,4 @@
-#..
+#
     Tests for the stuff defined in core/metaprogramming.nom
 
 use "core"
diff --git a/tests/os.nom b/tests/os.nom
index f96009f..c67279e 100644
--- a/tests/os.nom
+++ b/tests/os.nom
@@ -7,4 +7,7 @@ use "lib/os.nom"
 %lines <-: lines in: read file "tests/os.nom"
 assume: %lines.2 = "    Tests for the stuff defined in lib/os.nom"
 
+for file %f in "core"
+    say "\%f"
+
 say "OS test passed."