added fs cache, closes #9

bin/moonbuild.moon

@@ -1,43 +1,44 @@
 #!/usr/bin/env moon
 
-argparse=require 'argparse'
+argparse = require 'argparse'
 
 require 'moonscript'
 import loadfile from require 'moonscript.base'
 import truncate_traceback, rewrite_traceback from require 'moonscript.errors'
 import trim from require 'moonscript.util'
 
-util=require 'moonbuild.util'
+util = require 'moonbuild.util'
+import freezecache, invalidatecache from require 'moonbuild.fsutil'
 import exists, mtime, run, min, max, first, flatten, match, patsubst, sortedpairs from util
 
 import insert, concat from table
 
-parser=argparse 'moonbuild'
+parser = argparse 'moonbuild'
 parser\argument('targets', "Targets to run")\args '*'
 parser\flag '-a --noskip', "Always run targets"
 parser\flag '-l --list', "List available targets"
 parser\flag '-d --deps', "List targets and their dependancies"
-args=parser\parse!
+args = parser\parse!
 
 -- util functions
-loadwithscope= (file, scope) ->
-	fn, err=loadfile file
+loadwithscope = (file, scope) ->
+	fn, err = loadfile file
 	error err or "failed to load code" unless fn
-	dumped, err=string.dump fn
+	dumped, err = string.dump fn
 	error err or "failed to dump function" unless dumped
 	load dumped, file, 'b', scope
-pcall= (fn, ...) ->
-	rewrite=(err) ->
-		trace=debug.traceback '', 2
-		trunc=truncate_traceback trim trace
-		rewrite_traceback trunc, err
+pcall = (fn, ...) ->
+	rewrite = (err) ->
+		trace = debug.traceback '', 2
+		trunc = truncate_traceback trim trace
+		(rewrite_traceback trunc, err) or trace
 	xpcall fn, rewrite, ...
 
 -- command object
 -- represents a command that can be called
 class Command
 	new: (@cmd, ...) =>
-		@args={...}
+		@args = {...}
 
 	__unm: => @run error: true, print: true
 	__len: => @run error: true
@@ -49,11 +50,11 @@ class Command
 -- build object
 -- represents a target
 class BuildObject
-	all={}
-	skip={}
+	all = {}
+	skip = {}
 
 	@find: (name) =>
-		target=all[name]
+		target = all[name]
 		return target if target
 		for glob, tgt in pairs all
 			return tgt if match name, glob
@@ -63,16 +64,16 @@ class BuildObject
 		{target, {dep, @find dep for dep in *target.deps} for name, target in pairs all}
 
 	@build: (name, upper) =>
-		target=(@find name) or error "No such target: #{name}"
+		target = (@find name) or error "No such target: #{name}"
 		target\build name, upper
 
 	__tostring: =>
 		"Target #{@name} (#{concat @deps, ', '})"
 
 	new: (@name, @outs={}, @ins={}, @deps={}, @fn= =>) =>
-		@skip=false
+		@skip = false
 		error "Duplicate build name #{@name}" if all[@name]
-		all[@name]=@
+		all[@name] = @
 
 	build: (name, upper={}) =>
 		return if skip[name]
@@ -84,43 +85,45 @@ class BuildObject
 			@@build dep, upper for dep in *@deps
 		return unless @shouldbuild name
 
-		ins=@ins
-		outs=@outs
+		ins = @ins
+		outs = @outs
 		if @name!=name
-			ins=[patsubst name, @name, elem for elem in *@ins]
-			outs=[patsubst name, @name, elem for elem in *@outs]
+			ins = [patsubst name, @name, elem for elem in *@ins]
+			outs = [patsubst name, @name, elem for elem in *@outs]
 			print "Building #{@name} as #{name}"
 		else
 			print "Building #{name}"
-		ok, err=pcall ->
+		freezecache file for file in *outs
+		ok, err = pcall ->
 			@.fn
 				ins: ins
 				outs: outs
 				infile: ins[1]
 				outfile: outs[1]
 				name: name
+		invalidatecache file for file in *outs
 		error "Can't build #{@name}: lua error\n#{err}" unless ok
 		for f in *outs
 			error "Can't build #{@name}: output file #{f} not created" unless exists f
-		skip[name]=true
+		skip[name] = true
 
 	shouldbuild: (name) =>
 		return true if args.noskip
 		return true if #@ins==0 or #@outs==0
 
-		ins=if @name!=name
+		ins = if @name!=name
 			[patsubst name, @name, elem for elem in *@ins]
 		else
 			@ins
-		itimes=[mtime f for f in *ins]
+		itimes = [mtime f for f in *ins]
 		for i=1, #@ins
 			error "Can't build #{@name}: missing inputs" unless itimes[i]
 
-		outs=if @name!=name
+		outs = if @name!=name
 			[patsubst name, @name, elem for elem in *@outs]
 		else
 			@outs
-		otimes=[mtime f for f in *outs]
+		otimes = [mtime f for f in *outs]
 		for i=1, #@outs
 			return true if not otimes[i]
 
@@ -128,10 +131,10 @@ class BuildObject
 
 error "Need Lua >=5.2" if setfenv
 
-targets={}
-defaulttarget='all'
+targets = {}
+defaulttarget = 'all'
 
-buildscope=
+buildscope =
 	default: (target) ->
 		defaulttarget=target.name
 		target
@@ -139,27 +142,27 @@ buildscope=
 		insert targets, target.name
 		target
 	target: (name, params) ->
-		tout=flatten params.out
-		tin=flatten params.in
-		tdeps=flatten params.deps
+		tout = flatten params.out
+		tin = flatten params.in
+		tdeps = flatten params.deps
 		for f in *flatten params.from
 			insert tin, f
 			insert tdeps, f
 		BuildObject name, tout, tin, tdeps, params.fn
 	:Command
-buildscope[k]=fn for k, fn in pairs util
+buildscope[k] = fn for k, fn in pairs util
 
 setmetatable buildscope,
 	__index: (k) =>
-		global=rawget _G, k
+		global = rawget _G, k
 		return global if global
 		(...) -> Command k, ...
 
-file=first {'Build.moon', 'Buildfile.moon', 'Build', 'Buildfile'}, exists
+file = first {'Build.moon', 'Buildfile.moon', 'Build', 'Buildfile'}, exists
 error "No Build.moon or Buildfile found" unless file
-buildfn=loadwithscope file, buildscope
+buildfn = loadwithscope file, buildscope
 error "Failed to load build function" unless buildfn
-ok, err=pcall buildfn
+ok, err = pcall buildfn
 unless ok
 	if err
 		io.stderr\write err, '\n'