added `from`, fixes #2

Build.moon

@@ -6,11 +6,12 @@ MAIN         = "#{BINARY}.moon"
 MAIN_LUA     = patsubst MAIN, '%.moon', '%.lua'
 OUT_C        = patsubst MAIN, '%.moon', '%.lua.c'
 PREFIX       = env 'PREFIX', '/usr/local'
+INSTALL_LOC  = "#{PREFIX}/bin"
 
 default public target 'all', deps: BINARY
 
-public target 'install', deps: 'moonbuild', in: 'moonbuild', fn: =>
+public target 'install', from: BINARY, out: INSTALL_LOC, fn: =>
-	-install @infile, "#{PREFIX}/bin"
+	-install @infile, @outfile
 
 public target 'clean', fn: =>
 	-rm '-f', OUT_LUA
@@ -24,7 +25,7 @@ public target 'info', fn: =>
 	#echo "Compiled lua:", OUT_LUA
 	#echo "Binary:", BINARY
 
-target BINARY, out: {BINARY, OUT_C}, in: OUT_LUA, deps: OUT_LUA, fn: =>
+target BINARY, out: {BINARY, OUT_C}, from: OUT_LUA, fn: =>
 	-luastatic MAIN_LUA, OUT_LUA, '-I/usr/include/lua5.3', '-llua5.3'
 
 foreach OUT_LUA, (file) ->

README.md

@@ -20,10 +20,10 @@ First, you'll need a `Build.moon`, `Buildfile.moon`, `Build` or `Buildfile` in t
 Then, you'll need a few `target`s, and ideally a `default target` (or the default target will be `all`). `public target`s will be listed by `moonbuild -l`.
 To execute a command, you can use either `-cmd` or `#cmd` (the former will print it before executing it, the later won't).
 
-### `[default] [public] target <name> [deps: <deps>] [in: <inputs>] [out: <outputs>] [fn: <code>]`
+### `[default] [public] target <name> [deps: <deps>] [in: <inputs>] [out: <outputs>] [from: <from>] [fn: <code>]`
 Define a new target, and give it a list of depenancies, inputs, outputs and a function to run to build it.
 
-`deps`, `in` and `out` can be either strings or tables. `name` must be a string and `code` must be a function, that will be given a table with the following fields:
+`deps`, `in` and `out` can be either strings or tables. `from` acts like both `in` and `deps`. `name` must be a string and `code` must be a function, that will be given a table with the following fields:
 - `name`: the name of the target
 - `ins`: the table of inputs
 - `infile`: the first input

moonbuild.moon

@@ -101,7 +101,13 @@ buildscope=
 		insert targets, target.name
 		target
 	target: (name, params) ->
-		BuildObject name, (flatten params.out), (flatten params.in), (flatten params.deps), params.fn
+		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
 buildscope[k]=fn for k, fn in pairs util
 
 setmetatable buildscope,