added pipelines, closes #18

moonbuild/core/Pipeline.moon

@@ -0,0 +1,56 @@
+Target = require 'moonbuild.core.Target'
+_ = require 'moonbuild._'
+import flatten, patsubst from _
+
+class Pipeline
+	new: (@ctx) =>
+		@lastsources = {}
+
+	sources: (...) =>
+		@lastsources = flatten @lastsources, ...
+	source: (src) =>
+		@lastsources = flatten @lastsources, src
+
+	step: (name, params) =>
+		public = true
+		public, params = false, name if (type name) == 'table'
+
+		tgttype = if params.pattern
+			error "pattern must be a table with the same format as patsubst" unless (type params.pattern) == 'table' and (type params.pattern[1]) == 'string' and (type params.pattern[2]) == 'string'
+			'pattern'
+		elseif params.output or params.out
+			error "output must be a string" unless (type params.output or params.out) == 'string'
+			'single'
+		else
+			error "invalid step type for pipeline: must be pattern or single (out/output)"
+
+		tgtouts = switch tgttype
+			when 'pattern' then patsubst @lastsources, params.pattern[1], params.pattern[2]
+			when 'single' then params.output or params.out
+
+		tgtpatt = switch tgttype
+			when 'pattern' then params.pattern[2]
+			when 'single' then nil
+
+		tgtins = switch tgttype
+			when 'pattern' then params.pattern[1]
+			when 'single' then @lastsources
+
+		tgtprod = switch tgttype
+			when 'pattern' then params.pattern[2]
+			when 'single' then '%'
+
+		tgt = with Target @ctx, tgtouts, pattern: tgtpatt
+			\depends tgtins
+			\produces tgtprod
+			\fn params.fn or error "pipeline steps need a fn"
+		tgt\mkdirs! if params.mkdirs
+		tgt\sync! if params.sync
+		@ctx\addtarget tgt
+
+		if public
+			@ctx\addtarget with Target @ctx, name
+				\depends tgtouts
+				.public = true
+
+		@lastsources = tgtouts

moonbuild/env/init.moon

@@ -1,5 +1,6 @@
 Target = require 'moonbuild.core.Target'
 Variable = require 'moonbuild.core.Variable'
+Pipeline = require 'moonbuild.core.Pipeline'
 _ = require 'moonbuild._'
 import flatten from _
 
@@ -18,8 +19,8 @@ import flatten from _
 	rawset env, '_G', env
 	rawset env, '_ENV', env
 
-	rawset env, 'var', (name, ...) ->
-		var = Variable name, ...
+	rawset env, 'var', (...) ->
+		var = Variable ...
 		ctx\addvar var
 		rawset varlayer, var.name, var.value
 		var
@@ -29,4 +30,7 @@ import flatten from _
 		ctx\addtarget target
 		target
 
+	rawset env, 'pipeline', ->
+		Pipeline ctx
+
 	env, varlayer