From: Jean Privat <jean@pryen.org>
Date: Mon, 21 Jul 2014 19:59:36 +0000 (-0400)
Subject: comp: compile `lazy` in the getter
X-Git-Tag: v0.6.7~30^2~5
X-Git-Url: http://nitlanguage.org

comp: compile `lazy` in the getter

For primitive and nullables, lazy is implemented with an additionnal
boolean attribute used as a guard.
The guard is also update in the setter.

For nonnullable val*, lazy is implemented with issset that is currently
only correctly implemented in this subcase.

One isset has a good implementation, the guard implemnatation can be
removed.

Signed-off-by: Jean Privat <jean@pryen.org>
---

diff --git a/src/abstract_compiler.nit b/src/abstract_compiler.nit
index ac308b2..fb376ac 100644
--- a/src/abstract_compiler.nit
+++ b/src/abstract_compiler.nit
@@ -2123,11 +2123,44 @@ redef class AAttrPropdef
 	do
 		if mpropdef == mreadpropdef then
 			assert arguments.length == 1
-			var res = v.read_attribute(self.mpropdef.mproperty, arguments.first)
+			var res
+			if is_lazy then
+				var nexpr = n_expr
+				assert nexpr != null
+				var set
+				var ret = self.mpropdef.static_mtype
+				var useiset = ret.ctype == "val*" and not ret isa MNullableType
+				var guard = self.mlazypropdef.mproperty
+				if useiset then
+					set = v.isset_attribute(self.mpropdef.mproperty, arguments.first)
+				else
+					set = v.read_attribute(guard, arguments.first)
+				end
+				v.add("if(likely({set})) \{")
+				res = v.read_attribute(self.mpropdef.mproperty, arguments.first)
+				v.add("\} else \{")
+				var value = v.expr(nexpr, self.mpropdef.static_mtype)
+				v.write_attribute(self.mpropdef.mproperty, arguments.first, value)
+				v.assign(res, value)
+				if not useiset then
+					var true_v = v.new_expr("1", v.bool_type)
+					v.write_attribute(guard, arguments.first, true_v)
+				end
+				v.add("\}")
+			else
+				res = v.read_attribute(self.mpropdef.mproperty, arguments.first)
+			end
 			v.assign(v.frame.returnvar.as(not null), res)
 		else if mpropdef == mwritepropdef then
 			assert arguments.length == 2
 			v.write_attribute(self.mpropdef.mproperty, arguments.first, arguments[1])
+			if is_lazy then
+				var ret = self.mpropdef.static_mtype
+				var useiset = ret.ctype == "val*" and not ret isa MNullableType
+				if not useiset then
+					v.write_attribute(self.mlazypropdef.mproperty, arguments.first, v.new_expr("1", v.bool_type))
+				end
+			end
 		else
 			abort
 		end
@@ -2136,7 +2169,7 @@ redef class AAttrPropdef
 	fun init_expr(v: AbstractCompilerVisitor, recv: RuntimeVariable)
 	do
 		var nexpr = self.n_expr
-		if nexpr != null then
+		if nexpr != null and not is_lazy then
 			var oldnode = v.current_node
 			v.current_node = self
 			var old_frame = v.frame