From 16f0234f091f71b4ac944d16464ab12b7108735c Mon Sep 17 00:00:00 2001
From: Jean Privat <jean@pryen.org>
Date: Fri, 23 Aug 2013 15:25:37 -0400
Subject: [PATCH 1/1] nitg&i:  handle new `implies` operator

Signed-off-by: Jean Privat <jean@pryen.org>
---
 src/abstract_compiler.nit |   15 +++++++++++++++
 src/flow.nit              |   15 +++++++++++++++
 src/naive_interpreter.nit |   10 ++++++++++
 src/transform.nit         |    7 +++++++
 src/typing.nit            |    9 +++++++++
 5 files changed, 56 insertions(+)

diff --git a/src/abstract_compiler.nit b/src/abstract_compiler.nit
index fa14030..9bf87bd 100644
--- a/src/abstract_compiler.nit
+++ b/src/abstract_compiler.nit
@@ -2020,6 +2020,21 @@ redef class AOrExpr
 	end
 end
 
+redef class AImpliesExpr
+	redef fun expr(v)
+	do
+		var res = v.new_var(self.mtype.as(not null))
+		var i1 = v.expr_bool(self.n_expr)
+		v.add("if (!{i1}) \{")
+		v.add("{res} = 1;")
+		v.add("\} else \{")
+		var i2 = v.expr_bool(self.n_expr2)
+		v.add("{res} = {i2};")
+		v.add("\}")
+		return res
+	end
+end
+
 redef class AAndExpr
 	redef fun expr(v)
 	do
diff --git a/src/flow.nit b/src/flow.nit
index 05a40b9..a18da43 100644
--- a/src/flow.nit
+++ b/src/flow.nit
@@ -485,6 +485,21 @@ redef class AOrExpr
 	end
 end
 
+redef class AImpliesExpr
+	redef fun accept_flow_visitor(v)
+	do
+		var after_expr = v.visit_expr(self.n_expr)
+
+		v.current_flow_context = after_expr.when_true
+		var after_expr2 = v.visit_expr(self.n_expr2)
+
+		var merge_true = v.make_merge_flow(after_expr.when_false, after_expr2.when_true)
+		merge_true.name = "OR TRUE"
+
+		v.make_true_false_flow(merge_true, after_expr2.when_false)
+	end
+end
+
 redef class AAndExpr
 	redef fun accept_flow_visitor(v)
 	do
diff --git a/src/naive_interpreter.nit b/src/naive_interpreter.nit
index ba80cd9..592c90a 100644
--- a/src/naive_interpreter.nit
+++ b/src/naive_interpreter.nit
@@ -1320,6 +1320,16 @@ redef class AOrExpr
 	end
 end
 
+redef class AImpliesExpr
+	redef fun expr(v)
+	do
+		var cond = v.expr(self.n_expr)
+		if cond == null then return null
+		if not cond.is_true then return v.true_instance
+		return v.expr(self.n_expr2)
+	end
+end
+
 redef class AAndExpr
 	redef fun expr(v)
 	do
diff --git a/src/transform.nit b/src/transform.nit
index af19ef6..f3200fa 100644
--- a/src/transform.nit
+++ b/src/transform.nit
@@ -128,6 +128,13 @@ redef class AOrExpr
 	end
 end
 
+redef class AImpliesExpr
+	redef fun accept_transform_visitor(v)
+	do
+		# TODO
+	end
+end
+
 redef class AAndExpr
 	# `x and y` is replaced with `if x then y else x`
 	redef fun accept_transform_visitor(v)
diff --git a/src/typing.nit b/src/typing.nit
index 3c11789..be3b2b0 100644
--- a/src/typing.nit
+++ b/src/typing.nit
@@ -942,6 +942,15 @@ redef class AOrExpr
 	end
 end
 
+redef class AImpliesExpr
+	redef fun accept_typing(v)
+	do
+		v.visit_expr_bool(n_expr)
+		v.visit_expr_bool(n_expr2)
+		self.mtype = v.type_bool(self)
+	end
+end
+
 redef class AAndExpr
 	redef fun accept_typing(v)
 	do
-- 
1.7.9.5