From: Jean Privat <jean@pryen.org>
Date: Sat, 11 Oct 2014 02:33:38 +0000 (-0400)
Subject: scope: create two escapemaks in loops
X-Git-Tag: v0.6.10~30^2~4
X-Git-Url: http://nitlanguage.org

scope: create two escapemaks in loops

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

diff --git a/src/astbuilder.nit b/src/astbuilder.nit
index 8e17b4e..f0e0c95 100644
--- a/src/astbuilder.nit
+++ b/src/astbuilder.nit
@@ -176,7 +176,7 @@ redef class ADoExpr
 	private init make
 	do
 		_n_kwdo = new TKwdo
-		escapemark = new EscapeMark(null, false)
+		escapemark = new EscapeMark(null)
 	end
 
 	# Make a new break expression of the given do
@@ -184,7 +184,7 @@ redef class ADoExpr
 	do
 		var escapemark = self.escapemark
 		if escapemark == null then
-			escapemark = new EscapeMark(null, false)
+			escapemark = new EscapeMark(null)
 			self.escapemark = escapemark
 		end
 		return new ABreakExpr.make(escapemark)
diff --git a/src/compiler/abstract_compiler.nit b/src/compiler/abstract_compiler.nit
index a6f6afa..58cb346 100644
--- a/src/compiler/abstract_compiler.nit
+++ b/src/compiler/abstract_compiler.nit
@@ -1266,6 +1266,14 @@ abstract class AbstractCompilerVisitor
 		return name
 	end
 
+	# Insert a C label for associated with an escapemark
+	fun add_escape_label(e: nullable EscapeMark)
+	do
+		if e == null then return
+		if e.escapes.is_empty then return
+		add("BREAK_{escapemark_name(e)}: (void)0;")
+	end
+
 	private var escapemark_names = new HashMap[EscapeMark, String]
 
 	# Return a "const char*" variable associated to the classname of the dynamic type of an object
@@ -2430,11 +2438,7 @@ redef class ASelfExpr
 	redef fun expr(v) do return v.frame.arguments.first
 end
 
-redef class AContinueExpr
-	redef fun stmt(v) do v.add("goto CONTINUE_{v.escapemark_name(self.escapemark)};")
-end
-
-redef class ABreakExpr
+redef class AEscapeExpr
 	redef fun stmt(v) do v.add("goto BREAK_{v.escapemark_name(self.escapemark)};")
 end
 
@@ -2497,10 +2501,7 @@ redef class ADoExpr
 	redef fun stmt(v)
 	do
 		v.stmt(self.n_block)
-		var escapemark = self.escapemark
-		if escapemark != null then
-			v.add("BREAK_{v.escapemark_name(escapemark)}: (void)0;")
-		end
+		v.add_escape_label(break_mark)
 	end
 end
 
@@ -2511,9 +2512,9 @@ redef class AWhileExpr
 		var cond = v.expr_bool(self.n_expr)
 		v.add("if (!{cond}) break;")
 		v.stmt(self.n_block)
-		v.add("CONTINUE_{v.escapemark_name(escapemark)}: (void)0;")
+		v.add_escape_label(continue_mark)
 		v.add("\}")
-		v.add("BREAK_{v.escapemark_name(escapemark)}: (void)0;")
+		v.add_escape_label(break_mark)
 	end
 end
 
@@ -2522,9 +2523,9 @@ redef class ALoopExpr
 	do
 		v.add("for(;;) \{")
 		v.stmt(self.n_block)
-		v.add("CONTINUE_{v.escapemark_name(escapemark)}: (void)0;")
+		v.add_escape_label(continue_mark)
 		v.add("\}")
-		v.add("BREAK_{v.escapemark_name(escapemark)}: (void)0;")
+		v.add_escape_label(break_mark)
 	end
 end
 
@@ -2554,12 +2555,12 @@ redef class AForExpr
 
 			v.stmt(self.n_block)
 
-			v.add("CONTINUE_{v.escapemark_name(escapemark)}: (void)0;")
+			v.add_escape_label(continue_mark)
 			var succ = v.send(v.get_property("successor", variable.mtype), [variable, one])
 			assert succ != null
 			v.assign(variable, succ)
 			v.add("\}")
-			v.add("BREAK_{v.escapemark_name(escapemark)}: (void)0;")
+			v.add_escape_label(break_mark)
 			return
 		end
 
@@ -2595,12 +2596,12 @@ redef class AForExpr
 			abort
 		end
 		v.stmt(self.n_block)
-		v.add("CONTINUE_{v.escapemark_name(escapemark)}: (void)0;")
+		v.add_escape_label(continue_mark)
 		var next_meth = self.method_next
 		assert next_meth != null
 		v.compile_callsite(next_meth, [it])
 		v.add("\}")
-		v.add("BREAK_{v.escapemark_name(escapemark)}: (void)0;")
+		v.add_escape_label(break_mark)
 
 		var method_finish = self.method_finish
 		if method_finish != null then
diff --git a/src/interpreter/naive_interpreter.nit b/src/interpreter/naive_interpreter.nit
index 92b658d..f557227 100644
--- a/src/interpreter/naive_interpreter.nit
+++ b/src/interpreter/naive_interpreter.nit
@@ -112,43 +112,26 @@ class NaiveInterpreter
 	# Set this mark to skip the evaluation until the end of the specified method frame
 	var returnmark: nullable Frame = null
 
-	# Is a break executed?
-	# Set this mark to skip the evaluation until a labeled statement catch it with `is_break`
-	var breakmark: nullable EscapeMark = null
-
-	# Is a continue executed?
-	# Set this mark to skip the evaluation until a labeled statement catch it with `is_continue`
-	var continuemark: nullable EscapeMark = null
+	# Is a break or a continue executed?
+	# Set this mark to skip the evaluation until a labeled statement catch it with `is_escape`
+	var escapemark: nullable EscapeMark = null
 
 	# Is a return or a break or a continue executed?
 	# Use this function to know if you must skip the evaluation of statements
-	fun is_escaping: Bool do return returnmark != null or breakmark != null or continuemark != null
+	fun is_escaping: Bool do return returnmark != null or escapemark != null
 
 	# The value associated with the current return/break/continue, if any.
 	# Set the value when you set a escapemark.
 	# Read the value when you catch a mark or reach the end of a method
 	var escapevalue: nullable Instance = null
 
-	# If there is a break and is associated with `escapemark`, then return true an clear the mark.
-	# If there is no break or if `escapemark` is null then return false.
-	# Use this function to catch a potential break.
-	fun is_break(escapemark: nullable EscapeMark): Bool
-	do
-		if escapemark != null and self.breakmark == escapemark then
-			self.breakmark = null
-			return true
-		else
-			return false
-		end
-	end
-
-	# If there is a continue and is associated with `escapemark`, then return true an clear the mark.
-	# If there is no continue or if `escapemark` is null then return false.
-	# Use this function to catch a potential continue.
-	fun is_continue(escapemark: nullable EscapeMark): Bool
+	# If there is a break/continue and is associated with `escapemark`, then return true and clear the mark.
+	# If there is no break/continue or if `escapemark` is null then return false.
+	# Use this function to catch a potential break/continue.
+	fun is_escape(escapemark: nullable EscapeMark): Bool
 	do
-		if escapemark != null and self.continuemark == escapemark then
-			self.continuemark = null
+		if escapemark != null and self.escapemark == escapemark then
+			self.escapemark = null
 			return true
 		else
 			return false
@@ -1199,20 +1182,7 @@ redef class ASelfExpr
 	end
 end
 
-redef class AContinueExpr
-	redef fun stmt(v)
-	do
-		var ne = self.n_expr
-		if ne != null then
-			var i = v.expr(ne)
-			if i == null then return
-			v.escapevalue = i
-		end
-		v.continuemark = self.escapemark
-	end
-end
-
-redef class ABreakExpr
+redef class AEscapeExpr
 	redef fun stmt(v)
 	do
 		var ne = self.n_expr
@@ -1221,7 +1191,7 @@ redef class ABreakExpr
 			if i == null then return
 			v.escapevalue = i
 		end
-		v.breakmark = self.escapemark
+		v.escapemark = self.escapemark
 	end
 end
 
@@ -1287,7 +1257,7 @@ redef class ADoExpr
 	redef fun stmt(v)
 	do
 		v.stmt(self.n_block)
-		v.is_break(self.escapemark) # Clear the break (if any)
+		v.is_escape(self.break_mark) # Clear the break (if any)
 	end
 end
 
@@ -1299,8 +1269,8 @@ redef class AWhileExpr
 			if cond == null then return
 			if not cond.is_true then return
 			v.stmt(self.n_block)
-			if v.is_break(self.escapemark) then return
-			v.is_continue(self.escapemark) # Clear the break
+			if v.is_escape(self.break_mark) then return
+			v.is_escape(self.continue_mark) # Clear the break
 			if v.is_escaping then return
 		end
 	end
@@ -1311,8 +1281,8 @@ redef class ALoopExpr
 	do
 		loop
 			v.stmt(self.n_block)
-			if v.is_break(self.escapemark) then return
-			v.is_continue(self.escapemark) # Clear the break
+			if v.is_escape(self.break_mark) then return
+			v.is_escape(self.continue_mark) # Clear the break
 			if v.is_escaping then return
 		end
 	end
@@ -1344,8 +1314,8 @@ redef class AForExpr
 				abort
 			end
 			v.stmt(self.n_block)
-			if v.is_break(self.escapemark) then break
-			v.is_continue(self.escapemark) # Clear the break
+			if v.is_escape(self.break_mark) then break
+			v.is_escape(self.continue_mark) # Clear the break
 			if v.is_escaping then break
 			v.callsite(method_next, [iter])
 		end
diff --git a/src/semantize/flow.nit b/src/semantize/flow.nit
index 65f5c7b..733e3d3 100644
--- a/src/semantize/flow.nit
+++ b/src/semantize/flow.nit
@@ -165,7 +165,7 @@ private class FlowVisitor
 	fun merge_continues_to(before_loop: FlowContext, escapemark: nullable EscapeMark)
 	do
 		if escapemark == null then return
-		for b in escapemark.continues do
+		for b in escapemark.escapes do
 			var before = b.before_flow_context
 			if before == null then continue # Forward error
 			before_loop.add_loop(before)
@@ -175,7 +175,7 @@ private class FlowVisitor
 	fun merge_breaks(escapemark: nullable EscapeMark)
 	do
 		if escapemark == null then return
-		for b in escapemark.breaks do
+		for b in escapemark.escapes do
 			var before = b.before_flow_context
 			if before == null then continue # Forward error
 			self.make_merge_flow(self.current_flow_context, before)
@@ -346,7 +346,7 @@ redef class ADoExpr
 	redef fun accept_flow_visitor(v)
 	do
 		super
-		v.merge_breaks(self.escapemark)
+		v.merge_breaks(self.break_mark)
 	end
 end
 
@@ -396,10 +396,10 @@ redef class AWhileExpr
 		var after_block = v.current_flow_context
 
 		before_loop.add_loop(after_block)
-		v.merge_continues_to(after_block, self.escapemark)
+		v.merge_continues_to(after_block, self.continue_mark)
 
 		v.current_flow_context = after_expr.when_false
-		v.merge_breaks(self.escapemark)
+		v.merge_breaks(self.break_mark)
 	end
 end
 
@@ -413,10 +413,10 @@ redef class ALoopExpr
 		var after_block = v.current_flow_context
 
 		before_loop.add_loop(after_block)
-		v.merge_continues_to(after_block, self.escapemark)
+		v.merge_continues_to(after_block, self.continue_mark)
 
 		v.make_unreachable_flow
-		v.merge_breaks(self.escapemark)
+		v.merge_breaks(self.break_mark)
 	end
 end
 
@@ -432,10 +432,10 @@ redef class AForExpr
 		var after_block = v.current_flow_context
 
 		before_loop.add_loop(after_block)
-		v.merge_continues_to(after_block, self.escapemark)
+		v.merge_continues_to(after_block, self.continue_mark)
 
 		v.make_merge_flow(v.current_flow_context, before_loop)
-		v.merge_breaks(self.escapemark)
+		v.merge_breaks(self.break_mark)
 	end
 end
 
diff --git a/src/semantize/scope.nit b/src/semantize/scope.nit
index 30aade4..00702d0 100644
--- a/src/semantize/scope.nit
+++ b/src/semantize/scope.nit
@@ -50,15 +50,12 @@ class EscapeMark
 	# The name of the label (unless the mark is an anonymous loop mark)
 	var name: nullable String
 
-	# Is the mark attached to a loop (loop, while, for)
-	# Such a mark is a candidate to a labelless 'continue' or 'break'
-	var for_loop: Bool
+	# The associated `continue` mark, if any.
+	# If the mark attached to a loop (loop, while, for), a distinct mark is used.
+	private var continue_mark: nullable EscapeMark = null
 
-	# Each 'continue' attached to the mark
-	var continues = new Array[AContinueExpr]
-
-	# Each 'break' attached to the mark
-	var breaks = new Array[ABreakExpr]
+	# Each break/continue attached to the mark
+	var escapes = new Array[AEscapeExpr]
 end
 
 # Visit a npropdef and:
@@ -81,7 +78,7 @@ private class ScopeVisitor
 	end
 
 	# All stacked scope. `scopes.first` is the current scope
-	private var scopes = new List[Scope]
+	var scopes = new List[Scope]
 
 	# Shift and check the last scope
 	fun shift_scope
@@ -176,7 +173,8 @@ private class ScopeVisitor
 		else
 			name = null
 		end
-		var res = new EscapeMark(name, for_loop)
+		var res = new EscapeMark(name)
+		if for_loop then res.continue_mark = new EscapeMark(name)
 		return res
 	end
 
@@ -303,10 +301,12 @@ redef class AContinueExpr
 		super
 		var escapemark = v.get_escapemark(self, self.n_label)
 		if escapemark == null then return # Skip error
-		if not escapemark.for_loop then
+		escapemark = escapemark.continue_mark
+		if escapemark == null then
 			v.error(self, "Error: cannot 'continue', only 'break'.")
+			return
 		end
-		escapemark.continues.add(self)
+		escapemark.escapes.add(self)
 		self.escapemark = escapemark
 	end
 end
@@ -317,19 +317,20 @@ redef class ABreakExpr
 		super
 		var escapemark = v.get_escapemark(self, self.n_label)
 		if escapemark == null then return # Skip error
-		escapemark.breaks.add(self)
+		escapemark.escapes.add(self)
 		self.escapemark = escapemark
 	end
 end
 
 
 redef class ADoExpr
-	# The escape mark associated with the 'do' block
-	var escapemark: nullable EscapeMark
+	# The break escape mark associated with the 'do' block
+	var break_mark: nullable EscapeMark
+
 	redef fun accept_scope_visitor(v)
 	do
-		self.escapemark = v.make_escape_mark(n_label, false)
-		v.enter_visit_block(n_block, self.escapemark)
+		self.break_mark = v.make_escape_mark(n_label, false)
+		v.enter_visit_block(n_block, self.break_mark)
 	end
 end
 
@@ -343,24 +344,34 @@ redef class AIfExpr
 end
 
 redef class AWhileExpr
-	# The escape mark associated with the 'while'
-	var escapemark: nullable EscapeMark
+	# The break escape mark associated with the 'while'
+	var break_mark: nullable EscapeMark
+
+	# The continue escape mark associated with the 'while'
+	var continue_mark: nullable EscapeMark
+
 	redef fun accept_scope_visitor(v)
 	do
 		var escapemark = v.make_escape_mark(n_label, true)
-		self.escapemark = escapemark
+		self.break_mark = escapemark
+		self.continue_mark = escapemark.continue_mark
 		v.enter_visit(n_expr)
 		v.enter_visit_block(n_block, escapemark)
 	end
 end
 
 redef class ALoopExpr
-	# The escape mark associated with the 'loop'
-	var escapemark: nullable EscapeMark
+	# The break escape mark associated with the 'loop'
+	var break_mark: nullable EscapeMark
+
+	# The continue escape mark associated with the 'loop'
+	var continue_mark: nullable EscapeMark
+
 	redef fun accept_scope_visitor(v)
 	do
 		var escapemark = v.make_escape_mark(n_label, true)
-		self.escapemark = escapemark
+		self.break_mark = escapemark
+		self.continue_mark = escapemark.continue_mark
 		v.enter_visit_block(n_block, escapemark)
 	end
 end
@@ -369,8 +380,11 @@ redef class AForExpr
 	# The automatic variables in order
 	var variables: nullable Array[Variable]
 
-	# The escape mark associated with the 'for'
-	var escapemark: nullable EscapeMark
+	# The break escape mark associated with the 'for'
+	var break_mark: nullable EscapeMark
+
+	# The continue escape mark associated with the 'for'
+	var continue_mark: nullable EscapeMark
 
 	redef fun accept_scope_visitor(v)
 	do
@@ -389,7 +403,8 @@ redef class AForExpr
 		end
 
 		var escapemark = v.make_escape_mark(n_label, true)
-		self.escapemark = escapemark
+		self.break_mark = escapemark
+		self.continue_mark = escapemark.continue_mark
 		v.enter_visit_block(n_block, escapemark)
 
 		v.shift_scope