X-Git-Url: http://nitlanguage.org

diff --git a/src/parser/parser_work.nit b/src/parser/parser_work.nit
index 41d6741..a344fc7 100644
--- a/src/parser/parser_work.nit
+++ b/src/parser/parser_work.nit
@@ -141,12 +141,13 @@ class Parser
 				var node1 = pop
 				assert node1 isa AModule
 				var node = new Start(node1, node2)
-				(new ComputeProdLocationVisitor).enter_visit(node)
+				node2.parent = node
+				(new ComputeProdLocationVisitor(lexer.file.first_token)).enter_visit(node)
 				return node
 			else if action_type == 3 then # ERROR
 				# skip injected tokens
 				while not isset token._location do token = lexer.next
-				var node2 = new AParserError.init_parser_error("Syntax error: unexpected {token}.", token.location, token)
+				var node2 = new AParserError.init_parser_error("Syntax Error: unexpected {token}.", token.location, token)
 				var node = new Start(null, node2)
 				return node
 			end
@@ -176,21 +177,55 @@ end
 # Uses existing token locations to infer location of productions.
 private class ComputeProdLocationVisitor
 	super Visitor
+
+	# The current (or starting) cursor on the token sequence used to collect loose tokens
+	var token: nullable Token
+
 	# Currently visited productions that need a first token
 	var need_first_prods = new Array[Prod]
 
 	# Already visited epsilon productions that waits something after them
 	var need_after_epsilons = new Array[Prod]
 
-	# Location of the last visited token in the current production
-	var last_location: nullable Location = null
+	# The last visited token in the current production
+	var last_token: nullable Token = null
 
 	redef fun visit(n: ANode)
 	do
 		if n isa Token then
+			# Skip injected tokens
 			if not isset n._location then return
+
+			# Collect loose tokens (not in the AST) and attach them to token in the AST
+			var cursor = token
+			if n != cursor then
+				var lt = last_token
+				# In order, we have the tokens:
+				# * `lt` the previous visited token in the AST (if any)
+				# * then `cursor` the loose tokens to attach
+				# * then `n` the current visited token in the AST
+
+				# In the following, we advance `cursor` to add them to `lt.next_looses` or to `n.prev_looses`.
+				if lt != null then
+					var ltl = lt.location.line_end
+					# floating tokens on the same line of a AST-token follows it
+					while cursor != null and cursor != n and ltl == cursor.location.line_start do
+						cursor.is_loose = true
+						lt.next_looses.add cursor
+						cursor = cursor.next_token
+					end
+				end
+				# other loose tokens precede the next AST-token
+				while cursor != null and cursor != n do
+					cursor.is_loose = true
+					n.prev_looses.add cursor
+					cursor = cursor.next_token
+				end
+			end
+			token = n.next_token
+
 			var loc = n._location
-			_last_location = loc
+			_last_token = n
 
 			# Add a first token to productions that need one
 			if not _need_first_prods.is_empty then
@@ -217,10 +252,13 @@ private class ComputeProdLocationVisitor
 			var startl = n._first_location
 			if startl != null then
 				# Non-epsilon production
-				var endl = _last_location
-				assert endl != null
+				var endl = _last_token.location
 
-				n.location = new Location(startl.file, startl.line_start, endl.line_end, startl.column_start, endl.column_end)
+				if startl == endl then
+					n.location = startl
+				else
+					n.location = new Location(startl.file, startl.line_start, endl.line_end, startl.column_start, endl.column_end)
+				end
 
 				if not _need_after_epsilons.is_empty then
 					var loc = new Location(endl.file, endl.line_end, endl.line_end, endl.column_end, endl.column_end)