parser: ComputeProdLocationVisitor also compute *_looses tokens

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

diff --git a/src/parser/parser_work.nit b/src/parser/parser_work.nit
index 86f44e7..a344fc7 100644 (file)
--- a/src/parser/parser_work.nit
+++ b/src/parser/parser_work.nit
@@ -142,7 +142,7 @@ class Parser
                                assert node1 isa AModule
                                var node = new Start(node1, node2)
                                node2.parent = node
-                               (new ComputeProdLocationVisitor).enter_visit(node)
+                               (new ComputeProdLocationVisitor(lexer.file.first_token)).enter_visit(node)
                                return node
                        else if action_type == 3 then # ERROR
                                # skip injected tokens
@@ -177,6 +177,10 @@ 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]
 
@@ -189,7 +193,37 @@ private class ComputeProdLocationVisitor
        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_token = n