parser: add `is_loose`, `prev_looses` and `next_looses`

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

fixup loos in nodes

diff --git a/src/parser/parser_nodes.nit b/src/parser/parser_nodes.nit
index fe79ef1..6d7233e 100644 (file)
--- a/src/parser/parser_nodes.nit
+++ b/src/parser/parser_nodes.nit
@@ -311,6 +311,35 @@ abstract class Token
        # May have disappeared in the AST
        var next_token: nullable Token = null
 
+       # Is `self` a token discarded from the AST?
+       #
+       # Loose tokens are not present in the AST.
+       # It means they were identified by the lexer but were discarded by the parser.
+       # It also means that they are not visited or manipulated by AST-related functions.
+       #
+       # Each loose token is attached to the non-loose token that precedes or follows it.
+       # The rules are the following:
+       #
+       # * tokens that follow a non-loose token on a same line are attached to it.
+       #   See `next_looses`.
+       # * other tokens, thus that precede a non-loose token on the same line or the next one,
+       # are attached to this one. See `prev_looses`.
+       #
+       # Loose tokens are mostly end of lines (`TEol`) and comments (`TComment`).
+       # Whitespace are ignored by the lexer, so they are not even considered as loose tokens.
+       # See `blank_before` to get the whitespace that separate tokens.
+       var is_loose = false
+
+       # Loose tokens that precede `self`.
+       #
+       # These tokens start the line or belong to a line with only loose tokens.
+       var prev_looses = new Array[Token] is lazy
+
+       # Loose tokens that follow `self`
+       #
+       # These tokens are on the same line than `self`.
+       var next_looses = new Array[Token] is lazy
+
        # The verbatim blank text between `prev_token` and `self`
        fun blank_before: String
        do