From eb55930264a347d4656aae9d1aa82cc7dc1cfd7f Mon Sep 17 00:00:00 2001
From: Christopher Durham <cad97@cad97.com>
Date: Sun, 10 Dec 2023 20:44:55 -0500
Subject: [PATCH] Update formal grammar for KDL 2.0 (#285)
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Fixes: https://github.com/kdl-org/kdl/issues/284

* Update formal grammar

* Update SPEC.md for KDL 2.0 preview

* Update SPEC.md

Co-authored-by: Christopher Durham <cad97@cad97.com>

---------

Co-authored-by: Tab Atkins Jr <jackalmage@gmail.com>
Co-authored-by: Kat Marchán <kzm@zkat.tech>
---
 SPEC.md | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/SPEC.md b/SPEC.md
index cbd90c7..b06c311 100644
--- a/SPEC.md
+++ b/SPEC.md
@@ -473,12 +473,20 @@ Note that for the purpose of new lines, CRLF is considered _a single newline_.
 ## Full Grammar
 
 ```
-nodes := linespace* (node nodes?)? linespace*
+nodes := (line-space* node)* line-space*
 
-node := ('/-' node-space*)? type? identifier (node-space+ node-prop-or-arg)* (node-space* node-children ws*)? node-space* node-terminator
-node-prop-or-arg := ('/-' node-space*)? (prop | value)
-node-children := ('/-' node-space*)? '{' nodes '}'
-node-space := ws* escline ws* | ws+
+plain-line-space := newline | ws | single-line-comment
+plain-node-space := ws* escline ws* | ws+
+
+line-space := plain-line-space+ ('/-' plain-node-space* node)?
+node-space := plain-node-space+ ('/-' plain-node-space* (node-prop-or-arg | node-children))?
+
+required-node-space := node-space* plain-node-space+
+optional-node-space := node-space*
+
+node := type? identifier (required-node-space node-prop-or-arg)* (required-node-space node-children)? optional-node-space node-terminator
+node-prop-or-arg := prop | value
+node-children := '{' nodes '}'
 node-terminator := single-line-comment | newline | ';' | eof
 
 identifier := string | bare-identifier
@@ -486,7 +494,7 @@ bare-identifier := (unambiguous-ident | numberish-ident | stringish-ident) - key
 unambiguous-ident := (identifier-char - digit - sign - "r") identifier-char*
 numberish-ident := sign ((identifier-char - digit) identifier-char*)?
 stringish-ident := "r" ((identifier-char - "#") identifier-char*)?
-identifier-char := unicode - linespace - [\/(){}<>;[]=,"]
+identifier-char := unicode - line-space - [\/(){}<>;[]=,"]
 keyword := boolean | 'null'
 prop := identifier '=' value
 value := type? (string | number | keyword)
@@ -518,8 +526,6 @@ boolean := 'true' | 'false'
 
 escline := '\\' ws* (single-line-comment | newline)
 
-linespace := newline | ws | single-line-comment
-
 newline := See Table (All line-break white_space)
 
 ws := bom | unicode-space | multi-line-comment