From d63b18fd761897475c8f9ca7269e5a80c7ae6aa9 Mon Sep 17 00:00:00 2001
From: Celestino Amoroso <celestino.amoroso@gmail.com>
Date: Wed, 19 Jun 2024 09:22:40 +0200
Subject: [PATCH] parser.go: SymColon resets the firstToken flag; that is
 needed to specify range indeces that can define negative limits

---
 parser.go | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/parser.go b/parser.go
index e4e5634..19d46e8 100644
--- a/parser.go
+++ b/parser.go
@@ -325,6 +325,14 @@ func couldBeACollection(t *term) bool {
 	return sym == SymList || sym == SymString || sym == SymDict || sym == SymExpression || sym == SymVariable
 }
 
+// func areSymbolsOutOfCtx(tk *Token, ctxTerm *term, syms ...Symbol) bool {
+// 	var areOut = false
+// 	if ctxTerm != nil {
+// 		areOut = tk.IsOneOf(syms)
+// 	}
+// 	return areOut
+// }
+
 func (self *parser) parseGeneral(scanner *scanner, allowForest bool, allowVarRef bool, termSymbols ...Symbol) (tree *ast, err error) {
 	var selectorTerm *term = nil
 	var currentTerm *term = nil
@@ -332,7 +340,7 @@ func (self *parser) parseGeneral(scanner *scanner, allowForest bool, allowVarRef
 	tree = NewAst()
 	firstToken := true
 	// lastSym := SymUnknown
-	for tk = scanner.Next(); err == nil && tk != nil && !tk.IsTerm(termSymbols); tk = scanner.Next() {
+	for tk = scanner.Next(); err == nil && tk != nil && !tk.IsTerm(termSymbols); /*&& !areSymbolsOutOfCtx(tk, selectorTerm, SymColon, SymDoubleColon)*/ tk = scanner.Next() {
 		if tk.Sym == SymComment {
 			continue
 		}
@@ -438,6 +446,10 @@ func (self *parser) parseGeneral(scanner *scanner, allowForest bool, allowVarRef
 			} else {
 				currentTerm, err = tree.addToken2(tk)
 			}
+			if tk.IsSymbol(SymColon) {
+				// Colon outside a selector term acts like a separator
+				firstToken = true
+			}
 		default:
 			currentTerm, err = tree.addToken2(tk)
 		}