From fa5db8e89225622a1ee7a5d802f253d07884b13e Mon Sep 17 00:00:00 2001
From: Taylan Kammer <taylan.kammer@gmail.com>
Date: Mon, 25 May 2026 20:48:36 +0200
Subject: Grammar, parser, and doc improvements.

---
 docs/c1/grammar/abnf.txt | 12 +++++++-----
 docs/c1/grammar/index.md |  6 ++++++
 docs/c1/grammar/zbnf.txt | 11 ++++++-----
 3 files changed, 19 insertions(+), 10 deletions(-)

(limited to 'docs/c1/grammar')

diff --git a/docs/c1/grammar/abnf.txt b/docs/c1/grammar/abnf.txt
index 6daaceb..7424f41 100644
--- a/docs/c1/grammar/abnf.txt
+++ b/docs/c1/grammar/abnf.txt
@@ -19,7 +19,7 @@ Blank         = HTAB / LF / %x0b / %x0c / CR / SP / Comment
 Trail         = SkipLine / SkipUnit / ";" "~" *Blank
 
 
-Datum         = BareString / DottedStr / CladDatum / Rune / RuneStr
+Datum         = BareString / SpecialStr / CladDatum / Rune / RuneStr
               / RuneDotStr / RuneClad / LabelRef / LabelDef / HashStr
               / HashDotStr / HashClad / QuoteExpr / JoinExpr
 
@@ -36,7 +36,7 @@ AnyButLF      = %x00-09 / %x0b-ff
 
 BareString    = BareChar *( BareChar / Numeric )
 
-DottedStr     = ( "." / Numeric ) *( "." / Numeric / BareChar )
+SpecialStr    = SpecStrChar *( SpecStrChar / BareChar )
 
 CladDatum     = "|" *( PipeStrChar / "\" StringEsc ) "|"
               / DQUOTE *( QuotStrChar / "\" StringEsc ) DQUOTE
@@ -48,7 +48,7 @@ Rune          = "#" RuneName
 
 RuneStr       = "#" RuneName "\" BareString
 
-RuneDotStr    = "#" RuneName "\" DottedStr
+RuneDotStr    = "#" RuneName "\" SpecialStr
 
 RuneClad      = "#" RuneName CladDatum
 
@@ -58,7 +58,7 @@ LabelDef      = "#" "%" Label "=" Datum
 
 HashStr       = "#" "\" BareString
 
-HashDotStr    = "#" "\" DottedStr
+HashDotStr    = "#" "\" SpecialStr
 
 HashClad      = "#" CladDatum
 
@@ -73,10 +73,12 @@ JoinExpr      = Datum RJoinDatum
 
 
 BareChar      = "!" / "$" / "%" / "*" / "/" / "<" / "=" / ">"
-              / "?" / "@" / "^" / "_" / "~" / ALPHA
+              / "?" / "^" / "_" / "~" / ALPHA
 
 Numeric       = "+" / "-" / DIGIT
 
+SpecStrChar   = "." / ":" / Numeric
+
 PipeStrChar   = %x00-5b / %x5d-7b / %x7d-ff ; any but "|" or "\"
 
 QuotStrChar   = %x00-21 / %x23-5b / %x5d-ff ; any but DQUOTE or "\"
diff --git a/docs/c1/grammar/index.md b/docs/c1/grammar/index.md
index d70021a..8fefe0e 100644
--- a/docs/c1/grammar/index.md
+++ b/docs/c1/grammar/index.md
@@ -74,6 +74,12 @@ The following limits are not represented in the grammar:
    want to use the ABNF to generate a parser anyway.)
 
 
+## At-quoted strings
+
+The mechanism of at-quoted strings is not represented in any of the
+grammars, since it essentially has 256 variants.
+
+
 ## Stream-parsing strategy
 
 The parser consumes one `Unit` from the input stream every time it's
diff --git a/docs/c1/grammar/zbnf.txt b/docs/c1/grammar/zbnf.txt
index 551c319..002e027 100644
--- a/docs/c1/grammar/zbnf.txt
+++ b/docs/c1/grammar/zbnf.txt
@@ -22,7 +22,7 @@ SkipLine      : ( ~LF )* [LF]
 OneDatum      : BareString | CladDatum
 
 
-BareString    : ( '.' | '+' | '-' | DIGIT ) ( BareChar | '.' )*
+BareString    : SpecBareChar ( BareChar | JoinChar )*
               | BareChar+
 
 CladDatum     : PipeStr | QuoteStr | HashExpr | QuoteExpr | List
@@ -33,16 +33,17 @@ HashExpr      : '#' ( RuneExpr | LabelExpr | HashDatum )
 QuoteExpr     : "'" Datum | '`' Datum | ',' Datum
 List          : ParenList | SquareList | BraceList
 
+SpecBareChar  : '+' | '-' | JoinChar | DIGIT
+
 BareChar      : ALPHA | DIGIT
-              | '!' | '$' | '%' | '*' | '+'
-              | '-' | '/' | '<' | '=' | '>'
-              | '?' | '@' | '^' | '_' | '~'
+              | '!' | '$' | '%' | '*' | '+' | '-' | '/'
+              | '<' | '=' | '>' | '?' | '^' | '_' | '~'
 
 PipeStrChar   : ~( '|' | '\' )
 QuotStrChar   : ~( '"' | '\' )
 
 StringEsc     : '\' | '|' | '"' | ( HTAB | SP )* LF ( HTAB | SP )*
-              | 'a' | 'b' | 't' | 'n' | 'v' | 'f' | 'r' | 'e'
+              | '0' | 'a' | 'b' | 't' | 'n' | 'v' | 'f' | 'r' | 'e'
               | 'x' HexByte+ ';'
               | 'u' UnicodeSV ';'
 
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