[ This is off the top of my head and untested. ]

SubLevelOptions, despite its name, only allows for one sublevel option.
You perhaps want something more like:

SublevelOptionsMaybe ::= SublevelOptions
SubLevelOptions ::= SubLevelOption+
SublevelOptionsMaybe ::=

SublevelOption      ::=  SUBLEVELOPTIONS

There are alternative ways to write the above that are more elegant and
probably better, but I think it conveys the idea.  Again, untested.

I hope this helps, jeffrey

On Mon, Feb 19, 2018 at 11:49 AM, <stefan.gottsch...@gmail.com> wrote:

> I'm scarcely more than a novice with Marpa, so please forgive me if I'm
> asking for too much or being naive.
>
> A sample of my legacy DSL looks like this:
>
> sublevel: -only "-R[SUNLF]{0,1}\d+\s" -testargsmore -foo
>
> {
>
>   < test { foo } >
>
> }
>
>
> The *sublevel:* is supposed to be a key word, introducing a kind of
> statement.
>
> Following the key word is a bunch of nearly arbitrary text (containing
> options and parameters), terminated by a {}-delimited body.  So the overall
> structure is this:
>
> *sublevel:* *<options>*
> *{*
>     *<more statements>*
> *}*
>
>
> So, the open curly signals the end of the *<options>* and the start of
> the body.
>
> This legacy DSL allows curlies inside the *<options>* provided they are
> quoted (single or double) or escaped.  So, the curlies in *{0,1}* should
> not be interpreted as special, but taken verbatim.
>
> I studied the string grammar listed in https://gist.github.com/
> jddurand/8d3238c22731a85eb890 and used it as a guide for my development
> for the grammar I list below.  In particular, that example taught me that
> L0 rules permit alternative productions, and also allow sequences.  Anyway,
> the portion of the grammar in ALL CAPS was derived from that example.
>
> But, I get this "No lexeme" error when it hits the first dquote, and I
> cannot figure out why!
>
> Setting trace_terminals option
> Setting trace_values option
> Discarded lexeme L1c1: whitespace
> Accepted lexeme L2c1-9 e1: 'sublevel:'; value="sublevel:"
> Accepted lexeme L2c1-9 e1: 'sublevel:'; value="sublevel:"
> Accepted lexeme L2c10-16 e2: SUBLEVELOPTIONS; value=" -only "
> ****** FAILED TO PARSE ******
> MSG:
> Error in SLIF parse: No lexeme found at line 2, column 17
> * String before error: \nsublevel: -only\s
> * The error was at line 2, column 17, and at character 0x0022 '"', ...
> * here: "-R[SUNLF]{0,1}\\d+\\s" -testargsmore -foo\n{\n  <
> Marpa::R2 exception at ./marpa_bnf_1.pl line 31.
>
>
> I would be grateful for any insights.
>
> I intended that my sample input would have been interpreted, at some depth
> of productions, as
>
> *sublevel:* *SublevelOptions*
> *{*
> *  NamedBlockList*
> *}*
>
>
> and I thought that the SublevelOptions
>
>  -only "-R[SUNLF]{0,1}\d+\s" -testargsmore -foo
>
> would decompose into
>
> STRING_UNQUOTED = ( -only )
> STRING_DQUOTED = ("-R[SUNLF]{0,1}\d+\s")
> STRING_UNQUOTED = ( -testargsmore -foo)
>
>
> and I failed to see why it doesn't do so.  Instead, Marpa tells me it
> doesn't know what to do when it sees that dquote.
>
> Below is my full grammar.
>
> :default ::= action => [name, start, length, values]
> lexeme default = latm => 1
>
> File ::= BodyStatements
> File ::=
>
> BodyStatements ::= BodyStatement+
>
> BodyStatement ::=
>     Sublevel
>   | SingleTest
>
>
> Sublevel ::= ('sublevel:') SublevelOptionsMaybe ('{') BodyStatements ('}')
> Sublevel ::= ('sublevel:') SublevelOptionsMaybe ('{') ('}')
> SublevelOptionsMaybe ::= SublevelOptions
> SublevelOptionsMaybe ::=
>
> SublevelOptions      ::=  SUBLEVELOPTIONS
>
> SUBLEVELOPTIONS             ~ SUBLEVELOPTIONS_STRING+
>
> SUBLEVELOPTIONS_STRING      ~ STRING_UNQUOTED
>                             | STRING_SQUOTED
>                             | STRING_DQUOTED
>
> STRING_UNQUOTED             ~ CHAR_UNQUOTED+
> CHAR_UNQUOTED               ~ [^"'\}\{;\\\n]
> CHAR_UNQUOTED               ~ ES
>
> STRING_SQUOTED              ~ SQUOTE STRING_INSIDE_SQUOTES SQUOTE
> STRING_INSIDE_SQUOTES       ~ CHAR_INSIDE_SQUOTES*
> CHAR_INSIDE_SQUOTES         ~ [^'\\]
> CHAR_INSIDE_SQUOTES         ~ [\\] [']
> SQUOTE                      ~ [']
>
> STRING_DQUOTED              ~ DQUOTE STRING_INSIDE_DQUOTES DQUOTE
> STRING_INSIDE_DQUOTES       ~ CHAR_INSIDE_DQUOTES*
> CHAR_INSIDE_DQUOTES         ~ [^"\\\n]
> CHAR_INSIDE_DQUOTES         ~ [\\] [^#]
> DQUOTE                      ~ ["]
>
> ES                          ~ [\\] [\\'"\{\};]
>
> NamedBlockList ::= NamedBlock+
> NamedBlock ::= ArgTag ('{') ArgBodyMaybe ('}')
> ArgBodyMaybe ::= ArgBody
> ArgBodyMaybe ::=
> ArgBody ~ [^\{\}]+
> ArgTag ~ [\w]+
>
> SingleTest ::=
>     SingleSimpleTest
>
> SingleSimpleTest ::= ('<') NamedBlockList ('>')
>
> # whitespace
> :discard ~ whitespace
> whitespace ~ [\s]+
>
>
>
>
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