EBNF.parse with :ebnf fails to parse leading '-' inside character classes #17
Description
Describe the bug
When trying to convert the EBNF specification of XML 1.0 found here, I get this exception:
/home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/ebnf-2.6.0/lib/ebnf/peg/parser.rb:256:in 'EBNF::PEG::Parser#parse': ERROR [line: 14] syntax error, expecting :HEX, :SYMBOL, :O_RANGE, :RANGE, :STRING1, :STRING2, "(", :primary, :postfix, :seq (found "[-'()+,./:=?;!*\#@$_%") (EBNF::PEG::Parser::Error)
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/ebnf-2.6.0/lib/ebnf/parser.rb:309:in 'EBNF::Parser#initialize'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/ebnf-2.6.0/lib/ebnf/base.rb:125:in 'Class#new'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/ebnf-2.6.0/lib/ebnf/base.rb:125:in 'EBNF::Base#initialize'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/ebnf-2.6.0/lib/ebnf.rb:29:in 'Class#new'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/ebnf-2.6.0/lib/ebnf.rb:29:in 'EBNF.parse'
from /home/phillipdavis/everyday/dev/mboa/maqam/lib/maqam.rb:16:in 'Maqam::Generator#initialize'
from (irb):2:in 'Class#new'
from (irb):2:in '<main>'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/irb-1.17.0/lib/irb/workspace.rb:110:in 'Kernel#eval'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/irb-1.17.0/lib/irb/workspace.rb:110:in 'IRB::WorkSpace#evaluate'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/irb-1.17.0/lib/irb/context.rb:591:in 'IRB::Context#evaluate_expression'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/irb-1.17.0/lib/irb/context.rb:557:in 'IRB::Context#evaluate'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/irb-1.17.0/lib/irb.rb:217:in 'block (2 levels) in IRB::Irb#eval_input'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/irb-1.17.0/lib/irb.rb:534:in 'IRB::Irb#signal_status'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/irb-1.17.0/lib/irb.rb:209:in 'block in IRB::Irb#eval_input'
from /home/phillipdavis/everyday/dev/mboa/maqam/.gems/ruby/3.4.0/gems/irb-1.17.0/lib/irb.rb:296:in 'block in IRB::Irb#each_top_level_statement'
... 25 levels...
To reproduce
Steps to reproduce the behavior:
EBNF.parse(/* the grammar */).make_bnf
Expected behavior
It converts the grammar into a BNF
Screenshots
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Additional context
Gems included by the bundle:
* addressable (2.8.9)
* ast (2.4.3)
* base64 (0.3.0)
* bcp47_spec (0.2.1)
* bigdecimal (3.3.1)
* date (3.5.1)
* ebnf (2.6.0)
* erb (6.0.2)
* htmlentities (4.4.2)
* io-console (0.8.2)
* irb (1.17.0)
* jennifer (0.0.0 5f71c9d)
* json (2.18.1)
* json-schema (6.1.0)
* language_server-protocol (3.17.0.5)
* link_header (0.0.8)
* lint_roller (1.1.0)
* logger (1.7.0)
* maqam (0.1.0)
* matrix (0.4.3)
* mcp (0.8.0)
* minitest (5.27.0)
* ostruct (0.6.3)
* parallel (1.27.0)
* parser (3.3.10.2)
* pp (0.6.3)
* prettyprint (0.2.0)
* prism (1.9.0)
* psych (5.3.1)
* public_suffix (7.0.5)
* racc (1.8.1)
* rainbow (3.1.1)
* rake (13.3.1)
* rantly (3.0.0)
* rbs (3.10.3)
* rdf (3.3.4)
* rdoc (7.2.0)
* readline (0.0.4)
* regexp_parser (2.11.3)
* reline (0.6.3)
* rubocop (1.85.0)
* rubocop-ast (1.49.0)
* ruby-progressbar (1.13.0)
* scanf (1.0.0)
* stringio (3.2.0)
* sxp (2.0.0)
* tsort (0.2.0)
* unicode-display_width (3.2.0)
* unicode-emoji (4.2.0)
* unicode-types (1.11.0)
phillipdavis in ~/.../mboa/maqam on master✗ λ bundle exec ruby --version
ruby 3.4.8 (2025-12-17 revision 995b59f666) +PRISM [x86_64-linux]To be honest, I'm not sure whether this is a bug in this library or a mistake in the grammar itself. Either way, I'd be willing to put together a pull request.