From 035bb2fc6002a15205a3cf5a1d3feaf8c3471a53 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Fri, 25 Jul 2025 16:14:35 -0400
Subject: [PATCH] Fix matching lexer patterns containing a negated character
 class which includes a backslash-escaped sequence that matches more than one
 character

---
 lib/propane/regex/unit.rb      |  7 ++-----
 spec/propane/lexer/dfa_spec.rb |  9 +++++++++
 spec/propane/regex_spec.rb     | 17 +++++++++++++++++
 3 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/lib/propane/regex/unit.rb b/lib/propane/regex/unit.rb
index a286f6c..e68658f 100644
--- a/lib/propane/regex/unit.rb
+++ b/lib/propane/regex/unit.rb
@@ -92,11 +92,8 @@ class Propane
         @units = []
         @negate = false
       end
-      def initialize
-        @units = []
-      end
-      def method_missing(*args)
-        @units.__send__(*args)
+      def method_missing(*args, &block)
+        @units.__send__(*args, &block)
       end
       def <<(thing)
         if thing.is_a?(CharacterClassUnit)
diff --git a/spec/propane/lexer/dfa_spec.rb b/spec/propane/lexer/dfa_spec.rb
index 8f5789d..555a271 100644
--- a/spec/propane/lexer/dfa_spec.rb
+++ b/spec/propane/lexer/dfa_spec.rb
@@ -126,6 +126,15 @@ EOF
     ]
     expect(run(<<EOF, ";")).to eq expected
 token semicolon /;/;
+EOF
+  end
+
+  it "matches a negated character class" do
+    expected = [
+      ["pattern", "/abc/"],
+    ]
+    expect(run(<<EOF, "/abc/")).to eq expected
+token pattern /\\/[^\\s]*\\//;
 EOF
   end
 end
diff --git a/spec/propane/regex_spec.rb b/spec/propane/regex_spec.rb
index c85a640..397f577 100644
--- a/spec/propane/regex_spec.rb
+++ b/spec/propane/regex_spec.rb
@@ -189,6 +189,23 @@ class Propane
       expect(ccu[0].first).to eq "x".ord
     end
 
+    it "parses a negated character class with inner character classes" do
+      regex = Regex.new("[^x\\sz]")
+      expect(regex.unit).to be_a Regex::AlternatesUnit
+      expect(regex.unit.alternates.size).to eq 1
+      expect(regex.unit.alternates[0]).to be_a Regex::SequenceUnit
+      seq_unit = regex.unit.alternates[0]
+      expect(seq_unit.size).to eq 1
+      expect(seq_unit[0]).to be_a Regex::CharacterClassUnit
+      ccu = seq_unit[0]
+      expect(ccu.negate).to be_truthy
+      expect(ccu.size).to eq 8
+      expect(ccu[0]).to be_a Regex::CharacterRangeUnit
+      expect(ccu[0].first).to eq "x".ord
+      expect(ccu[1].first).to eq " ".ord
+      expect(ccu[7].first).to eq "z".ord
+    end
+
     it "parses - as a plain character at beginning of a character class" do
       regex = Regex.new("[-9]")
       expect(regex.unit).to be_a Regex::AlternatesUnit