From c67bfcb85cadc1b5b4dfdc036afb6faad4d644cd Mon Sep 17 00:00:00 2001
From: Gears JS <surya@seriousinfinitude.com>
Date: Wed, 15 Feb 2023 10:14:09 +0000
Subject: [PATCH] feat: Add regex parser

---
 lib/parsby/combinators.rb       | 17 +++++++++++++++++
 spec/parsby/combinators_spec.rb |  8 ++++++++
 2 files changed, 25 insertions(+)

diff --git a/lib/parsby/combinators.rb b/lib/parsby/combinators.rb
index d1bbc0e..3e94e24 100644
--- a/lib/parsby/combinators.rb
+++ b/lib/parsby/combinators.rb
@@ -408,5 +408,22 @@ def splicer
         block.call(parse)
       end
     end
+
+    # Matches a regular expression
+    define_combinator :regex do |regex|
+      Parsby.new :regex do |target|
+        position = target.bio.pos
+        target_string = target.bio.read
+
+        unless target_string.match?(regex)
+          raise ExpectationFailed.new target
+        end
+
+        match = target_string.match(regex).to_s
+        target.bio.restore_to(position + match.length)
+
+        match
+      end
+    end
   end
 end
diff --git a/spec/parsby/combinators_spec.rb b/spec/parsby/combinators_spec.rb
index a751d87..c66e7a6 100644
--- a/spec/parsby/combinators_spec.rb
+++ b/spec/parsby/combinators_spec.rb
@@ -505,4 +505,12 @@ def self.parenthesis
       expect { test_parser.parse("ad") }.to raise_error Parsby::ExpectationFailed
     end
   end
+
+  describe "#regex" do
+    it "matches a regex to a string" do
+      expect(regex(/[A-Z][a-z] ./).parse("Hi !")).to eq "Hi !"
+      expect(regex(/\w+@\w+\.\w+/).parse("user@gmail.com extra")).to eq "user@gmail.com"
+      expect {regex(/\w+@\w+\.\w+/).parse("user@gmail")}.to raise_error Parsby::ExpectationFailed
+    end
+  end
 end