From fdf33c69b73e8c1ea95337566d0e0dc0a3370341 Mon Sep 17 00:00:00 2001
From: Kelvin Sherlock <ksherlock@gmail.com>
Date: Wed, 2 Nov 2022 21:23:22 -0400
Subject: [PATCH] token support for regular expression strings /.../ and \...\.
  Also tokenizer support for =~ and !~ operators.

---
 error.h            | 17 ++++++++++++++++-
 mpw-shell-token.rl | 14 ++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/error.h b/error.h
index 407c5a0..ec7326b 100644
--- a/error.h
+++ b/error.h
@@ -67,6 +67,21 @@ public:
 	{}
 };
 
+class fsstring_error: public mpw_error {
+public:
+	fsstring_error(int status = -3) : 
+	mpw_error(status, "MPW Shell - /s must occur in pairs.")
+	{}
+};
+
+class bsstring_error: public mpw_error {
+public:
+	bsstring_error(int status = -3) : 
+	mpw_error(status, "MPW Shell - \\s must occur in pairs.")
+	{}
+};
+
+
 /*
   these are used for flow-control.
   they do not inherit from std::exception to prevent being caught
@@ -78,4 +93,4 @@ struct continue_command_t {};
 struct exit_command_t { int value = 0; };
 struct quit_command_t {};
 
-#endif
\ No newline at end of file
+#endif
diff --git a/mpw-shell-token.rl b/mpw-shell-token.rl
index e5c739f..0a6d5c3 100644
--- a/mpw-shell-token.rl
+++ b/mpw-shell-token.rl
@@ -37,6 +37,13 @@
 	dchar = escape_seq | (any - escape - ["]);
 	dstring = ["] dchar** ["] $err{ throw dstring_error(); } ;
 
+	# search-forward string
+	fschar = escape_seq | (any - escape - [/]);
+	fsstring = [/] fschar** [/] $err{ throw fsstring_error(); } ;
+
+	# search-backward string
+	bschar = escape_seq | (any - escape - [\\]);
+	bsstring = [\\] bschar** [\\] $err{ throw bsstring_error(); } ;
 
 	action eval { eval }
 
@@ -127,9 +134,16 @@
 			'-=' when eval
 				 %push_token => { tokens.emplace_back("-=", '-='); };
 
+			'=~' when eval
+				 %push_token => { tokens.emplace_back("=~", '=~'); };
+
+			'!~' when eval
+				 %push_token => { tokens.emplace_back("!~", '!~'); };
 
 			sstring => push_string;
 			dstring => push_string;
+			fsstring => push_string;
+			bsstring => push_string;
 			escape_seq => push_string;
 
 			char => push;