allow dollar sign as another variant of ^[ (discard all arguments or return)

 * some classic TECOs have this
 * just like ^[, dollar works as a command only, not as a string terminator
 * it improves the readability of macros using printable characters only
 * it closes a gap in the language by allowing $$ (double-dollar) and
   ^[$ as printable ways to write the return from macro command.
   ^[^[ was not and is not possible.
 * since command line termination is a regular interactive return-command
   in SciTECO, double-dollar will also terminate the command line now.
   This will be allowed unless it turns out to be a cause of trouble.
 * The handling of unterminated commands has been cleaned up by
   introducing State::end_of_macro().
   Most commands (and thus states) except the start state cannot be
   valid at the end of a macro since this indicates an unterminated/incomplete
   command.
   All lookahead-commands (currently only ^[) will end implicitly
   at the end of a macro and so will need a way to perform their action.
   The virtual method allows these actions to be defined with the rest
   of the state's implementation.

1 files changed, 15 insertions, 0 deletions

diff --git a/src/parser.h b/src/parser.h
index 3356600..a7059a9 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -66,6 +66,17 @@ public:
 	 */
 	virtual void refresh(void) {}
 
+	/**
+	 * Called at the end of a macro.
+	 * Most states/commands are not allowed to end unterminated
+	 * at the end of a macro.
+	 */
+	virtual void
+	end_of_macro(void)
+	{
+		throw Error("Unterminated command");
+	}
+
 protected:
 	static bool eval_colon(void);
 
@@ -209,6 +220,8 @@ private:
 	tecoBool delete_words(tecoInt n);
 
 	State *custom(gchar chr);
+
+	void end_of_macro(void) {}
 };
 
 class StateControl : public State {
@@ -233,6 +246,8 @@ public:
 
 private:
 	State *custom(gchar chr);
+
+	void end_of_macro(void);
 };
 
 class StateFCommand : public State {