first draft of commandline-editing commands ({ and } as in VideoTECO)

 * simplified traditional commandline editing. no need to extend cmdline string one character
   at a time when inserting multiple. instead there's a marker (cmdline_pos) specifying the macro
   length to execute in a "step" and also the anchor for generating undo tokens
 * implementation does not yet work in macro calls
 * while editing the commandline, other buffers/registers may not be edited
   (need push-down-list and auxiliary q-register)

5 files changed, 89 insertions, 28 deletions

diff --git a/src/cmdline.cpp b/src/cmdline.cpp
index 4d9cfd6..6e4c9d3 100644
--- a/src/cmdline.cpp
+++ b/src/cmdline.cpp
@@ -49,6 +49,7 @@ static const gchar *last_occurrence(const gchar *str,
 static inline gboolean filename_is_dir(const gchar *filename);
 
 gchar *cmdline = NULL;
+gint cmdline_pos = 0;
 static gchar *last_cmdline = NULL;
 
 bool quit_requested = false;
@@ -60,7 +61,6 @@ namespace States {
 void
 cmdline_keypress(gchar key)
 {
-	gchar *cmdline_p;
 	const gchar *insert;
 	gchar *echo;
 
@@ -76,28 +76,15 @@ cmdline_keypress(gchar key)
 	insert = process_edit_cmd(key);
 
 	/*
-	 * Parse/execute characters
-	 */
-	if (cmdline) {
-		gint len = strlen(cmdline);
-		cmdline = (gchar *)g_realloc(cmdline, len + strlen(insert) + 1);
-		cmdline_p = cmdline + len;
-	} else {
-		cmdline = (gchar *)g_malloc(strlen(insert) + 1);
-		*cmdline = '\0';
-		cmdline_p = cmdline;
-	}
-
-	/*
-	 * Execute one insertion character, extending cmdline, at a time so
+	 * Parse/execute characters, one at a time so
 	 * undo tokens get emitted for the corresponding characters.
 	 */
-	for (const gchar *p = insert; *p; p++) {
-		*cmdline_p++ = *p;
-		*cmdline_p = '\0';
+	cmdline_pos = cmdline ? strlen(cmdline)+1 : 1;
+	String::append(cmdline, insert);
 
+	while (cmdline_pos <= (gint)strlen(cmdline)) {
 		try {
-			Execute::step(cmdline);
+			Execute::step((const gchar *&)cmdline, cmdline_pos);
 		} catch (...) {
 			/*
 			 * Undo tokens may have been emitted (or had to be)
@@ -105,12 +92,14 @@ cmdline_keypress(gchar key)
 			 * executed so as if the character had never been
 			 * inserted.
 			 */
-			undo.pop(cmdline_p - cmdline);
-			cmdline_p[-1] = '\0';
+			undo.pop(cmdline_pos);
+			cmdline[cmdline_pos-1] = '\0';
 			/* program counter could be messed up */
-			macro_pc = cmdline_p - cmdline - 1;
+			macro_pc = cmdline_pos - 1;
 			break;
 		}
+
+		cmdline_pos++;
 	}
 
 	/*
diff --git a/src/cmdline.h b/src/cmdline.h
index b88599a..8747f63 100644
--- a/src/cmdline.h
+++ b/src/cmdline.h
@@ -25,6 +25,7 @@
 #include "qregisters.h"
 
 extern gchar *cmdline;
+extern gint cmdline_pos;
 extern bool quit_requested;
 
 void cmdline_keypress(gchar key);
diff --git a/src/parser.cpp b/src/parser.cpp
index 37dd055..cb4180e 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -71,9 +71,9 @@ gchar *strings[2] = {NULL, NULL};
 gchar escape_char = '\x1B';
 
 void
-Execute::step(const gchar *macro) throw (State::Error)
+Execute::step(const gchar *&macro, gint &stop_pos) throw (State::Error)
 {
-	while (macro[macro_pc]) {
+	while (macro_pc < stop_pos) {
 #ifdef DEBUG
 		g_printf("EXEC(%d): input='%c'/%x, state=%p, mode=%d\n",
 			 macro_pc, macro[macro_pc], macro[macro_pc],
@@ -91,6 +91,8 @@ Execute::step(const gchar *macro) throw (State::Error)
 void
 Execute::macro(const gchar *macro, bool locals) throw (State::Error)
 {
+	gint macro_len = strlen(macro);
+
 	GotoTable *parent_goto_table = Goto::table;
 	GotoTable macro_goto_table(false);
 
@@ -114,7 +116,7 @@ Execute::macro(const gchar *macro, bool locals) throw (State::Error)
 	}
 
 	try {
-		step(macro);
+		step(macro, macro_len);
 		if (Goto::skip_label)
 			throw State::Error("Label \"%s\" not found",
 					   Goto::skip_label);
@@ -819,6 +821,76 @@ StateStart::custom(gchar chr) throw (Error)
 		break;
 
 	/*
+	 * Command-line editing
+	 */
+	case '{': {
+		void *document;
+
+		BEGIN_EXEC(this);
+		if (!undo.enabled)
+			throw Error("Command-line editing only possible in "
+				    "interactive mode");
+
+		current_save_dot();
+
+		if (ring.current)
+			ring.current->undo_edit();
+		else if (QRegisters::current)
+			QRegisters::current->undo_edit();
+
+		document = (void *)interface.ssm(SCI_CREATEDOCUMENT);
+		interface.ssm(SCI_SETDOCPOINTER, 0, (sptr_t)document);
+		interface.ssm(SCI_ADDTEXT, cmdline_pos-1, (sptr_t)cmdline);
+
+		undo.push_msg(SCI_RELEASEDOCUMENT, 0, (sptr_t)document);
+		break;
+	}
+
+	case '}': {
+		gint size, i;
+		gchar *old_cmdline, *new_cmdline;
+
+		BEGIN_EXEC(this);
+		if (!undo.enabled)
+			throw Error("Command-line editing only possible in "
+				    "interactive mode");
+
+		size = interface.ssm(SCI_GETLENGTH) + 1;
+		new_cmdline = (gchar *)g_malloc(size);
+		interface.ssm(SCI_GETTEXT, size, (sptr_t)new_cmdline);
+
+		for (i = 0; cmdline[i] && cmdline[i] == new_cmdline[i]; i++);
+		undo.pop(i+1);
+
+		old_cmdline = cmdline;
+		cmdline = new_cmdline;
+		cmdline_pos = i+1;
+		macro_pc = i; /* FIXME */
+
+		while (cmdline_pos <= (gint)strlen(cmdline)) {
+			try {
+				Execute::step((const gchar *&)cmdline, cmdline_pos);
+			} catch (...) {
+				undo.pop(i+1);
+				cmdline = old_cmdline;
+				cmdline[strlen(cmdline)-1] = '\0';
+				g_free(new_cmdline);
+				old_cmdline = NULL;
+				cmdline_pos = i;
+				macro_pc = i-1; /* FIXME */
+				break;
+			}
+
+			cmdline_pos++;
+		}
+
+		g_free(old_cmdline);
+
+		/* state may have changed due to undoing */
+		return States::current;
+	}
+
+	/*
 	 * modifiers
 	 */
 	case '@':
diff --git a/src/parser.h b/src/parser.h
index 69a6d93..8ee15d7 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -253,7 +253,7 @@ extern gchar *strings[2];
 extern gchar escape_char;
 
 namespace Execute {
-	void step(const gchar *macro) throw (State::Error);
+	void step(const gchar *&macro, gint &stop_pos) throw (State::Error);
 	void macro(const gchar *macro, bool locals = true) throw (State::Error);
 	bool file(const gchar *filename, bool locals = true);
 }
diff --git a/src/undo.cpp b/src/undo.cpp
index 82f1eda..1ee7cb4 100644
--- a/src/undo.cpp
+++ b/src/undo.cpp
@@ -20,7 +20,6 @@
 #endif
 
 #include <stdio.h>
-#include <string.h>
 #include <bsd/sys/queue.h>
 
 #include <glib.h>
@@ -50,7 +49,7 @@ UndoStack::push(UndoToken *token)
 #ifdef DEBUG
 		g_printf("UNDO PUSH %p\n", token);
 #endif
-		token->pos = strlen(cmdline);
+		token->pos = cmdline_pos;
 		SLIST_INSERT_HEAD(&head, token, tokens);
 	} else {
 		delete token;