refactored =/==/=== command into stdio-commands.c

There will be a lot more commands for terminal/message
input and output soon.

1 files changed, 197 insertions, 0 deletions

diff --git a/src/stdio-commands.c b/src/stdio-commands.c
new file mode 100644
index 0000000..263425c
--- /dev/null
+++ b/src/stdio-commands.c
@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2012-2025 Robin Haberkorn
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <glib.h>
+
+#include "sciteco.h"
+#include "parser.h"
+#include "error.h"
+#include "expressions.h"
+#include "interface.h"
+#include "cmdline.h"
+#include "core-commands.h"
+#include "stdio-commands.h"
+
+/**
+ * Print number from stack in the given radix.
+ *
+ * It must be popped manually, so we can call it multiple times
+ * on the same number.
+ */
+static gboolean
+teco_print(guint radix, GError **error)
+{
+	if (!teco_expressions_eval(FALSE, error))
+		return FALSE;
+	if (!teco_expressions_args()) {
+		teco_error_argexpected_set(error, "=");
+		return FALSE;
+	}
+	/*
+	 * FIXME: There should be a raw output function,
+	 * also to allow output without trailing LF.
+	 * Perhaps repurpose teco_expressions_format().
+	 */
+	const gchar *fmt = "%" TECO_INT_MODIFIER "d";
+	switch (radix) {
+	case 8:  fmt = "%" TECO_INT_MODIFIER "o"; break;
+	case 16: fmt = "%" TECO_INT_MODIFIER "X"; break;
+	}
+	teco_interface_msg(TECO_MSG_USER, fmt, teco_expressions_peek_num(0));
+	return TRUE;
+}
+
+/*$ "=" "==" "===" print
+ * <n>= -- Print integer as message
+ * <n>==
+ * <n>===
+ *
+ * Shows integer <n> as a message in the message line and/or
+ * on the console.
+ * One \(lq=\(rq formats the integer as a signed decimal number,
+ * \(lq==\(rq formats as an unsigned octal number and
+ * \(lq===\(rq as an unsigned hexadecimal number.
+ * It is logged with the user-message severity.
+ * The command fails if <n> is not given.
+ *
+ * A noteworthy quirk is that \(lq==\(rq and \(lq===\(rq
+ * will print 2 or 3 numbers in succession when executed
+ * from interactive mode at the end of the command line
+ * in order to guarantee immediate feedback.
+ *
+ * If you want to print multiple values from the stack,
+ * you have to put the \(lq=\(rq into a pass-through loop
+ * or separate the commands with
+ * whitespace (e.g. \(lq^Y= =\(rq).
+ */
+/*
+ * In order to imitate TECO-11 closely, we apply the lookahead
+ * strategy -- `=` and `==` are not executed immediately but only
+ * when a non-`=` character is parsed (cf. `$$` and `^C^C`).
+ * However, this would be very annoying during interactive
+ * execution, therefore we still print the number immediately
+ * and perhaps multiple times:
+ * Typing `===` prints the number first in decimal,
+ * then octal and finally in hexadecimal.
+ * This won't happen e.g. in a loop that is closed on the command-line.
+ *
+ * FIXME: Support colon-modifier to suppress line-break on console.
+ */
+TECO_DECLARE_STATE(teco_state_print_octal);
+
+static gboolean
+teco_state_print_decimal_initial(teco_machine_main_t *ctx, GError **error)
+{
+	if (ctx->flags.mode > TECO_MODE_NORMAL || !teco_cmdline_is_executing(ctx))
+		return TRUE;
+	/*
+	 * Interactive invocation:
+	 * don't yet pop number as we may have to print it repeatedly
+	 */
+	return teco_print(10, error);
+}
+
+static teco_state_t *
+teco_state_print_decimal_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
+{
+	if (chr == '=')
+		return &teco_state_print_octal;
+
+	if (ctx->flags.mode == TECO_MODE_NORMAL) {
+		if (!teco_cmdline_is_executing(ctx) && !teco_print(10, error))
+			return NULL;
+		teco_expressions_pop_num(0);
+	}
+	return teco_state_start_input(ctx, chr, error);
+}
+
+/*
+ * Due to the deferred nature of `=`,
+ * it is valid to end in this state as well.
+ */
+static gboolean
+teco_state_print_decimal_end_of_macro(teco_machine_main_t *ctx, GError **error)
+{
+	if (teco_cmdline_is_executing(ctx) || ctx->flags.mode > TECO_MODE_NORMAL)
+		return TRUE;
+	if (!teco_print(10, error))
+		return FALSE;
+	teco_expressions_pop_num(0);
+	return TRUE;
+}
+
+TECO_DEFINE_STATE_START(teco_state_print_decimal,
+	.initial_cb = (teco_state_initial_cb_t)teco_state_print_decimal_initial,
+	.end_of_macro_cb = (teco_state_end_of_macro_cb_t)
+	                   teco_state_print_decimal_end_of_macro
+);
+
+static gboolean
+teco_state_print_octal_initial(teco_machine_main_t *ctx, GError **error)
+{
+	if (ctx->flags.mode > TECO_MODE_NORMAL || !teco_cmdline_is_executing(ctx))
+		return TRUE;
+	/*
+	 * Interactive invocation:
+	 * don't yet pop number as we may have to print it repeatedly
+	 */
+	return teco_print(8, error);
+}
+
+static teco_state_t *
+teco_state_print_octal_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
+{
+	if (chr == '=') {
+		if (ctx->flags.mode == TECO_MODE_NORMAL) {
+			if (!teco_print(16, error))
+				return NULL;
+			teco_expressions_pop_num(0);
+		}
+		return &teco_state_start;
+	}
+
+	if (ctx->flags.mode == TECO_MODE_NORMAL) {
+		if (!teco_cmdline_is_executing(ctx) && !teco_print(8, error))
+			return NULL;
+		teco_expressions_pop_num(0);
+	}
+	return teco_state_start_input(ctx, chr, error);
+}
+
+/*
+ * Due to the deferred nature of `==`,
+ * it is valid to end in this state as well.
+ */
+static gboolean
+teco_state_print_octal_end_of_macro(teco_machine_main_t *ctx, GError **error)
+{
+	if (teco_cmdline_is_executing(ctx) || ctx->flags.mode > TECO_MODE_NORMAL)
+		return TRUE;
+	if (!teco_print(8, error))
+		return FALSE;
+	teco_expressions_pop_num(0);
+	return TRUE;
+}
+
+TECO_DEFINE_STATE_START(teco_state_print_octal,
+	.initial_cb = (teco_state_initial_cb_t)teco_state_print_octal_initial,
+	.end_of_macro_cb = (teco_state_end_of_macro_cb_t)
+	                   teco_state_print_octal_end_of_macro
+);