From e030a2ca08d92eb431e9b8e494c63affeeb8c0e1 Mon Sep 17 00:00:00 2001
From: Craig Barnes <craigbarnes@protonmail.com>
Date: Wed, 9 Jun 2021 09:51:48 +0100
Subject: [PATCH] terminal: add 'charset_designator' enum to make code more
 self-documenting

This commit also renames the term_set_single_shift_ascii_printer()
function to term_single_shift(), since the former is overly verbose
and not really even accurate.
---
 terminal.c | 14 +++++++-------
 terminal.h |  7 ++++---
 vt.c       | 16 ++++++++--------
 3 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/terminal.c b/terminal.c
index 5ba7b854..ddc93cad 100644
--- a/terminal.c
+++ b/terminal.c
@@ -1606,11 +1606,11 @@ term_reset(struct terminal *term, bool hard)
     term->bell_action_enabled = true;
     term->mouse_tracking = MOUSE_NONE;
     term->mouse_reporting = MOUSE_NORMAL;
-    term->charsets.selected = 0;
-    term->charsets.set[0] = CHARSET_ASCII;
-    term->charsets.set[1] = CHARSET_ASCII;
-    term->charsets.set[2] = CHARSET_ASCII;
-    term->charsets.set[3] = CHARSET_ASCII;
+    term->charsets.selected = G0;
+    term->charsets.set[G0] = CHARSET_ASCII;
+    term->charsets.set[G1] = CHARSET_ASCII;
+    term->charsets.set[G2] = CHARSET_ASCII;
+    term->charsets.set[G3] = CHARSET_ASCII;
     term->saved_charsets = term->charsets;
     tll_free_and_free(term->window_title_stack, free);
     term_set_window_title(term, term->conf->title);
@@ -2869,10 +2869,10 @@ term_update_ascii_printer(struct terminal *term)
 }
 
 void
-term_set_single_shift_ascii_printer(struct terminal *term, int selected)
+term_single_shift(struct terminal *term, enum charset_designator idx)
 {
     term->charsets.saved = term->charsets.selected;
-    term->charsets.selected = selected;
+    term->charsets.selected = idx;
     term->ascii_printer = &ascii_printer_single_shift;
 }
 
diff --git a/terminal.h b/terminal.h
index a54185e2..b96621fd 100644
--- a/terminal.h
+++ b/terminal.h
@@ -189,10 +189,11 @@ enum cursor_origin { ORIGIN_ABSOLUTE, ORIGIN_RELATIVE };
 enum cursor_keys { CURSOR_KEYS_DONTCARE, CURSOR_KEYS_NORMAL, CURSOR_KEYS_APPLICATION };
 enum keypad_keys { KEYPAD_DONTCARE, KEYPAD_NUMERICAL, KEYPAD_APPLICATION };
 enum charset { CHARSET_ASCII, CHARSET_GRAPHIC };
+enum charset_designator { G0, G1, G2, G3 };
 
 struct charsets {
-    int selected;
-    int saved;
+    enum charset_designator selected;
+    enum charset_designator saved;
     enum charset set[4]; /* G0-G3 */
 };
 
@@ -606,7 +607,7 @@ bool term_shutdown(struct terminal *term);
 int term_destroy(struct terminal *term);
 
 void term_update_ascii_printer(struct terminal *term);
-void term_set_single_shift_ascii_printer(struct terminal *term, int selected);
+void term_single_shift(struct terminal *term, enum charset_designator idx);
 
 void term_reset(struct terminal *term, bool hard);
 bool term_to_slave(struct terminal *term, const void *data, size_t len);
diff --git a/vt.c b/vt.c
index 26affcd2..3bd831a8 100644
--- a/vt.c
+++ b/vt.c
@@ -196,13 +196,13 @@ action_execute(struct terminal *term, uint8_t c)
 
     case '\x0e':
         /* SO - shift out */
-        term->charsets.selected = 1; /* G1 */
+        term->charsets.selected = G1;
         term_update_ascii_printer(term);
         break;
 
     case '\x0f':
         /* SI - shift in */
-        term->charsets.selected = 0; /* G0 */
+        term->charsets.selected = G0;
         term_update_ascii_printer(term);
         break;
 
@@ -390,13 +390,13 @@ action_esc_dispatch(struct terminal *term, uint8_t final)
 
         case 'n':
             /* LS2 - Locking Shift 2 */
-            term->charsets.selected = 2; /* G2 */
+            term->charsets.selected = G2;
             term_update_ascii_printer(term);
             break;
 
         case 'o':
             /* LS3 - Locking Shift 3 */
-            term->charsets.selected = 3; /* G3 */
+            term->charsets.selected = G3;
             term_update_ascii_printer(term);
             break;
 
@@ -426,12 +426,12 @@ action_esc_dispatch(struct terminal *term, uint8_t final)
 
         case 'N':
             /* SS2 - Single Shift 2 */
-            term_set_single_shift_ascii_printer(term, 2); /* G2 */
+            term_single_shift(term, G2);
             break;
 
         case 'O':
             /* SS3 - Single Shift 3 */
-            term_set_single_shift_ascii_printer(term, 3); /* G3 */
+            term_single_shift(term, G3);
             break;
 
         case '\\':
@@ -460,7 +460,7 @@ action_esc_dispatch(struct terminal *term, uint8_t final)
         switch (final) {
         case '0': {
             size_t idx = term->vt.private - '(';
-            xassert(idx <= 3);
+            xassert(idx <= G3);
             term->charsets.set[idx] = CHARSET_GRAPHIC;
             term_update_ascii_printer(term);
             break;
@@ -468,7 +468,7 @@ action_esc_dispatch(struct terminal *term, uint8_t final)
 
         case 'B': {
             size_t idx = term->vt.private - '(';
-            xassert(idx <= 3);
+            xassert(idx <= G3);
             term->charsets.set[idx] = CHARSET_ASCII;
             term_update_ascii_printer(term);
             break;