ex_getln: refactor command line mode to use the state_enter loop

Split `getcmdline()` into command_line_{enter,check,execute}`

src/nvim/ex_getln.c

@@ -160,32 +160,7 @@ static int hislen = 0;                  /* actual length of history tables */
 static int cmd_hkmap = 0;       /* Hebrew mapping during command line */
 
 static int cmd_fkmap = 0;       /* Farsi mapping during command line */
-
+static uint8_t *command_line_enter(int firstc, long count, int indent)
-/*
- * getcmdline() - accept a command line starting with firstc.
- *
- * firstc == ':'	    get ":" command line.
- * firstc == '/' or '?'	    get search pattern
- * firstc == '='	    get expression
- * firstc == '@'	    get text for input() function
- * firstc == '>'	    get text for debug mode
- * firstc == NUL	    get text for :insert command
- * firstc == -1		    like NUL, and break on CTRL-C
- *
- * The line is collected in ccline.cmdbuff, which is reallocated to fit the
- * command line.
- *
- * Careful: getcmdline() can be called recursively!
- *
- * Return pointer to allocated string if there is a commandline, NULL
- * otherwise.
- */
-char_u *
-getcmdline (
-    int firstc,
-    long count,              // only used for incremental search
-    int indent               // indent for inside conditionals
-)
 {
   CommandLineState state, *s = &state;
   memset(s, 0, sizeof(CommandLineState));
@@ -298,27 +273,100 @@ getcmdline (
 
   did_emsg = false;
   got_int = false;
+  s->state.check = command_line_check;
+  s->state.execute = command_line_execute;
+  state_enter(&s->state);
 
-  // Collect the command string, handling editing keys.
+  cmdmsg_rl = false;
-  for (;;) {
+
+  cmd_fkmap = 0;
+
+  ExpandCleanup(&s->xpc);
+  ccline.xpc = NULL;
+
+  if (s->did_incsearch) {
+    curwin->w_cursor = s->old_cursor;
+    curwin->w_curswant = s->old_curswant;
+    curwin->w_leftcol = s->old_leftcol;
+    curwin->w_topline = s->old_topline;
+    curwin->w_topfill = s->old_topfill;
+    curwin->w_botline = s->old_botline;
+    highlight_match = false;
+    validate_cursor();          // needed for TAB
+    redraw_later(SOME_VALID);
+  }
+
+  if (ccline.cmdbuff != NULL) {
+    // Put line in history buffer (":" and "=" only when it was typed).
+    if (ccline.cmdlen && s->firstc != NUL
+        && (s->some_key_typed || s->histype == HIST_SEARCH)) {
+      add_to_history(s->histype, ccline.cmdbuff, true,
+          s->histype == HIST_SEARCH ? s->firstc : NUL);
+      if (s->firstc == ':') {
+        xfree(new_last_cmdline);
+        new_last_cmdline = vim_strsave(ccline.cmdbuff);
+      }
+    }
+
+    if (s->gotesc) {           // abandon command line
+      xfree(ccline.cmdbuff);
+      ccline.cmdbuff = NULL;
+      if (msg_scrolled == 0) {
+        compute_cmdrow();
+      }
+      MSG("");
+      redraw_cmdline = true;
+    }
+  }
+
+  // If the screen was shifted up, redraw the whole screen (later).
+  // If the line is too long, clear it, so ruler and shown command do
+  // not get printed in the middle of it.
+  msg_check();
+  msg_scroll = s->save_msg_scroll;
+  redir_off = false;
+
+  // When the command line was typed, no need for a wait-return prompt.
+  if (s->some_key_typed) {
+    need_wait_return = false;
+  }
+
+  State = s->save_State;
+  setmouse();
+  ui_cursor_shape();            // may show different cursor shape
+
+  {
+    char_u *p = ccline.cmdbuff;
+
+    // Make ccline empty, getcmdline() may try to use it.
+    ccline.cmdbuff = NULL;
+    return p;
+  }
+}
+
+static int command_line_check(VimState *state)
+{
   redir_off = true;        // Don't redirect the typed command.
   // Repeated, because a ":redir" inside
   // completion may switch it on.
   quit_more = false;       // reset after CTRL-D which had a more-prompt
 
   cursorcmd();             // set the cursor on the right spot
+  return 1;
+}
 
-    // Get a character.  Ignore K_IGNORE, it should not do anything, such
+static int command_line_execute(VimState *state, int key)
-    // as stop completion.
+{
-    input_enable_events();
+  if (key == K_IGNORE || key == K_PASTE) {
-    do {
+    return -1;  // get another key
-      s->c = safe_vgetc();
+  }
-    } while (s->c == K_IGNORE || s->c == K_PASTE);
+
-    input_disable_events();
+  CommandLineState *s = (CommandLineState *)state;
+  s->c = key;
 
   if (s->c == K_EVENT) {
     queue_process_events(loop.events);
-      continue;
+    return 1;
   }
 
   if (KeyTyped) {
@@ -645,7 +693,7 @@ getcmdline (
       }
       s->gotesc = true;        // will free ccline.cmdbuff after putting it
                                // in history
-        goto returncmd;          // back to Normal mode
+      return 0;                // back to Normal mode
     }
   }
 
@@ -684,7 +732,7 @@ getcmdline (
         ui_cursor_goto(msg_row, 0);
         ui_flush();
       }
-        break;
+      return 0;
     }
   }
 
@@ -894,7 +942,7 @@ getcmdline (
         msg_putchar(' ');                             // delete ':'
       }
       redraw_cmdline = true;
-        goto returncmd;                         // back to cmd mode
+      return 0;                           // back to cmd mode
     }
     goto cmdline_changed;
 
@@ -962,7 +1010,7 @@ getcmdline (
 
     s->gotesc = true;                 // will free ccline.cmdbuff after
                                       // putting it in history
-      goto returncmd;                   // back to cmd mode
+    return 0;                         // back to cmd mode
 
   case Ctrl_R:                        // insert register
     putcmdline('"', true);
@@ -999,7 +1047,7 @@ getcmdline (
       if (aborting()) {
         s->gotesc = true;              // will free ccline.cmdbuff after
                                        // putting it in history
-          goto returncmd;                // back to cmd mode
+        return 0;                      // back to cmd mode
       }
       KeyTyped = false;                // Don't do p_wc completion.
       if (new_cmdpos >= 0) {
@@ -1020,7 +1068,7 @@ getcmdline (
     }
 
     redrawcmd();
-      continue;                 // don't do incremental search now
+    return 1;                 // don't do incremental search now
 
   case K_RIGHT:
   case K_S_RIGHT:
@@ -1439,7 +1487,7 @@ getcmdline (
   // (Sorry for the goto's, I know it is ugly).
 cmdline_not_changed:
   if (!s->incsearch_postponed) {
-      continue;
+    return 1;
   }
 
 cmdline_changed:
@@ -1451,7 +1499,7 @@ cmdline_changed:
     // if there is a character waiting, search and redraw later
     if (char_avail()) {
       s->incsearch_postponed = true;
-        continue;
+      return 1;
     }
     s->incsearch_postponed = false;
     curwin->w_cursor = s->old_cursor;        // start at old position
@@ -1543,75 +1591,37 @@ cmdline_changed:
       redrawcmd();
     }
   }
+
+  return 1;
 }
 
-returncmd:
+/*
-
+ * getcmdline() - accept a command line starting with firstc.
-  cmdmsg_rl = false;
+ *
-
+ * firstc == ':'	    get ":" command line.
-  cmd_fkmap = 0;
+ * firstc == '/' or '?'	    get search pattern
-
+ * firstc == '='	    get expression
-  ExpandCleanup(&s->xpc);
+ * firstc == '@'	    get text for input() function
-  ccline.xpc = NULL;
+ * firstc == '>'	    get text for debug mode
-
+ * firstc == NUL	    get text for :insert command
-  if (s->did_incsearch) {
+ * firstc == -1		    like NUL, and break on CTRL-C
-    curwin->w_cursor = s->old_cursor;
+ *
-    curwin->w_curswant = s->old_curswant;
+ * The line is collected in ccline.cmdbuff, which is reallocated to fit the
-    curwin->w_leftcol = s->old_leftcol;
+ * command line.
-    curwin->w_topline = s->old_topline;
+ *
-    curwin->w_topfill = s->old_topfill;
+ * Careful: getcmdline() can be called recursively!
-    curwin->w_botline = s->old_botline;
+ *
-    highlight_match = false;
+ * Return pointer to allocated string if there is a commandline, NULL
-    validate_cursor();          // needed for TAB
+ * otherwise.
-    redraw_later(SOME_VALID);
+ */
-  }
+char_u *
-
+getcmdline (
-  if (ccline.cmdbuff != NULL) {
+    int firstc,
-    // Put line in history buffer (":" and "=" only when it was typed).
+    long count,              // only used for incremental search
-    if (ccline.cmdlen && s->firstc != NUL
+    int indent               // indent for inside conditionals
-        && (s->some_key_typed || s->histype == HIST_SEARCH)) {
+)
-      add_to_history(s->histype, ccline.cmdbuff, true,
-          s->histype == HIST_SEARCH ? s->firstc : NUL);
-      if (s->firstc == ':') {
-        xfree(new_last_cmdline);
-        new_last_cmdline = vim_strsave(ccline.cmdbuff);
-      }
-    }
-
-    if (s->gotesc) {           // abandon command line
-      xfree(ccline.cmdbuff);
-      ccline.cmdbuff = NULL;
-      if (msg_scrolled == 0) {
-        compute_cmdrow();
-      }
-      MSG("");
-      redraw_cmdline = true;
-    }
-  }
-
-  // If the screen was shifted up, redraw the whole screen (later).
-  // If the line is too long, clear it, so ruler and shown command do
-  // not get printed in the middle of it.
-  msg_check();
-  msg_scroll = s->save_msg_scroll;
-  redir_off = false;
-
-  // When the command line was typed, no need for a wait-return prompt.
-  if (s->some_key_typed) {
-    need_wait_return = false;
-  }
-
-  State = s->save_State;
-  setmouse();
-  ui_cursor_shape();            // may show different cursor shape
-
 {
-    char_u *p = ccline.cmdbuff;
+  return command_line_enter(firstc, count, indent);
-
-    // Make ccline empty, getcmdline() may try to use it.
-    ccline.cmdbuff = NULL;
-    return p;
-  }
 }
 
 /*