vi: improvements to character search within line

- Use a common routine to handle all commands to search for a
  character in a line.

- When searching for the nth occurrence of a character don't move
  the cursor if fewer than n occurrences are present.

- Add support for the 'T' command, search backwards for character
  after next occurrence of given character.

function                                             old     new   delta
do_cmd                                              4861    4805     -56
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-56)             Total: -56 bytes

v2: Add parentheses to avoid searches continuing past end of line.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 39 insertions, 41 deletions

diff --git a/editors/vi.c b/editors/vi.c
index 2c724a448..ec2d64dfb 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -322,7 +322,8 @@ struct globals {
         char *screen;            // pointer to the virtual screen buffer
         int screensize;          //            and its size
         int tabstop;
-        int last_forward_char;   // last char searched for with 'f' (int because of Unicode)
+        int last_search_char;    // last char searched for (int because of Unicode)
+        smallint last_search_cmd;    // command used to invoke last char search
 #if ENABLE_FEATURE_VI_CRASHME
         char last_input_char;    // last char read from user
 #endif
@@ -439,7 +440,8 @@ struct globals {
 #define screensize              (G.screensize         )
 #define screenbegin             (G.screenbegin        )
 #define tabstop                 (G.tabstop            )
-#define last_forward_char       (G.last_forward_char  )
+#define last_search_char        (G.last_search_char   )
+#define last_search_cmd         (G.last_search_cmd    )
 #if ENABLE_FEATURE_VI_CRASHME
 #define last_input_char         (G.last_input_char    )
 #endif
@@ -1772,6 +1774,31 @@ static void dot_skip_over_ws(void)
                 dot++;
 }
 
+static void dot_to_char(int cmd)
+{
+        char *q = dot;
+        int dir = islower(cmd) ? FORWARD : BACK;
+
+        if (last_search_char == 0)
+                return;
+
+        do {
+                do {
+                        q += dir;
+                        if ((dir == FORWARD ? q > end - 1 : q < text) || *q == '\n')
+                                return;
+                } while (*q != last_search_char);
+        } while (--cmdcnt > 0);
+
+        dot = q;
+
+        // place cursor before/after char as required
+        if (cmd == 't')
+                dot_left();
+        else if (cmd == 'T')
+                dot_right();
+}
+
 static void dot_scroll(int cnt, int dir)
 {
         char *q;
@@ -3181,11 +3208,9 @@ static void do_cmd(int c)
                 //case '*':     // *-
                 //case '=':     // =-
                 //case '@':     // @-
-                //case 'F':     // F-
                 //case 'K':     // K-
                 //case 'Q':     // Q-
                 //case 'S':     // S-
-                //case 'T':     // T-
                 //case 'V':     // V-
                 //case '[':     // [-
                 //case '\\':    // \-
@@ -3379,36 +3404,16 @@ static void do_cmd(int c)
                         indicate_error();
                 break;
         case 'f':                       // f- forward to a user specified char
-                last_forward_char = get_one_char();     // get the search char
-                //
-                // dont separate these two commands. 'f' depends on ';'
-                //
-                //**** fall through to ... ';'
-        case ';':                       // ;- look at rest of line for last forward char
-                do {
-                        if (last_forward_char == 0)
-                                break;
-                        q = dot + 1;
-                        while (q < end - 1 && *q != '\n' && *q != last_forward_char) {
-                                q++;
-                        }
-                        if (*q == last_forward_char)
-                                dot = q;
-                } while (--cmdcnt > 0);
-                break;
-        case ',':           // repeat latest 'f' in opposite direction
-                if (last_forward_char == 0)
-                        break;
-                do {
-                        q = dot - 1;
-                        while (q >= text && *q != '\n' && *q != last_forward_char) {
-                                q--;
-                        }
-                        if (q >= text && *q == last_forward_char)
-                                dot = q;
-                } while (--cmdcnt > 0);
+        case 'F':                       // F- backward to a user specified char
+        case 't':                       // t- move to char prior to next x
+        case 'T':                       // T- move to char after previous x
+                last_search_char = get_one_char();      // get the search char
+                last_search_cmd = c;
+                // fall through
+        case ';':                       // ;- look at rest of line for last search char
+        case ',':           // ,- repeat latest search in opposite direction
+                dot_to_char(c != ',' ? last_search_cmd : last_search_cmd ^ 0x20);
                 break;
-
         case '-':                       // -- goto prev line
                 do {
                         dot_prev();
@@ -3854,13 +3859,6 @@ static void do_cmd(int c)
                 }
                 end_cmd_q();    // stop adding to q
                 break;
-        case 't':                       // t- move to char prior to next x
-                last_forward_char = get_one_char();
-                do_cmd(';');
-                if (*dot == last_forward_char)
-                        dot_left();
-                last_forward_char = 0;
-                break;
         case 'w':                       // w- forward a word
                 do {
                         if (isalnum(*dot) || *dot == '_') {     // we are on ALNUM
@@ -4204,7 +4202,7 @@ static void edit_file(char *fn)
         mark[26] = mark[27] = text;     // init "previous context"
 #endif
 
-        last_forward_char = '\0';
+        last_search_char = '\0';
 #if ENABLE_FEATURE_VI_CRASHME
         last_input_char = '\0';
 #endif