vi: improvements to range selection

Rewrite find_range(), pushing quite a bit of code from do_cmd()
down into it.

- The commands 'y', 'd', 'c', '<' and '>' can be given twice to
  specify a whole-line range.  BusyBox vi actually accepted any
  second character from that group, e.g. 'dc' or '<y', with the
  latter being accepted even if yank was disabled.  Require the
  two characters to match.

- '<' and '>' commands followed by ESC incorrectly issued an alert.

- Allow search commands and a marker (specified as "y'a", for example)
  to define a range for those operators that support it.

function                                             old     new   delta
find_range                                           518     707    +189
.rodata                                           105119  105133     +14
get_motion_char                                       68       -     -68
do_cmd                                              4860    4695    -165
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 2/1 up/down: 203/-233)          Total: -30 bytes

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

1 files changed, 42 insertions, 41 deletions

diff --git a/editors/vi.c b/editors/vi.c
index 5dc14f1ba..9a17f6527 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -3079,22 +3079,38 @@ static int at_eof(const char *s)
         return ((s == end - 2 && s[1] == '\n') || s == end - 1);
 }
 
-static int find_range(char **start, char **stop, char c)
+static int find_range(char **start, char **stop, int cmd)
 {
         char *save_dot, *p, *q, *t;
         int buftype = -1;
+        int c;
 
         save_dot = dot;
         p = q = dot;
 
-        if (strchr("cdy><", c)) {
+#if ENABLE_FEATURE_VI_YANKMARK
+        if (cmd == 'Y') {
+                c = 'y';
+        } else
+#endif
+        {
+                c = get_motion_char();
+        }
+
+#if ENABLE_FEATURE_VI_YANKMARK
+        if ((cmd == 'Y' || cmd == c) && strchr("cdy><", c)) {
+#else
+        if (cmd == c && strchr("cd><", c)) {
+#endif
                 // these cmds operate on whole lines
                 buftype = WHOLE;
                 if (--cmdcnt > 0)
                         do_cmd('j');
-        } else if (strchr("^%$0bBeEfFtTh|{}\b\177", c)) {
-                // These cmds operate on char positions
-                buftype = PARTIAL;
+        } else if (strchr("^%$0bBeEfFtThnN/?|{}\b\177", c)) {
+                // Most operate on char positions within a line.  Of those that
+                // don't '%' needs no special treatment, search commands are
+                // marked as MULTI and  "{}" are handled below.
+                buftype = strchr("nN/?", c) ? MULTI : PARTIAL;
                 do_cmd(c);              // execute movement cmd
                 if (p == dot)   // no movement is an error
                         buftype = -1;
@@ -3104,7 +3120,16 @@ static int find_range(char **start, char **stop, char c)
                 // step back one char, but not if we're at end of file
                 if (dot > p && !at_eof(dot))
                         dot--;
-        } else if (strchr("GHL+-jk\r\n", c)) {
+                t = dot;
+                // don't include trailing WS as part of word
+                while (dot > p && isspace(*dot)) {
+                        if (*dot-- == '\n')
+                                t = dot;
+                }
+                // for non-change operations WS after NL is not part of word
+                if (cmd != 'c' && dot != p && *dot != '\n')
+                        dot = t;
+        } else if (strchr("GHL+-jk'\r\n", c)) {
                 // these operate on whole lines
                 buftype = WHOLE;
                 do_cmd(c);              // execute movement cmd
@@ -3119,8 +3144,11 @@ static int find_range(char **start, char **stop, char c)
                         dot--;
         }
 
-        if (buftype == -1)
+        if (buftype == -1) {
+                if (c != 27)
+                        indicate_error();
                 return buftype;
+        }
 
         q = dot;
         if (q < p) {
@@ -3131,7 +3159,7 @@ static int find_range(char **start, char **stop, char c)
 
         // movements which don't include end of range
         if (q > p) {
-                if (strchr("^0bBFTh|\b\177", c)) {
+                if (strchr("^0bBFThnN/?|\b\177", c)) {
                         q--;
                 } else if (strchr("{}", c)) {
                         buftype = (p == begin_line(p) && (*q == '\n' || at_eof(q))) ?
@@ -3144,7 +3172,7 @@ static int find_range(char **start, char **stop, char c)
                 }
         }
 
-        if (buftype == WHOLE) {
+        if (buftype == WHOLE || cmd == '<' || cmd == '>') {
                 p = begin_line(p);
                 q = end_line(q);
         }
@@ -3582,14 +3610,9 @@ static void do_cmd(int c)
         case '<':                       // <- Left  shift something
         case '>':                       // >- Right shift something
                 cnt = count_lines(text, dot);   // remember what line we are on
-                c1 = get_motion_char(); // get the type of thing to operate on
-                if (find_range(&p, &q, c1) == -1) {
-                        indicate_error();
+                if (find_range(&p, &q, c) == -1)
                         goto dc6;
-                }
                 yank_delete(p, q, WHOLE, YANKONLY, NO_UNDO);    // save copy before change
-                p = begin_line(p);
-                q = end_line(q);
                 i = count_lines(p, q);  // # of lines we are shifting
                 for ( ; i > 0; i--, p = next_line(p)) {
                         if (c == '<') {
@@ -3820,39 +3843,17 @@ static void do_cmd(int c)
         case 'Y':                       // Y- Yank a line
 #endif
         {
+                int yf = YANKDEL;       // assume either "c" or "d"
+                int buftype;
 #if ENABLE_FEATURE_VI_YANKMARK
                 char *savereg = reg[YDreg];
-#endif
-                int yf, buftype = 0;
-                yf = YANKDEL;   // assume either "c" or "d"
-#if ENABLE_FEATURE_VI_YANKMARK
                 if (c == 'y' || c == 'Y')
                         yf = YANKONLY;
 #endif
-                c1 = 'y';
-                if (c != 'Y') {
-                        c1 = get_motion_char(); // get the type of thing to operate on
-                        if (c1 == 27)   // ESC- user changed mind and wants out
-                                goto dc6;
-                }
                 // determine range, and whether it spans lines
-                buftype = find_range(&p, &q, c1);
-                place_cursor(0, 0);
-                if (buftype == -1) { // invalid range
-                        indicate_error();
+                buftype = find_range(&p, &q, c);
+                if (buftype == -1)      // invalid range
                         goto dc6;
-                }
-                if (c1 == 'w' || c1 == 'W') {
-                        char *q0 = q;
-                        // don't include trailing WS as part of word
-                        while (q > p && isspace(*q)) {
-                                if (*q-- == '\n')
-                                        q0 = q;
-                        }
-                        // for non-change operations WS after NL is not part of word
-                        if (c != 'c' && q != p && *q != '\n')
-                                q = q0;
-                }
                 dot = yank_delete(p, q, buftype, yf, ALLOW_UNDO);       // delete word
                 if (buftype == WHOLE) {
                         if (c == 'c') {