Completion for brace expansion (zsh 3.1.2)

[Peter Stephenson <pws@xxxxxx>]

Here's some code to allow completion of expressions being expanded by
brace expansion, something I've wanted for ages.  It was much simpler
and neater than I'd expected, which is a tribute to all the tidying up
that's been done on the completion code.  It seems to work like a
charm and I've adapted the AUTO_PARAM_KEYS code to help it along.

For example, in the zsh source directory (with AUTO_PARAM_KEYS set):

% ls mk*
mkbltnmlst.sh  mkstamp.sh
% echo mk{bl<TAB>                --->      mk{bltnmlst.sh _
% echo mk{bltnmlst.sh,st<TAB>    --->      mk{bltnmlst.sh,stamp.sh _
                     ^comma is magic, space deleted
% echo mk{bltnmlst.sh,stamp.sh}
                              ^ likewise with closing brace

COMPLETE_IN_WORD also works well (e.g. try mk{bl<TAB>}.sh and see what
happens).  The most significant limitation is that only one layer of
braces is handled.  The real problem comes when there is already a
complete brace expansion elsewhere in the string, then it becomes much
harder.

*** Doc/Zsh/options.yo.brace	Thu Jun 26 18:33:51 1997
--- Doc/Zsh/options.yo	Tue Aug 12 17:01:04 1997
***************
*** 99,105 ****
  (normally a space) automatically
  inserted, and the next character typed is one
  of those that have to come directly after the name (like `tt(})', `tt(:)',
! etc.), the character is inserted em(before) the space rather than after.
  )
  pindex(AUTO_PARAM_SLASH)
  item(tt(AUTO_PARAM_SLASH))(
--- 99,109 ----
  (normally a space) automatically
  inserted, and the next character typed is one
  of those that have to come directly after the name (like `tt(})', `tt(:)',
! etc.), the character is inserted em(before) the space rather than
! after.  Brace expansion is handled similarly, assuming
! tt(IGNORE_BRACES) is not set: if a completion was made in an
! unfinished brace expansion, then typing a comma or closing brace will
! cause it to be added before the space.
  )
  pindex(AUTO_PARAM_SLASH)
  item(tt(AUTO_PARAM_SLASH))(
*** Src/Zle/zle_misc.c.brace	Fri Jul  4 14:55:07 1997
--- Src/Zle/zle_misc.c	Tue Aug 12 16:53:26 1997
***************
*** 67,77 ****
  	if (complexpect == 2 && /*{*/ c1 == '}') {
  		cs -= ks = addedsuffix;
  		complexpect = 0;
! 	} else if (c1 == ':' || c1 == '[' || (complexpect == 2 &&
  		    (c1 == '#' || c1 == '%' || c1 == '-' ||
! 		     c1 == '?' || c1 == '+' || c1 == '=')))
  	    /* Otherwise, if the character being added needs to come    *
! 	     * immediately after the parameter name, remove the suffix. */
  	    removesuffix();
      }
      ncs = neg ? cs : cs + m * len;
--- 67,80 ----
  	if (complexpect == 2 && /*{*/ c1 == '}') {
  		cs -= ks = addedsuffix;
  		complexpect = 0;
! 	} else if ((complexpect < 3 && (c1 == ':' || c1 == '[')) ||
! 		   (complexpect == 2 &&
  		    (c1 == '#' || c1 == '%' || c1 == '-' ||
! 		     c1 == '?' || c1 == '+' || c1 == '=')) ||
! 		   (complexpect == 3 && (c1 == '}' || c1 == ',')))
  	    /* Otherwise, if the character being added needs to come    *
! 	     * immediately after the parameter name, remove the suffix. *
! 	     * We also deal with brace expansion (no '$') here.	        */
  	    removesuffix();
      }
      ncs = neg ? cs : cs + m * len;
*** Src/Zle/zle_tricky.c.brace	Tue Aug  5 09:35:40 1997
--- Src/Zle/zle_tricky.c	Tue Aug 12 16:50:26 1997
***************
*** 104,109 ****
--- 104,114 ----
  
  static int menuce;
  
+ /* This is used as a flag from get_comp_string() that we are doing *
+  * completion inside a brace expansion.                          */
+ 
+ static int complinbrace;
+ 
  /* The list of matches.  fmatches contains the matches we first ignore *
   * because of fignore.                                                 */
  
***************
*** 847,852 ****
--- 852,858 ----
      int t0, tt0, i, j, k, cp, rd, sl, ocs;
      char *s = NULL, *linptr, *tmp, *p, *tt = NULL;
  
+     complinbrace = 0;
      /* This global flag is used to signal the lexer code if it should *
       * expand aliases or not.                                         */
      noaliases = isset(COMPLETEALIASES);
***************
*** 1120,1125 ****
--- 1126,1199 ----
  		}
  		chuck(p--);
  	    }
+ 
+ 	if (!isset(IGNOREBRACES)) {
+ 	    /* Try and deal with foo{xxx etc.; only simple cases
+ 	     * (only one inbrace, completion after inbrace and before outbrace
+ 	     * if present).
+ 	     */
+ 	    int myoffs = isset(COMPLETEINWORD) ? offs : strlen(s);
+ 	    tt = NULL;
+ 	    /* First check the conditions mentioned above
+ 	     * and locate opening brace
+ 	     */
+ 	    for (i = 0, p = s; *p; p++, i++) {
+ 		/* careful, ${... is not a brace expansion...
+ 		 * in fact, if it's got a substitution in it's too
+ 		 * hard for us anyway.  sorry.
+ 		 */
+ 		if (*p == String || *p == Qstring) {
+ 		    tt = NULL;
+ 		    break;
+ 		} else if (*p == Inbrace) {
+ 		    if (tt) {
+ 			/* too many inbraces */
+ 			tt = NULL;
+ 			break;
+ 		    }
+ 		    tt = p;
+ 		} else if (*p == Outbrace && i < myoffs) {
+ 		    /* outbrace is before cursor pos, so nothing to complete */
+ 		    tt = NULL;
+ 		    break;
+ 		}
+ 	    }
+ 
+ 	    if (tt && tt < s + myoffs) {
+ 		/* Braces are go:  delete opening brace */
+ 		char *com = NULL;
+ 		chuck(tt);
+ 		offs--;
+ 		myoffs--;
+ 
+ 		/* Look for text up to comma before cursor and delete it */
+ 		for (i = tt - s, p = tt; *p && i < myoffs; p++, i++)
+ 		    if (*p == Comma)
+ 			com = p;
+ 		if (com) {
+ 		    i = com - tt + 1;
+ 		    while (i--)
+ 			chuck(tt), offs--, myoffs--;
+ 		}
+ 
+ 		/* Look for text between subsequent comma
+ 		 * and closing brace or end of string and delete it
+ 		 */
+ 		for (p = s + myoffs; *p && *p != Outbrace; p++)
+ 		    if (*p == Comma) {
+ 			while (*p && *p != Outbrace)
+ 			    chuck(p);
+ 			break;
+ 		    }
+ 		if (*p == Outbrace)
+ 		    chuck(p);
+ 		else {
+ 		    /* we are still waiting for an outbrace and maybe commas */
+ 		    complinbrace = 1;
+ 		}
+ 	    }
+ 	}
+ 
      } LASTALLOC;
      lexrestore();
  
***************
*** 2335,2340 ****
--- 2409,2416 ----
  	    cc_dummy.mask = CC_PARAMS | CC_ENVVARS;
  	} else
  	    complexpect = 0;
+     } else if (complinbrace) {
+ 	complexpect = 3;
      }
      ooffs = offs;
      /* If we have to ignore the word, do that. */

-- 
Peter Stephenson <pws@xxxxxx>       Tel: +49 33762 77366
WWW:  http://www.ifh.de/~pws/       Fax: +49 33762 77413
Deutsches Elektronen-Synchrotron --- Institut fuer Hochenergiephysik Zeuthen
DESY-IfH, Platanenallee 6, 15738 Zeuthen, Germany.