autocomplete.d

   1 /* Invisible Vector Library
   2  * coded by Ketmar // Invisible Vector <ketmar@ketmar.no-ip.org>
   3  * Understanding is not required. Only obedience.
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 module iv.autocomplete is aliced;
  19
  20 import iv.alice;
  21
  22
  23 /**
  24  * Build list of suitable autocompletions.
  25  *
  26  * Params:
  27  *  cmd = user-given command prefix
  28  *  cmdlist = list of all available commands
  29  *
  30  * Returns:
  31  *  null = no matches (empty array)
  32  *  array with one item: exactly one match
  33  *  array with more that one item = [0] is max prefix, then list of autocompletes
  34  *
  35  * Throws:
  36  *  Out of memory exception
  37  */
  38 string[] autocomplete (string cmd, string[] cmdlist...) @trusted nothrow {
  39   if (cmdlist.length == 0) return [cmd];
  40   string found; // autoinit
  41   usize foundlen, pfxcount; // autoinit
  42   // ÐÅÒ×ÙÊ ÐÒÏÈÏÄ: ÓÞÉÔÁÅÍ ÐÒÅÆÉËÓÙ, ÚÁÐÏÍÉÎÁÅÍ ËÏÍÁÎÄÕ Ó ÓÁÍÙÍ ÄÌÉÎÎÙÍ ÐÒÅÆÉËÓÏÍ
  43   foreach (immutable s; cmdlist) {
  44     if (cmd.length <= s.length) {
  45       usize pos = cmd.length;
  46       foreach (immutable idx; 0..cmd.length) if (cmd[idx] != s[idx]) { pos = idx; break; }
  47       if (pos == cmd.length) {
  48         if (s.length > found.length) found = s;
  49         ++pfxcount;
  50       }
  51     }
  52   }
  53   if (pfxcount == 0) return null; // ÎÅ ÎÁÛÌÉ ×ÏÏÂÝÅ ÎÉÈÅÒÁ, ×ÁÌÉÍ ÏÔÓÀÄÁ, ÐÁÃÁÎÙ!
  54   if (pfxcount == 1) return [found]; // ÅÓÔØ ÔÏÌØËÏ ÏÄÉÎ, ÕÎÏÓÉÔÅ
  55   // ÎÁÛÌÉ ÄÏÈÅÒÁ, ÜÔÏ ÐÒÉÓËÏÒÂÎÏ
  56   // ÉÝÅÍ ÓÁÍÙÊ ÄÌÉÎÎÙÊ ÐÒÅÆÉËÓ ÉÚ ×ÏÚÍÏÖÎÙÈ, ÚÁÏÄÎÏ ÓÏÂÉÒÁÅÍ ×Ó£, ÞÔÏ ÍÏÖÎÏ
  57   string[] res = new string[pfxcount+1]; // ÓÀÄÁ ÓÌÏÖÉÍ ×Ó£ ÐÏÄÈÏÄÑÝÅÅ; ÍÙ ÔÏÞÎÏ ÚÎÁÅÍ, ÓËÏÌØËÏ ÉÈ ÂÕÄÅÔ
  58   usize respos = 1; // res[0] -- ÓÁÍÙÊ ÄÌÉÎÎÙÊ ÐÒÅÆÉËÓ, ÎÁÞÎ£Í Ó [1]
  59   usize slen = cmd.length; // ÔÏÞÎÏ ÎÅ ÂÏÌØÛÅ found.length
  60   foreach (immutable s; cmdlist) {
  61     if (s.length >= slen) {
  62       usize pos = slen;
  63       foreach (immutable idx; 0..slen) if (found[idx] != s[idx]) { pos = idx; break; }
  64       if (pos == slen) {
  65         // ÎÁÛÅ, ÚÁÐÏÍÉÎÁÅÍ É ÐÒÁ×ÉÍ ÐÒÅÆÉËÓ
  66         res[respos++] = s;
  67         // ÏÂÒÅÚÁÅÍ ÐÏ ÍÉÎÉÍÕÍÕ, ÎÏ ÎÅ ÍÅÎØÛÅ, ÞÅÍ ÎÁÄÏ
  68         for (; pos < found.length && pos < s.length; ++pos) if (found[pos] != s[pos]) break;
  69         if (pos < found.length) {
  70           found = found[0..pos];
  71           if (slen > pos) slen = pos;
  72         }
  73       }
  74     }
  75   }
  76   // ÐÅÒ×ÙÍ ÜÌÅÍÅÎÔÏÍ ×ÓÔÁ×ÉÍ ÍÁËÓÉÍÁÌØÎÙÊ ÐÒÅÆÉËÓ
  77   res[0] = found;
  78   // ×Ó£
  79   return res;
  80 }
  81
  82
  83 unittest {
  84   import std.stdio;
  85   {
  86     static immutable string[3] clist0 = ["aaz", "aabed", "aand"];
  87     //writeln("--------");
  88     assert(autocomplete("", clist0) == ["aa", "aaz", "aabed", "aand"]);
  89     assert(autocomplete("a", clist0) == ["aa", "aaz", "aabed", "aand"]);
  90     assert(autocomplete("aa", clist0) == ["aa", "aaz", "aabed", "aand"]);
  91     assert(autocomplete("aab", clist0) == ["aabed"]);
  92   }
  93   {
  94     static immutable string[3] clist1 = ["az", "abed", "and"];
  95     //writeln("--------");
  96     assert(autocomplete("", clist1) == ["a", "az", "abed", "and"]);
  97     assert(autocomplete("a", clist1) == ["a", "az", "abed", "and"]);
  98     assert(autocomplete("aa", clist1) == []);
  99     assert(autocomplete("aab", clist1) == []);
 100   }
 101 }