Add index ranges

Builtin 'set' now can set variable index ranges:
  set test[1..3] a b c #works
  set test[-1..-3] a b c #works if variable have enough elements
  set test[2..-2]  a b c #works
  set test[1..3 -1..-2] a b c b b #works

Expand now can parse index ranges. But not handle for now.

TODO:
  * Add variable substitution index ranges: echo $PATH[-1..1]
  * Add command substitution index range: echo (seq 10)[-1..-4]
  * Add process substitution indexes and ranges: echo %vim[-1]

1 files changed, 26 insertions, 4 deletions

diff --git a/builtin_set.cpp b/builtin_set.cpp
index c1bb65cc..11fe2ab9 100644
--- a/builtin_set.cpp
+++ b/builtin_set.cpp
@@ -236,11 +236,33 @@ static int parse_index( std::vector<long> &indexes,
 			l_ind = var_count+l_ind+1;
 		}
 		
-		indexes.push_back( l_ind );
 		src = end;
-		count++;
-		while (iswspace(*src)) src++;
-	}
+        if ( *src==L'.' && *(src+1)==L'.' ){
+            src+=2;
+            long l_ind2 = wcstol( src, &end, 10 );
+            if( end==src || errno )
+            {
+                return 1;
+            }
+            src = end;
+
+            if( l_ind2 < 0 )
+            {
+                l_ind2 = var_count+l_ind2+1;
+            }
+            int direction = l_ind2<l_ind ? -1 : 1 ;
+            for (long jjj = l_ind; jjj*direction <= l_ind2*direction; jjj+=direction) {
+                // debug(0, L"Expand range [set]: %i\n", jjj); 
+                indexes.push_back( jjj );
+                count++;
+            }
+        }
+        else {
+            indexes.push_back( l_ind );
+            count++;
+        }
+        while (iswspace(*src)) src++;
+    }
 
 	return count;
 }