/* * call-seq: * array.transpose -> an_array * * Assumes that <i>self</i> is an array of arrays and transposes the * rows and columns. * * a = [[1,2], [3,4], [5,6]] * a.transpose #=> [[1, 3, 5], [2, 4, 6]] */ static VALUE rb_ary_transpose(ary) VALUE ary; { long elen = -1, alen, i, j; VALUE tmp, result = 0; alen = RARRAY(ary)->len; if (alen == 0) return rb_ary_dup(ary); for (i=0; i<alen; i++) { tmp = to_ary(rb_ary_elt(ary, i)); if (elen < 0) { /* first element */ elen = RARRAY(tmp)->len; result = rb_ary_new2(elen); for (j=0; j<elen; j++) { rb_ary_store(result, j, rb_ary_new2(alen)); } } else if (elen != RARRAY(tmp)->len) { rb_raise(rb_eIndexError, "element size differs (%d should be %d)", RARRAY(tmp)->len, elen); } for (j=0; j<elen; j++) { rb_ary_store(rb_ary_elt(result, j), i, rb_ary_elt(tmp, j)); } } return result; }