format-table: add an API for getting the cell at a specific row/column

src/shared/format-table.c

@@ -1370,3 +1370,18 @@ int table_set_reverse(Table *t, size_t column, bool b) {
         t->reverse_map[column] = b;
         return 0;
 }
+
+TableCell *table_get_cell(Table *t, size_t row, size_t column) {
+        size_t i;
+
+        assert(t);
+
+        if (column >= t->n_columns)
+                return NULL;
+
+        i = row * t->n_columns + column;
+        if (i >= t->n_cells)
+                return NULL;
+
+        return TABLE_INDEX_TO_CELL(i);
+}

src/shared/format-table.h

@@ -66,3 +66,5 @@ static inline TableCell* TABLE_HEADER_CELL(size_t i) {
 
 size_t table_get_rows(Table *t);
 size_t table_get_columns(Table *t);
+
+TableCell *table_get_cell(Table *t, size_t row, size_t column);