make sqlite.DB public; make string.left/right private

vlib/builtin/string.v

@@ -470,7 +470,7 @@ pub fn (s string) split_into_lines() []string {
 }
 
 // 'hello'.left(2) => 'he'
-pub fn (s string) left(n int) string {
+fn (s string) left(n int) string {
 	if n >= s.len {
 		return s
 	}
@@ -478,7 +478,7 @@ pub fn (s string) left(n int) string {
 }
 
 // 'hello'.right(2) => 'llo'
-pub fn (s string) right(n int) string {
+fn (s string) right(n int) string {
 	if n >= s.len {
 		return ''
 	}

vlib/compiler/fn.v

@@ -669,7 +669,7 @@ fn (p mut Parser) check_unused_and_mut_vars() {
 			p.production_error_with_token_index('`$var.name` declared and not used', var.token_idx)
 		}
 		if !var.is_changed && var.is_mut && !p.pref.is_repl && !p.pref.translated && var.typ != 'T*' && p.mod != 'ui' && var.typ != 'App*' {
-			//p.warn_or_error('`$var.name` is declared as mutable, but it was never changed')
+			p.warn_or_error('`$var.name` is declared as mutable, but it was never changed')
 		}
 	}
 }

vlib/sqlite/sqlite.v

@@ -8,12 +8,12 @@ module sqlite
 struct C.sqlite3
 struct C.sqlite3_stmt
 
-struct DB {
+pub struct DB {
 mut:
 	conn &C.sqlite3
 }
 
-struct Row {
+pub struct Row {
 pub mut:
 	vals []string
 }
@@ -39,6 +39,7 @@ fn C.sqlite3_open()
 fn C.sqlite3_step() int
 fn C.sqlite3_prepare_v2()
 fn C.sqlite3_finalize()
+fn C.sqlite3_column_count(voidptr) int
 
 pub fn (db DB) q_string(query string) string {
 	stmt := &C.sqlite3_stmt(0)
@@ -49,7 +50,6 @@ pub fn (db DB) q_string(query string) string {
 	return res
 }
 
-fn C.sqlite3_column_count(voidptr) int
 
 pub fn (db DB) exec(query string) []Row {
 	stmt := &C.sqlite3_stmt(0)