'$foo()' string interpolation

vlib/compiler/fn.v

@@ -1024,13 +1024,15 @@ fn (p mut Parser) fn_call_args(f mut Fn) {
 				p.mutable_arg_error(i, arg, f)
 			}
 			if p.peek() != .name {
-				p.error('`$arg.name` is a mutable argument, you need to provide a variable to modify: `$f.name(... mut a...)`')
+				p.error('`$arg.name` is a mutable argument, you need to ' +
+					'provide a variable to modify: `${f.name}(... mut a...)`')
 			}
 			p.check(.key_mut)
 			p.fspace()
 			var_name := p.lit
 			v := p.find_var(var_name) or {
-				p.error('`$arg.name` is a mutable argument, you need to provide a variable to modify: `$f.name(... mut a...)`')
+				p.error('`$arg.name` is a mutable argument, you need to ' +
+					'provide a variable to modify: `${f.name}(... mut a...)`')
 				exit(1)
 			}
 			if !v.is_changed {
@@ -1156,7 +1158,7 @@ fn (p mut Parser) fn_call_args(f mut Fn) {
 				nr = 'third'
 			}
 			p.error('cannot use type `$typ` as type `$arg.typ` in $nr ' +
-				'argument to `$f.name()`')
+				'argument to `${f.name}()`')
 		} else {
 			saved_args << ''
 		}
@@ -1575,7 +1577,7 @@ fn (fns []Fn) contains(f Fn) bool {
 	return false
 }
 fn (p &Parser) fn_signature(f &Fn) string {
-	return '$f.typ $f.name(${f.str_args(p.table)})'
+	return '$f.typ ${f.name}(${f.str_args(p.table)})'
 }
 
 pub fn (f &Fn) v_fn_module() string {

vlib/compiler/gen_c.v

@@ -74,7 +74,7 @@ fn (p mut Parser) gen_blank_identifier_assign() {
 	p.is_var_decl = true
 	typ := p.bool_expression()
 	if typ == 'void' {
-		p.error_with_token_index('$next_expr() $err_used_as_value', p.token_idx-2)
+		p.error_with_token_index('${next_expr}() $err_used_as_value', p.token_idx-2)
 	}
 	p.is_var_decl = false
 	if !is_indexer && !is_fn_call {
@@ -417,7 +417,7 @@ fn (p mut Parser) gen_array_init(typ string, no_alloc bool, new_arr_ph int, nr_e
 	// Need to do this in the second pass, otherwise it goes to the very top of the out.c file
 	if !p.first_pass() {
 		p.cgen.set_placeholder(new_arr_ph,
-			'$new_arr($nr_elems, $nr_elems, sizeof($typ), EMPTY_ARRAY_OF_ELEMS( $typ, $nr_elems ) { ')
+			'${new_arr}($nr_elems, $nr_elems, sizeof($typ), EMPTY_ARRAY_OF_ELEMS( $typ, $nr_elems ) { ')
 	}
 }
 
@@ -494,7 +494,7 @@ fn (p mut Parser) gen_struct_init(typ string, t Type) bool {
 	else {
 		if p.tok == .not {
 			// old &User{!} ==> 0 hack
-			p.error('use `$t.name(0)` instead of `&$t.name{!}`')
+			p.error('use `${t.name}(0)` instead of `&$t.name{!}`')
 			/*
 			p.next()
 			p.gen('0')

vlib/compiler/json_gen.v

@@ -58,7 +58,7 @@ fn (p mut Parser) gen_json_for_type(typ Type) {
 	// Code gen decoder
 	dec += '
 //$t $dec_fn.name (cJSON* root) {
-Option $dec_fn.name(cJSON* root, $t* res) {
+Option ${dec_fn.name}(cJSON* root, $t* res) {
 //  $t res;
   if (!root) {
     const char *error_ptr = cJSON_GetErrorPtr();

vlib/compiler/main.v

@@ -502,12 +502,14 @@ pub fn (v mut V) generate_main() {
 			v.gen_main_start(false)
 
 			if v.pref.is_stats {
-				cgen.genln('BenchedTests bt = main__start_testing();')
+				// QQQ
+				//cgen.genln('BenchedTests bt = main__start_testing();')
 			}
 
 			for _, f in v.table.fns {
 				if f.name.starts_with('main__test_') {
-					if v.pref.is_stats { cgen.genln('BenchedTests_testing_step_start(&bt, tos3("$f.name"));') }
+					if v.pref.is_stats {
+						cgen.genln('BenchedTests_testing_step_start(&bt, tos3("$f.name"));') }
 					cgen.genln('$f.name ();')
 					if v.pref.is_stats { cgen.genln('BenchedTests_testing_step_end(&bt);') }
 				}

vlib/compiler/parser.v

@@ -1408,7 +1408,7 @@ fn ($v.name mut $v.typ) $p.cur_fn.name (...) {
 	//}
 	if expr_type == 'void' {
 		_, fn_name := p.is_expr_fn_call(p.token_idx-3)
-		p.error_with_token_index('$fn_name() $err_used_as_value', p.token_idx-2)
+		p.error_with_token_index('${fn_name}() $err_used_as_value', p.token_idx-2)
 	}
 	// Allow `num = 4` where `num` is an `?int`
 	if p.assigned_type.starts_with('Option_') &&
@@ -1517,7 +1517,7 @@ fn (p mut Parser) var_decl() {
 	t := p.gen_var_decl(p.var_decl_name, is_static)
 	if t == 'void' {
 		_, fn_name := p.is_expr_fn_call(p.token_idx-3)
-		p.error_with_token_index('$fn_name() $err_used_as_value', p.token_idx-2)
+		p.error_with_token_index('${fn_name}() $err_used_as_value', p.token_idx-2)
 	}
 	mut var_types := [t]
 	// multiple returns types
@@ -1698,7 +1698,7 @@ fn (p mut Parser) get_c_func_type(name string) string {
 		// Do not allow it.
 		if !name.starts_with('gl') && !name.starts_with('glad') {
 		p.error('undefined C function `$f.name`\n' +
-			'define it with `fn C.$name([args]) [return_type]`')
+			'define it with `fn C.${name}([args]) [return_type]`')
 		}
 		return 'void*'
 	}
@@ -2534,7 +2534,7 @@ if (!$tmp) {
      tos3("$filename"),
      $p.scanner.line_nr,
      tos3("$sourceline"),
-     tos3("$p.cur_fn.name()")
+     tos3("${p.cur_fn.name}()")
   );
   exit(1);
   // TODO
@@ -2545,7 +2545,7 @@ if (!$tmp) {
      tos3("$filename"),
      $p.scanner.line_nr,
      tos3("$sourceline"),
-     tos3("$p.cur_fn.name()")
+     tos3("${p.cur_fn.name}()")
   );
 }
 
@@ -2745,7 +2745,7 @@ fn (p mut Parser) js_decode() string {
 		decl += 'cJSON* $cjson_tmp = json__json_parse($expr);'
 		p.cgen.insert_before(decl)
 		// p.gen('jsdecode_$typ(json_parse($expr), &$tmp);')
-		p.gen('json__jsdecode_$typ($cjson_tmp, &$tmp); cJSON_Delete($cjson_tmp);')
+		p.gen('json__jsdecode_${typ}($cjson_tmp, &$tmp); cJSON_Delete($cjson_tmp);')
 		opt_type := 'Option_$typ'
 		p.cgen.typedefs << 'typedef Option $opt_type;'
 		p.table.register_builtin(opt_type)
@@ -2757,7 +2757,7 @@ fn (p mut Parser) js_decode() string {
 		T := p.table.find_type(typ)
 		p.gen_json_for_type(T)
 		p.check(.rpar)
-		p.gen('json__json_print(json__jsencode_$typ($expr))')
+		p.gen('json__json_print(json__jsencode_${typ}($expr))')
 		return 'string'
 	}
 	else {

vlib/compiler/query.v

@@ -123,7 +123,8 @@ fn (p mut Parser) select_query(fn_ph int) string {
 			if field.typ == 'int' {
 				cast = 'v_string_int'
 			}
-			obj_gen.writeln('${qprefix}$tmp . $field.name = $cast( *(string*)array_get(${qprefix}row.vals, $i) );')
+			obj_gen.writeln('${qprefix}${tmp}.$field.name = ' +
+				'${cast}(*(string*)array_get(${qprefix}row.vals, $i));')
 		}
 		// One object
 		if query_one {

vlib/compiler/scanner.v

@@ -299,7 +299,8 @@ fn (s mut Scanner) scan() ScanRes {
 			}
 		}
 		// end of `$expr`
-		if s.inter_start && next_char != `.` {
+		// allow `'$a.b'` and `'$a.c()'`
+		if s.inter_start && next_char != `.` && next_char != `(` {
 			s.inter_end = true
 			s.inter_start = false
 		}
@@ -315,6 +316,16 @@ fn (s mut Scanner) scan() ScanRes {
 		num := s.ident_number()
 		return scan_res(.number, num)
 	}
+	// Handle `'$fn()'`
+	if c == `)` && s.inter_start {
+		s.inter_end = true
+		s.inter_start = false
+		next_char := if s.pos + 1 < s.text.len { s.text[s.pos + 1] } else { `\0` }
+		if next_char == s.quote {
+			s.inside_string = false
+		}
+		return scan_res(.rpar, '')
+	}
 	// all other tokens
 	match c {
 	`+` {
@@ -383,8 +394,7 @@ fn (s mut Scanner) scan() ScanRes {
 		return scan_res(.rsbr, '')
 	 }
 	 `{` {
-		// Skip { in ${ in strings
-		// }
+		// Skip { in `${` in strings
 		if s.inside_string {
 			return s.scan()
 		}

vlib/compiler/table.v

@@ -188,7 +188,7 @@ const (
 fn (f Fn) str() string {
 	t := Table{}
 	str_args := f.str_args(t)
-	return '$f.name($str_args) $f.typ'
+	return '${f.name}($str_args) $f.typ'
 }
 
 pub fn (t &Table) debug_fns() string {

vlib/sdl/examples/tvintris/tvintris.v

@@ -676,7 +676,7 @@ fn (g mut Game) generate_tetro() {
 	g.pos_x = FieldWidth / 2 - TetroSize / 2
 	g.tetro_idx = g.rand_tetro()
 //	println('idx=${g.tetro_idx}')
-	g.tetro_stats[g.tetro_idx] += 1
+	g.tetro_stats[g.tetro_idx]+= 2 -1
 	g.tetro_total++
 	g.rotation_idx = 0
 	g.get_tetro()