From 8f9b6ac2489823a54641faaf4a7883e2c0b02c4e Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Sun, 8 Dec 2019 22:22:47 +0300
Subject: [PATCH] '$foo()' string interpolation

---
 vlib/compiler/compile_errors.v        |  2 +-
 vlib/compiler/comptime.v              |  2 +-
 vlib/compiler/fn.v                    | 16 +++++++++-------
 vlib/compiler/gen_c.v                 |  8 ++++----
 vlib/compiler/json_gen.v              | 22 +++++++++++-----------
 vlib/compiler/main.v                  |  8 +++++---
 vlib/compiler/parser.v                | 18 +++++++++---------
 vlib/compiler/query.v                 |  3 ++-
 vlib/compiler/scanner.v               | 16 +++++++++++++---
 vlib/compiler/table.v                 |  2 +-
 vlib/sdl/examples/tvintris/tvintris.v |  2 +-
 11 files changed, 57 insertions(+), 42 deletions(-)

diff --git a/vlib/compiler/compile_errors.v b/vlib/compiler/compile_errors.v
index 7fa0c861e4..4d0a8f89c4 100644
--- a/vlib/compiler/compile_errors.v
+++ b/vlib/compiler/compile_errors.v
@@ -242,7 +242,7 @@ fn (p mut Parser) mutable_arg_error(i int, arg Var, f Fn) {
 		dots_example = dots_example + ',..'
 	}
 	p.error('`$arg.name` is a mutable argument, you need to provide `mut`: ' +
-			'`$f.name($dots_example)`')
+			'`$f.name ($dots_example)`')
 }
 
 const (
diff --git a/vlib/compiler/comptime.v b/vlib/compiler/comptime.v
index ed9cb7a903..14321be008 100644
--- a/vlib/compiler/comptime.v
+++ b/vlib/compiler/comptime.v
@@ -279,7 +279,7 @@ fn (p mut Parser) comptime_method_call(typ Type) {
 			p.gen(' else ')
 		}
 		p.genln('if ( string_eq($var, _STR("$method.name")) ) ' +
-			'${typ.name}_$method.name($amp $p.expr_var.name);')
+			'${typ.name}_$method.name ($amp $p.expr_var.name);')
 		j++
 	}
 	p.check(.lpar)
diff --git a/vlib/compiler/fn.v b/vlib/compiler/fn.v
index a8c9319b25..173415dff7 100644
--- a/vlib/compiler/fn.v
+++ b/vlib/compiler/fn.v
@@ -455,7 +455,7 @@ fn (p mut Parser) fn_decl() {
 	}
 
 	if is_fn_header {
-		p.genln('$typ $fn_name_cgen($str_args);')
+		p.genln('$typ $fn_name_cgen ($str_args);')
 		p.fgen_nl()
 	}
 	if is_c {
@@ -495,7 +495,7 @@ fn (p mut Parser) fn_decl() {
 			fn_name_cgen = '(* $fn_name_cgen )'
 		}
 		// Function definition that goes to the top of the C file.
-		mut fn_decl := '$dll_export_linkage$typ $fn_name_cgen($str_args)'
+		mut fn_decl := '$dll_export_linkage$typ $fn_name_cgen ($str_args)'
 		if p.pref.obfuscate {
 			fn_decl += '; // $f.name'
 		}
@@ -692,7 +692,7 @@ fn (p mut Parser) async_fn_call(f Fn, method_ph int, receiver_var, receiver_type
 	if p.os == .windows {
 		wrapper_type = 'DWORD WINAPI'
 	}
-	wrapper_text := '$wrapper_type $wrapper_name($arg_struct_name * arg) {$fn_name( /*f*/$str_args ); return 0; }'
+	wrapper_text := '$wrapper_type $wrapper_name ($arg_struct_name * arg) {$fn_name ( /*f*/$str_args ); return 0; }'
 	p.cgen.register_thread_fn(wrapper_name, wrapper_text, arg_struct)
 	// Create thread object
 	tmp_nr := p.get_tmp_counter()
@@ -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 {
diff --git a/vlib/compiler/gen_c.v b/vlib/compiler/gen_c.v
index 5e8e2e92fd..ceb3276b3d 100644
--- a/vlib/compiler/gen_c.v
+++ b/vlib/compiler/gen_c.v
@@ -60,7 +60,7 @@ fn (p mut Parser) gen_fn_decl(f Fn, typ, str_args string) {
 	}
 	fn_name_cgen := p.table.fn_gen_name(f)
 	//str_args := f.str_args(p.table)
-	p.genln('$dll_export_linkage$typ $fn_name_cgen($str_args) {')
+	p.genln('$dll_export_linkage$typ $fn_name_cgen ($str_args) {')
 }
 
 // blank identifer assignment `_ = 111`
@@ -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')
diff --git a/vlib/compiler/json_gen.v b/vlib/compiler/json_gen.v
index e7c1a33d36..42b6057090 100644
--- a/vlib/compiler/json_gen.v
+++ b/vlib/compiler/json_gen.v
@@ -57,8 +57,8 @@ fn (p mut Parser) gen_json_for_type(typ Type) {
 	p.table.register_fn(enc_fn)
 	// Code gen decoder
 	dec += '
-//$t $dec_fn.name(cJSON* root) {
-Option $dec_fn.name(cJSON* root, $t* res) {
+//$t $dec_fn.name (cJSON* root) {
+Option ${dec_fn.name}(cJSON* root, $t* res) {
 //  $t res;
   if (!root) {
     const char *error_ptr = cJSON_GetErrorPtr();
@@ -71,7 +71,7 @@ Option $dec_fn.name(cJSON* root, $t* res) {
 '
 	// Code gen encoder
 	enc += '
-cJSON* $enc_fn.name($t val) {
+cJSON* $enc_fn.name ($t val) {
 cJSON *o = cJSON_CreateObject();
 string res = tos2("");
 '
@@ -96,24 +96,24 @@ string res = tos2("");
 		if field.attr == 'raw' {
 			dec += ' res->$field.name = tos2(cJSON_PrintUnformatted(' +
 				'js_get(root, "$name")));\n'
-			
+
 		} else {
 			// Now generate decoders for all field types in this struct
 			// need to do it here so that these functions are generated first
 			p.gen_json_for_type(field_type)
-	
+
 			dec_name := js_dec_name(_typ)
 
 			if is_js_prim(_typ) {
-				dec += ' res->$field.name = $dec_name(js_get(' +
+				dec += ' res->$field.name = $dec_name (js_get(' +
 					'root, "$name"))'
 			}
 			else {
-				dec += ' $dec_name(js_get(root, "$name"), & (res->$field.name))'
+				dec += ' $dec_name (js_get(root, "$name"), & (res->$field.name))'
 			}
 			dec += ';\n'
 		}
-		enc += '  cJSON_AddItemToObject(o,  "$name",$enc_name(val.$field.name)); \n'
+		enc += '  cJSON_AddItemToObject(o,  "$name",$enc_name (val.$field.name)); \n'
 	}
 	// cJSON_delete
 	//p.cgen.fns << '$dec return opt_ok(res); \n}'
@@ -136,10 +136,10 @@ fn (p mut Parser) decode_array(array_type string) string {
 	p.gen_json_for_type(t)
 	mut s := ''
 	if is_js_prim(typ) {
-		s = '$typ val= $fn_name(jsval); '
+		s = '$typ val= $fn_name (jsval); '
 	}
 	else {
-		s = '  $typ val; $fn_name(jsval, &val); '
+		s = '  $typ val; $fn_name (jsval, &val); '
 	}
 	return '
 *res = new_array(0, 0, sizeof($typ));
@@ -168,7 +168,7 @@ fn (p &Parser) encode_array(array_type string) string {
 	return '
 o = cJSON_CreateArray();
 for (int i = 0; i < val.len; i++){
-  cJSON_AddItemToArray(o, $fn_name(  (($typ*)val.data)[i]  ));
+  cJSON_AddItemToArray(o, $fn_name (  (($typ*)val.data)[i]  ));
 }
 '
 }
diff --git a/vlib/compiler/main.v b/vlib/compiler/main.v
index 1a928c40c0..aa22165be2 100644
--- a/vlib/compiler/main.v
+++ b/vlib/compiler/main.v
@@ -502,13 +502,15 @@ 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("$f.name"));') }
-					cgen.genln('$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);') }
 				}
 			}
diff --git a/vlib/compiler/parser.v b/vlib/compiler/parser.v
index 1c5c74e866..7bfa27bbb9 100644
--- a/vlib/compiler/parser.v
+++ b/vlib/compiler/parser.v
@@ -1183,11 +1183,11 @@ fn (p mut Parser) free_var(v Var) {
 		if !v.is_returned && v.typ != 'FILE*' { //!v.is_c {
 			prev_line := p.cgen.lines[p.cgen.lines.len-2]
 			p.cgen.lines[p.cgen.lines.len-2] =
-				'$free_fn($v.name); /* :) close_scope free $v.typ */' + prev_line
+				'$free_fn ($v.name); /* :) close_scope free $v.typ */' + prev_line
 		}
 	} else {
 		//if p.fileis('mem.v') {println(v.name)}
-		p.genln('$free_fn($v.name); // close_scope free')
+		p.genln('$free_fn ($v.name); // close_scope free')
 	}
 }
 
@@ -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}($expr))')
 		return 'string'
 	}
 	else {
diff --git a/vlib/compiler/query.v b/vlib/compiler/query.v
index 862c0d0cc2..e9ba5387a8 100644
--- a/vlib/compiler/query.v
+++ b/vlib/compiler/query.v
@@ -123,7 +123,8 @@ fn (p mut Parser) select_query(fn_ph int) string {
 			if field.typ == 'int' {
 				cast = 'v_string_int'
 			}
-			obj_gen.writeln('${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, $i));')
 		}
 		// One object
 		if query_one {
diff --git a/vlib/compiler/scanner.v b/vlib/compiler/scanner.v
index c1cf0fc74d..846d9190d3 100644
--- a/vlib/compiler/scanner.v
+++ b/vlib/compiler/scanner.v
@@ -299,7 +299,8 @@ fn (s mut Scanner) scan() ScanRes {
 			}
 		}
 		// end of `$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()
 		}
diff --git a/vlib/compiler/table.v b/vlib/compiler/table.v
index 21825e86d2..9459a39efe 100644
--- a/vlib/compiler/table.v
+++ b/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 {
diff --git a/vlib/sdl/examples/tvintris/tvintris.v b/vlib/sdl/examples/tvintris/tvintris.v
index 403235bb27..d6838ef566 100644
--- a/vlib/sdl/examples/tvintris/tvintris.v
+++ b/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()