gen: fix multiple call of expression in match (#6324)

cmd/tools/vbuild-examples.v

@@ -7,13 +7,10 @@ fn main() {
 	args := os.args
 	args_string := args[1..].join(' ')
 	params := args_string.all_before('build-examples')
-
 	if testing.v_build_failing(params, 'examples') {
 		exit(1)
 	}
-
 	if testing.v_build_failing(params + '-live', os.join_path('examples', 'hot_reload')) {
 		exit(1)
 	}
-
 }

examples/2048/2048.v

@@ -180,7 +180,9 @@ fn (t TileLine) to_left() TileLine {
 fn (b Board) to_left() Board {
 	mut res := b
 	for y := 0; y < 4; y++ {
-		mut hline := TileLine{ypos: y}
+		mut hline := TileLine{
+			ypos: y
+		}
 		for x := 0; x < 4; x++ {
 			hline.field[x] = b.field[y][x]
 		}
@@ -379,7 +381,8 @@ fn (mut app App) game_over() {
 	app.state = .over
 }
 
-type BoardMoveFN fn(b Board) Board
+type BoardMoveFN = fn (b Board) Board
+
 fn (mut app App) move(move_fn BoardMoveFN) {
 	old := app.board
 	new := move_fn(old)

examples/sokol/particles/particles.v

@@ -36,7 +36,10 @@ mut:
 fn (mut a App) init() {
 	a.frame = 0
 	a.last = time.ticks()
-	a.ps = particle.System{width: a.width, height: a.height}
+	a.ps = particle.System{
+		width: a.width
+		height: a.height
+	}
 	a.ps.init(particle.SystemConfig{
 		pool: 20000
 	})
@@ -59,7 +62,6 @@ fn (mut a App) run() {
 		html5_canvas_name: title.str
 		cleanup_userdata_cb: cleanup
 	}
-
 	sapp.run(&desc)
 }
 
@@ -119,13 +121,10 @@ fn event(ev &C.sapp_event, user_data voidptr) {
 			}
 		}
 	}
-
 	if ev.@type == .touches_began || ev.@type == .touches_moved {
 		if ev.num_touches > 0 {
-
 			touch_point := ev.touches[0]
 			app.ps.explode(touch_point.pos_x, touch_point.pos_y)
-
 		}
 	}
 }

examples/vweb/vweb_assets/vweb_assets.v

@@ -27,18 +27,17 @@ pub fn (mut app App) init_once() {
 	// app.vweb.handle_static('.')
 }
 
-pub fn (mut app App) init() {}
+pub fn (mut app App) init() {
+}
 
 pub fn (mut app App) index() {
 	// We can dynamically specify which assets are to be used in template.
 	mut am := assets.new_manager()
 	am.add_css('assets/index.css')
-
 	css := am.include_css(false)
 	title := 'VWeb Assets Example'
 	subtitle := 'VWeb can serve static assets too!'
 	message := 'It also has an Assets Manager that allows dynamically specifying which CSS and JS files to be used.'
-
 	$vweb.html()
 }
 

vlib/v/gen/cgen.v

@@ -2561,15 +2561,17 @@ fn (mut g Gen) match_expr(node ast.MatchExpr) {
 			g.match_sumtype_syms.pop()
 		}
 	}
-	mut tmp := ''
-	if type_sym.kind != .void {
-		tmp = g.new_tmp_var()
+	cur_line := if is_expr {
+		g.empty_line = true
+		g.go_before_stmt(0)
+	} else {
+		''
 	}
-	// styp := g.typ(node.expr_type)
-	// g.write('$styp $tmp = ')
-	// g.expr(node.cond)
-	// g.writeln(';') // $it.blocks.len')
-	// mut sum_type_str = ''
+	cond_var := g.new_tmp_var()
+	g.write('${g.typ(node.cond_type)} $cond_var = ')
+	g.expr(node.cond)
+	g.writeln(';')
+	g.write(cur_line)
 	for j, branch in node.branches {
 		is_last := j == node.branches.len - 1
 		if branch.is_else || (node.is_expr && is_last) {
@@ -2596,7 +2598,7 @@ fn (mut g Gen) match_expr(node ast.MatchExpr) {
 			}
 			for i, expr in branch.exprs {
 				if node.is_sum_type {
-					g.expr(node.cond)
+					g.write(cond_var)
 					sym := g.table.get_type_symbol(node.cond_type)
 					// branch_sym := g.table.get_type_symbol(branch.typ)
 					if sym.kind == .sum_type {
@@ -2610,26 +2612,23 @@ fn (mut g Gen) match_expr(node ast.MatchExpr) {
 					g.expr(expr)
 				} else if type_sym.kind == .string {
 					g.write('string_eq(')
-					//
-					g.expr(node.cond)
+					g.write(cond_var)
 					g.write(', ')
-					// g.write('string_eq($tmp, ')
 					g.expr(expr)
 					g.write(')')
 				} else if expr is ast.RangeExpr {
 					g.write('(')
-					g.expr(node.cond)
+					g.write(cond_var)
 					g.write(' >= ')
 					g.expr(expr.low)
 					g.write(' && ')
-					g.expr(node.cond)
+					g.write(cond_var)
 					g.write(' <= ')
 					g.expr(expr.high)
 					g.write(')')
 				} else {
-					g.expr(node.cond)
+					g.write(cond_var)
 					g.write(' == ')
-					// g.write('$tmp == ')
 					g.expr(expr)
 				}
 				if i < branch.exprs.len - 1 {
@@ -2652,7 +2651,7 @@ fn (mut g Gen) match_expr(node ast.MatchExpr) {
 					it_type := g.typ(first_expr.typ)
 					// g.writeln('$it_type* it = ($it_type*)${tmp}.obj; // ST it')
 					g.write('\t$it_type* it = ($it_type*)')
-					g.expr(node.cond)
+					g.write(cond_var)
 					dot_or_ptr := if node.cond_type.is_ptr() { '->' } else { '.' }
 					g.write(dot_or_ptr)
 					g.writeln('_object; // ST it')

vlib/v/tests/match_test.v

@@ -118,6 +118,28 @@ fn test_match_enums() {
 	assert b == .blue
 }
 
+struct Counter {
+mut:
+	val int
+}
+
+fn (mut c Counter) next() int {
+	c.val++
+	return c.val
+}
+
+fn test_method_call() {
+	mut c := Counter{
+		val: 1
+	}
+	assert match c.next() {
+		1 { false }
+		2 { true }
+		3 { false }
+		else { false }
+	}
+}
+
 type Sum = A1 | B1
 
 struct A1 {