Control Flow Formatting Rules

§5 Control Flow

§5.1 if expression. The if keyword is separated from the condition by a space, and the condition is separated from the code block by a space.

// ✅ Correct
if condition { ... }

// ❌ Incorrect
if(condition) { ... }
if condition{ ... }

§5.2 else if/else. else if and else are separated from the preceding code block by a space.

// ✅ Correct
if a > 0 { ... } else if a < 0 { ... } else { ... }

// ❌ Incorrect
if a > 0 { ... }else if a < 0 { ... }else { ... }

§5.3 for loop. The for keyword, the variable, the in keyword, and the iterator are separated by spaces.

// ✅ Correct
for item in collection { ... }

// ❌ Incorrect
for item in(collection) { ... }
for(item) in collection { ... }

§5.4 while loop. The while keyword is separated from the condition by a space.

// ✅ Correct
while condition { ... }

// ❌ Incorrect
while(condition) { ... }

§5.5 Loop labels. The label is connected to the loop keyword by : .

// ✅ Correct
'outer: for i in range(10) { ... }

// ❌ Incorrect
'outer:for i in range(10) { ... }
'outer : for i in range(10) { ... }

§5.6.1 Return format. The return keyword is separated from the expression by a space.

// ✅ Correct
return 42;
return x + y;

// ❌ Incorrect
return(42);  // Missing space
return  42;  // Extra space

§5.6.2 Empty return. An empty return uses the return keyword directly.

// ✅ Correct
return;

// ❌ Incorrect
return ;  // Extra space
return void;  // void is not needed

§5.7.1 Break format. The break keyword is separated from the label by a space.

// ✅ Correct
break;
break 'outer;

// ❌ Incorrect
break(outer);  // Invalid syntax
break  'outer;  // Extra space

§5.8.1 Continue format. The continue keyword is separated from the label by a space.

// ✅ Correct
continue;
continue 'outer;

// ❌ Incorrect
continue(outer);  // Invalid syntax
continue  'outer;  // Extra space