Style of if expressions used as ternary operators?

[dhardy]

Any recommendations on (white-space formatting of) the following?

let val = if some_long_and_complex_condition() {
    val_a
} else {
    val_b
};

verse something more condensed like:

// ugly, but at least not overly long:
let val = if some_long_and_complex_condition() {
    val_a } else { val_b };

[chris-morgan]

For starters, there should always be whitespace around curly braces with the exception of after a closing brace followed by certain pieces of punctuation (), ], , and ; being the ones that occur to me initially).

For the rest, I would say either is acceptable, but once must take into account the line length limits (99 characters) and æsthetic concerns which may easily render the single-line version undesirable.

[dhardy]

Updated spacing to reflect chris-morgan's comment. I would consider single-line formatting not to be a problem, but my example was meant to ask about cases too long for a single line.

[donsignore]

Additional alternative easy for humans to parse:

let val = if some_long_and_complex_condition() {
    val_a } else {
    val_b };

or:

let val = if some_long_and_complex_condition() {
        val_a } else {
        val_b };