Conditional clauses (GNU Algol 68 Coding Guidelines)

### 4.3 Conditional clauses ¶

If a conditional clause is still clear and not of excessive length when written on a single line, just do it.

Start the enquiry clause in the if-part of a conditional clause right after the `if` symbol, not in the next line.

The serial clauses in the then- and else-parts of the conditional clause shall be indented five positions right, which is the length of both the `then` and `else` symbols plus one.

The first declaration or unit in the then- and else-parts shall be placed in the same line than the `then` and `else` symbols, respectively.

Place the `fi` closing symbol in its own line, with the same indentation level than the matching `if`. The exception to this rule is when the conditional clause has no else-part and the then-part spans for a single line that is not too long. In that case, place the `fi` in the same line than `then`.

Examples:

    { Very small conditional clause in a single line }
    if idx < 0 then fatal("invalid idx") fi

    { Short conditional-clause with `fi' in the same line
      than `then' }
    if argc /= 3
    then puts("expected two arguments'n") fi

    { A conditional-clause that spans several lines }
    if a > 10
    then puts("truncating");
         a := 10
    fi