The semicolon inference doesn't work when an assignment statement is followed by curly braces in Scala? -

@ http://www.artima.com/pins1ed/builtin-control-structures.html#7.7 , see following code

val = 1; {   val = 2   println(a) } println(a) 

where says semicolon required here, why?

from rule @ http://www.artima.com/pins1ed/classes-and-objects.html#4.2 , think semicolon should auto added since

1. val = 1 can legal statement.
2. the next line begins {, think can start legal statement. (since there's no compile error if add semicolon , separate first 2 lines 2 statements.)
3. val = 1 not in parentheses or brackets.

because legal call apply:

implicit class richint(i: int) {   def apply(thunk: => unit) = 33 }  val = 1 {   val = 2   println(a) } println(a)  // 33 ! 

1 { ... } short 1.apply {...}. apply not defined int default, implicit enrichment shows, possible.

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edit: semicolon inference conditions described in '§1.2 newline characters' of scala language specification. inferred semicolon called 'special token "nl"' in text.

in general, 3 rules given (summarised ex-negativo in blog entry), , in example satisfied. reason semicolon still not inferred given further down in text.

the scala grammar ... contains productions optional nl tokens, not semicolons, accepted. has effect newline in 1 of these positions not [!] terminate expression or statement.

the relevant case of such rule following:

a single new line token accepted
– in front of opening brace “{”, if brace legal continuation of current statement or expression ...

example 1.2.2 shows case of anonymous subclass had referred in comment.