[SR-8507] 'foo bar' could have fixit suggesting missing . rather than just ; or ,

Previous ID	SR-8507
Radar	rdar://problem/25290712
Original Reporter	@huonw
Type	Bug

Master at 2018-08-09

Votes	0
Component/s	Compiler
Labels	Bug, Parser, StarterBug
Assignee	None
Priority	Medium

md5: 2e0b2de995cd56da9923536462d8ef0c

Issue Description:

For instance, in the following code, the mistake is missing the ., not missing a ;

struct Foo {
    var bar = 0
}

let foo = Foo()

let something = 1 + foo bar 
foo bar = 1
print(foo bar)

The errors for each of the three invalid lines are:

space.swift:7:24: error: consecutive statements on a line must be separated by ';'
let something = 1 + foo bar 
                       ^
                       ;
space.swift:7:19: error: binary operator '+' cannot be applied to operands of type 'Int' and 'Foo'
let something = 1 + foo bar 
                ~ ^ ~~~
space.swift:7:19: note: expected an argument list of type '(Int, Int)'
let something = 1 + foo bar 
                  ^
space.swift:7:25: error: use of unresolved identifier 'bar'
let something = 1 + foo bar 
                        ^~~

space.swift:8:4: error: consecutive statements on a line must be separated by ';'
foo bar = 1
   ^
   ;
space.swift:8:1: warning: expression of type 'Foo' is unused
foo bar = 1
^~~
space.swift:8:5: error: use of unresolved identifier 'bar'
foo bar = 1
    ^~~

space.swift:9:11: error: expected ',' separator
print(foo bar)
          ^
         ,
space.swift:9:11: error: use of unresolved identifier 'bar'
print(foo bar)
          ^~~

If it looks like an property access (or even a method call) might be valid (i.e. the thing after the space is an identifier), the compiler could guess at using . rather than/as well as ; or ,.