For non-terminated strings (and characters), the scanner returns a literal that is
longer (by one character) than is necessary. Example:

$ cat x.go
package p

import (
    "foo
)

$ gotype -trace x.go
    1:  1: File (
    1:  1: . "package"
    1:  9: . IDENT p
    1: 10: . ";"
    3:  1: . GenDecl(import) (
    3:  1: . . "import"
    3:  8: . . "("
    4:  2: . . ImportSpec (
    4:  2: . . . STRING "foo
)
    5:  2: . . . ";"
    5:  3: . . )
    5:  3: . . EOF
    5:  3: . )
    5:  3: )
x.go:4:2: string not terminated
x.go:5:3: expected ')', found 'EOF'

The reported literal value for the non-terminated string "foo is
"\"foo\n)" rather than just  "\"foo\n" (extra ) at end).
This can lead to worse parser token synchronization in error situations than necessary.