Parsing iOS/macOS localizable strings file with antlr4 - xcode

Question

I am trying to parse the localized "strings" files of macOS/iOS.
The format of this file is based on key/value pairs, with optional comments. An example follows:
/* This is a comment */
// This is also a comment
"key1" = "value1";
"key2" = "value2";
and so on. NOTE inside the "" could be absolutely any kind of text.
EDIT Original errorneus grammar removed
I tried to write this simple grammar, but unfortunately it doesn't work.
Since the contents inside the quotes could be quite tricky, not to mention the comments, I feel that usual regex has no real power there.
EDIT based on the comments by #GRosenberg I've created a new grammar. Now I have the problem that I can't include "Symbols" as a Char, or else parsing will break.
grammar LProj;
Esc : '\\';
Spaces : [ \t\r\n\f]+;
BlockComment : '/*' .*? ('*/' | EOF) ;
LineComment : '//' ~[\r\n]* ( '\r'? '\n' [ \t]* '//' ~[\r\n]* )* ;
MLN_COMMENT: BlockComment -> channel(HIDDEN) ;
SLN_COMMENT: LineComment -> channel(HIDDEN) ;
doc : expression*;
expression
: BlockComment
| LineComment
| Spaces
| entry
;
entry : '"' key=VALUE '"' Spaces? '=' Spaces? '"' value=VALUE '"' Spaces? ';' ;
VALUE : ( EscSeq | Val )+ ;
fragment Val : Char ( EscSeq | Char )* ;
fragment Symbol
: '*'
| '/'
| ';'
| '='
;
fragment Char
: Spaces
| '!' // skip "
| '#'..')' // skip *
| '+'..'.' // skip /
| '0'..':' // skip ;
| '<' // skip =
| '>'..'[' // skip \
| ']'..'~'
| '\u00B7'..'\ufffd'
; // ignores | ['\u10000-'\uEFFFF] ;
fragment UnicodeEsc
: 'u' (Hex (Hex (Hex Hex?)?)?)?
;
fragment Hex : [0-9a-fA-F] ;
fragment EscSeq
: Esc
( [btnfr"\\] // standard escaped character set
| UnicodeEsc // standard Unicode escape sequence
| . // Invalid escape character
| EOF // Incomplete at EOF
)
;

Answer 1

The Antlr grammar repository, provides good examples of how to achieve the stated goal. Just define the ID terminal to allow for inclusion of escape sequences.
Thus (with obvious details omitted),
id : QUOTE key=ID EQ val=ID QUOTE ;
DOC_COMMENT: DocComment -> channel(HIDDEN) ;
MLN_COMMENT: BlockComment -> channel(HIDDEN) ;
SLN_COMMENT: LineComment -> channel(HIDDEN) ;
NAME : NameStartChar NameChar* ;
VALUE : ( EsqSeq | Val )+ ;
fragment Val : NameStartChar ( EsqSeq | NameChar )* ;
fragment Hws : [ \t] ;
fragment Vws : [\r\n\f] ;
fragment DocComment : '/**' .*? ('*/' | EOF) ;
fragment BlockComment : '/*' .*? ('*/' | EOF) ;
fragment LineComment : '//' ~[\r\n]* ( '\r'? '\n' Hws* '//' ~[\r\n]* )* ;
// escaped short-cut character or Unicode literal
fragment EscSeq
: Esc
( [btnfr"\\] // standard escaped character set
| UnicodeEsc // standard Unicode escape sequence
| . // Invalid escape character
| EOF // Incomplete at EOF
)
;
fragment Esc : '\\' ;
fragment UnicodeEsc
: 'u' (Hex (Hex (Hex Hex?)?)?)?
;
// A valid hex digit
fragment Hex : [0-9a-fA-F] ;
fragment NameChar
: NameStartChar
| '0'..'9'
| '_'
| '\u00B7'
| '\u0300'..'\u036F'
| '\u203F'..'\u2040'
;
fragment NameStartChar
: 'A'..'Z'
| 'a'..'z'
| '\u00C0'..'\u00D6'
| '\u00D8'..'\u00F6'
| '\u00F8'..'\u02FF'
| '\u0370'..'\u037D'
| '\u037F'..'\u1FFF'
| '\u200C'..'\u200D'
| '\u2070'..'\u218F'
| '\u2C00'..'\u2FEF'
| '\u3001'..'\uD7FF'
| '\uF900'..'\uFDCF'
| '\uFDF0'..'\uFFFD'
; // ignores | ['\u10000-'\uEFFFF] ;