Re: [Vala] Handling strings

[Al Thomas <astavale yahoo co uk>]

> From: Sascha Manns <Sascha Manns mailbox org>
> Sent: Wednesday, 19 April 2017, 13:42
> Subject: Re: [Vala] Handling strings

> I tried it out in that way:
> // Constants used by create_publication_core
>     private string _filename;
>     private string _path;
>     private const string REV_HIST = "Revision_History.xml";
>     private const string AUTHOR_GROUP = "Author_Group.xml";
>     private const string ENTITY_FILE_SUFFIX = ".ent";
>     private const string DIRECTORY_SEPARATOR_CHAR = "/";
>     private const string ENTITY_FILE_LOCAL = {get {_filename =
> publication_title + ENTITY_FILE_SUFFIX; return _filename;}}

> The compiler says:
> core/create_publication_core.vala:51.48-51.48: error: syntax error,
> expected `}'
>         private const string ENTITY_FILE_LOCAL = {get {_filename =
> publication_title + ENTITY_FILE_SUFFIX; return _filename;}}
                                                      ^

> Maybe i miss anything?

You've added 'const'. It should be:

private string ENTITY_FILE_LOCAL = {get {_filename =
 publication_title + ENTITY_FILE_SUFFIX; return _filename;}}

Constants do not change during the running of the program. They can, however,
be concatenated at compile time. So you could do:
private const string PATH = DIRECTORY_SEPARATOR_CHAR + AUTHOR_GROUP;

If the field is changeable during the running of the program then it shouldn't
be marked as 'const'.

By the way, GLib has a constant already for directory separator:
https://valadoc.org/glib-2.0/GLib.Path.DIR_SEPARATOR.html