AllBASIC Forum
BASIC Developer & Support Resources => Translators => Topic started by: John on April 16, 2011, 05:23:08 PM
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Armando posted some examples of using the Vala/Genie to C translator if your interested in this language environment.
Has anyone looked into the Vala (http://live.gnome.org/Vala) language? It seems pretty cool.
I converted the Tiny Times example I did using Glade (http://basic-compiler.com/forum/index.php?PHPSESSID=f7ppm26556267ka3v6pupb2796&topic=45.msg146#msg146) as a test:
using Gtk;
Window window;
TextView textview;
public void button_clicked (Button source) {
var buf="";
var A = source.label;
for (int i = 1; i <= 15; i++) {
var res = i*A.to_int();
buf += " " + A + " x " + i.to_string() + " = " + res.to_string() + "\n";
}
textview.buffer.text = buf;
}
int main (string[] args) {
Gtk.init (ref args);
try {
var builder = new Builder ();
builder.add_from_file ("tt.ui");
builder.connect_signals (null);
window = builder.get_object ("window1") as Window;
textview = builder.get_object ("textview1") as TextView;
window.show_all ();
Gtk.main ();
} catch (Error e) {
stderr.printf ("Could not load UI: %s\n", e.message);
return 1;
}
return 0;
}
What's really nice about it is that you can code in an OO way (which my example is NOT) with all of it's benefits, but it comes out as "C", not "C++" and no extra "bloat".
It's modelled somewhat after C#, but no runtime. It uses GLib/GTK.
A.
(http://files.allbasic.info/Vala/TT-Vala.png)
Vala supports two syntax modes: "Vala" mode, which is like C#, and "Genie" mode which is like Python.
Here is the same example coded using Genie syntax:
[indent=2]
uses
Gtk
window:Window
textview:TextView
init
Gtk.init (ref args)
try
var builder = new Builder ()
builder.add_from_file ("tt.ui")
builder.connect_signals (null)
window = builder.get_object ("window1") as Window
textview = builder.get_object ("textview1") as TextView
window.show_all ()
Gtk.main ()
except e : Error
print "%s", e.message
def button_clicked(source:Button)
var buf=""
var A=source.label
for var i = 1 to 15
var res = i*A.to_int()
buf += " " + A + " x " + i.to_string() + " = " + res.to_string() + "\n"
textview.buffer.text = buf
How is string support with Vala? One of the major reasons I use ScriptBasic is I have virtually unlimited strings and I don't have to do a thing to declare or release them.
Using Project Gutenberg's "War and Peace" (http://www.gutenberg.org/files/2600/2600.txt), which weighs in at 3.1Megs:
[indent=2]
init
book:string = "Hello"
print("Initial String Variable Size: %d bytes",book.length)
try
FileUtils.get_contents("2600.txt", out book)
except e : Error
print("%s", e.message)
print("String Variable Size after loading \"War and Peace\" from file: %d bytes", book.length)
var x = book.split("\n")
print("Number of lines in \"War and Peace\": %d",x.length)
Initial String Variable Size: 5 bytes
String Variable Size after loading "War and Peace" from file: 3288739 bytes
Number of lines in "War and Peace": 65337
Hope that answers your question!
A.
They support MySql, LibXml2, SQlite, WebKit, and far more.....
I was surprised to see that cURL (libcurl) wasn't in the package list. I count on that library a lot.
That list only contains the "official" packages. libsoup is generally considered as the replacement, although it's not a simple "drop-in" replacement.
Anyway, the Maemo project (which Vala supports) has something in their scm for curl, which I've attached.
Unpack it, and copy the two files into your vapi folder (if you built 0.12.0 from source using the defaults, it should be located at /usr/local/share/vala-0.12/vapi/)
curl.gs
/*
compile with: valac --pkg curl curl.gs -X -lcurl
*/
[indent=2]
uses
Curl
init
var fp1 = FileStream.open("general.html","w")
var handle = new EasyHandle()
handle.setopt(Option.URL, "http://scriptbasic.com/html/general.html")
handle.setopt(Option.FILE, fp1)
handle.perform()
Note that because of the way Vala/Genie works, you don't need to close the file handle or the curl handle because they are automatically closed when they go out of scope. So if you were to place either in a sub/function, when that sub/function was exited the handles would be closed.
In this case, they are closed as the program exits.
Note also that by using "var" above, I don't have to "pre-declare" the variables. valac infers the type based on what comes after the "=" sign, and sets the type accordingly.
A.
cURL Vala Attachment (http://basic-compiler.com/forum/index.php?action=dlattach;topic=386.0;attach=435)
Here's an idea for MySQL. Not tested because I don't have it running:
/*
compile with: valac --pkg mysql mysql.gs -X -lmysqlclient
*/
[indent=2]
uses
Mysql
init
MysqlHost: string = ""
UserName: string = ""
Password: string = ""
DatabaseName: string = ""
var MysqlDB = new Mysql.Database()
MysqlDB.real_connect(MysqlHost, UserName, Password, DatabaseName, 0,"/tmp/mysql.sock")
var ReturnValue = MysqlDB.query("SELECT ")
var ResultSet = MysqlDB.use_result()
while !ResultSet.eof()
var MyRow = ResultSet.fetch_row()
if MyRow is not null
print " %s | %s", MyRow[0], MyRow[1]
A.
xmltest.vala
/*
Compile with: valac --pkg libxml-2.0 xmltest.vala -X -lxml2
*/
using Xml;
class XmlParser {
public void parse_file (string path) {
Xml.Doc* doc = Parser.parse_file (path);
if (doc == null) {
printerr("File %s not found or permissions missing\n", path);
return;
}
Xml.Node* root = doc->get_root_element ();
if (root == null) {
delete doc;
printerr("The xml file '%s' is empty\n", path);
return;
}
parse_node(root);
delete doc;
}
private void parse_node (Xml.Node* node) {
for (Xml.Node* iter = node->children; iter != null; iter = iter->next) {
if (iter->type != ElementType.ELEMENT_NODE) {
continue;
}
string node_name = iter->name;
string node_content = iter->get_content();
if (node_content.index_of(" ")==-1)
print("%s=%s\n",node_name,node_content);
parse_node(iter);
}
}
}
int main (string[] args) {
if (args.length < 2) {
stderr.printf ("Argument required!\n");
return 1;
}
Parser.init();
var sample = new XmlParser();
sample.parse_file (args[1]);
Parser.cleanup();
return 0;
}
Here's the same thing in GENIE:
xmltest.gs
/*
Compile with: valac --pkg libxml-2.0 xmltest.gs -X -lxml2
*/
[indent=2]
uses
Xml
class XmlParser
def parse_file (path: string )
doc: Xml.Doc*
root: Xml.Node*
doc = Parser.parse_file (path)
if doc is null
printerr ("File %s not found or permissions missing\n", path)
return
root = doc->get_root_element()
if root is null
delete doc
printerr ("The xml file '%s' is empty\n", path)
return
parse_node (root)
delete doc
def private parse_node (node: Xml.Node*)
iter: Xml.Node* = node->children
while (iter != null)
if (iter->type != ElementType.ELEMENT_NODE)
iter = iter->next
continue
var node_name = iter->name
var node_content = iter->get_content()
if (node_content.index_of(" ")==-1)
print("%s=%s",node_name,node_content)
parse_node(iter)
iter = iter->next
init
if (args.length < 2)
printerr("Argument required!\n")
return
Parser.init ()
var sample = new XmlParser()
sample.parse_file (args[1])
Parser.cleanup ()
uses
Curl
Xml
Mysql
OR
uses Curl, Xml, Mysql
You would most likely want to place each code block in a class so you could reuse it, but it's not neccessary.
If you put all of the code in a single file:
valac <file> --pkg curl --pkg libxml-2.0 --pkg mysql -X -lcurl -X -lxml2 -X -lmysqlclient
if you put them in separate files:
valac <file> <file> <file> --pkg curl --pkg libxml-2.0 --pkg mysql -X -lcurl -X -lxml2 -X -lmysqlclient
You could create a makefile or bash script to simplify things...
For readability, you can also group the related --pkg and -X and separate by spaces:
valac <file> --pkg curl -X -lcurl --pkg libxml-2.0 -X -lxml2 --pkg mysql -X -lmysqlclient
A.
curl.gs
/*
compile with: valac --pkg curl curl.gs -X -lcurl
*/
[indent=2]
uses
Curl
init
var fp1 = FileStream.open("general.html","w")
var handle = new EasyHandle()
handle.setopt(Option.URL, "http://scriptbasic.com/html/general.html")
handle.setopt(Option.FILE, fp1)
handle.perform()
Here's the same thing using libsoup:
[indent=2]
/* Build with valac --thread --pkg libsoup-2.4 yourfile.gs */
uses
Soup
init
var session = new Soup.SessionAsync ()
var message = new Soup.Message ("GET", "http://scriptbasic.com/html/general.html")
session.send_message (message)
try
FileUtils.set_contents("general.html", (string)message.response_body.data)
except e: Error
print("%s",e.message)
A.
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I was able to get Vala compiled from source on Ubuntu 10-10 64 bit. I had to install flex & bison and do a ldconfig after the install but all went well. I continue to follow along with Armando's adventures with Vala/Genie as his comfort level increases with his new environment.