• anonymous (35/35) Jan 12 2003 Two features that I like and may not be difficult to put in a compiler a...
• Walter (10/45) Jan 12 2003 Some sort of foreach is going to get added. It's just the particular

anonymous <anonymous_member pathlink.com> writes:

Two features that I like and may not be difficult to put in a compiler are
1) using statement
2) foreach statement

The using statement is a block that calls dispose() at the end to cleanup
resourses.  For example:
using(DatabaseConnection db = new DatabaseConnection()) {
db.open();
// various statements
}

is converted to the following code:

DatabaseConnection db = new DatabaseConnection();
try {
db.open();
// various statements
}
finally {
db.dispose();  
}

The using statement encourages connections, files, etc to get closed at the end
of the block with a syntax that is easy to read.  The converted code uses a try
block, but you learn at the end that the block is only used for managing
resources, not error handling.  The using statement is clearer, b/c it declares
up front that the block is for managing resources.

The other statement I like is foreach.  You guys probably know it well.  Quickly
it is:
foreach(string str in myArray) {
//stuff
}

is the same as:
IEnumerator enum = myArray.GetEnumerator();
while(enum.moveNext()) {
string str = (string)enum.current();  //is there a type-safe way of doing this?
//stuff
}

The myArray object implements IEnumerable (not IEnumerator).

"Walter" <walter digitalmars.com> writes:

Some sort of foreach is going to get added. It's just the particular
syntax/semantics that needs to be worked out. for the "using statement", I
think that the auto attribute should fit the bill. -Walter

"anonymous" <anonymous_member pathlink.com> wrote in message
news:avsl07$egn$1 digitaldaemon.com...
 Two features that I like and may not be difficult to put in a compiler are
 1) using statement
 2) foreach statement

 The using statement is a block that calls dispose() at the end to cleanup
 resourses.  For example:
 using(DatabaseConnection db = new DatabaseConnection()) {
 db.open();
 // various statements
 }

 is converted to the following code:

 DatabaseConnection db = new DatabaseConnection();
 try {
 db.open();
 // various statements
 }
 finally {
 db.dispose();
 }

 The using statement encourages connections, files, etc to get closed at

the end
 of the block with a syntax that is easy to read.  The converted code uses

a try
 block, but you learn at the end that the block is only used for managing
 resources, not error handling.  The using statement is clearer, b/c it

declares
 up front that the block is for managing resources.

 The other statement I like is foreach.  You guys probably know it well.

Quickly
 it is:
 foreach(string str in myArray) {
 //stuff
 }

 is the same as:
 IEnumerator enum = myArray.GetEnumerator();
 while(enum.moveNext()) {
 string str = (string)enum.current();  //is there a type-safe way of doing

this?
 //stuff
 }

 The myArray object implements IEnumerable (not IEnumerator).