mybearworld wrote:

Well, I think that it would be harder to implement… Just because it would have to sense if an { is there, and if it isn't, what then?
If we don't, what would this be:

repeat 20
me = Cat
}

Resince wrote:

Awesome idea, I've always wanted to make a programming language in Scratch that resembled the syntax of Javascript.

What I mean by this is:

var i = 0; // Creates a variable set to zero.
repeat (5) { // Repeat Loop
  i++; // Changes i by + 1
  say (i); // Prints i
}

gosoccerboy5 wrote:

Resince wrote:

Awesome idea, I've always wanted to make a programming language in Scratch that resembled the syntax of Javascript.

What I mean by this is:

var i = 0; // Creates a variable set to zero.
repeat (5) { // Repeat Loop
  i++; // Changes i by + 1
  say (i); // Prints i
}

That'd be pretty sweet. (Would there be like return functions and stuff, or would it be limited to Scratch abilities?)

mybearworld wrote:

Well, I think that it would be harder to implement… Just because it would have to sense if an { is there, and if it isn't, what then?
If we don't, what would this be:

repeat 20
me = Cat
}

while i > j +3
loop
# stuff
end

if (i > 3)
foo();
else
bar();

gosoccerboy5 wrote:

I'm torn between indentation and curly brackets - indentation might be more intuitive for Scratch users (concise syntax), but curly brackets might be easier for the parser(?) and would be easier to type in.

repeat 10
a();
repeat 5
b();
c();

repeat 10 {
a();
repeat 5 {
b();
c();
}
}

(pixels)(command px:: list)::operators

Greg8128 wrote:

mybearworld wrote:

Well, I think that it would be harder to implement… Just because it would have to sense if an { is there, and if it isn't, what then?
If we don't, what would this be:

repeat 20
me = Cat
}

if you had syntax like

while i > j +3
loop
# stuff
end

you would still have to detect the “loop” keyword. Even if you could find a way to not include it, you would still need to find a way to not include it.

If the ‘{’ is missing, you could throw a compile error as gosoccerboy suggested. Alternatively, you could just take the next statement as the body of the loop, which allows stuff such as:

if (i > 3)
foo();
else
bar();

In fact, you could handle the case with the ‘{’ using this method by implementing the {…} as a ‘compound statement’, or several statements that the compiler treats as one. This approach also has several other cool advantages that I can discuss if you want.

gosoccerboy5 wrote:

I'm torn between indentation and curly brackets - indentation might be more intuitive for Scratch users (concise syntax), but curly brackets might be easier for the parser(?) and would be easier to type in.

indentation-based syntax is problematic. Many people have their tabs set up differently in their text editors; some people have a tab equal 4 spaces, some have it equal 2 spaces, and so forth. So if you try to make your code look pretty, it could end up looking ugly for someone else. If you really want indentation based syntax, a simple implementation would be to insert a ‘{’ for every tab gained relative to the previous line and a ‘}’ for every tab lost relative to the previous line. So something like

repeat 10
a();
repeat 5
b();
c();

would be read by the compiler as:

repeat 10 {
a();
repeat 5 {
b();
c();
}
}

pedrodrocafranco wrote:

Greg8128 wrote:

mybearworld wrote:

Well, I think that it would be harder to implement… Just because it would have to sense if an { is there, and if it isn't, what then?
If we don't, what would this be:

repeat 20
me = Cat
}

if you had syntax like

while i > j +3
loop
# stuff
end

you would still have to detect the “loop” keyword. Even if you could find a way to not include it, you would still need to find a way to not include it.

If the ‘{’ is missing, you could throw a compile error as gosoccerboy suggested. Alternatively, you could just take the next statement as the body of the loop, which allows stuff such as:

if (i > 3)
foo();
else
bar();

In fact, you could handle the case with the ‘{’ using this method by implementing the {…} as a ‘compound statement’, or several statements that the compiler treats as one. This approach also has several other cool advantages that I can discuss if you want.

gosoccerboy5 wrote:

I'm torn between indentation and curly brackets - indentation might be more intuitive for Scratch users (concise syntax), but curly brackets might be easier for the parser(?) and would be easier to type in.

indentation-based syntax is problematic. Many people have their tabs set up differently in their text editors; some people have a tab equal 4 spaces, some have it equal 2 spaces, and so forth. So if you try to make your code look pretty, it could end up looking ugly for someone else. If you really want indentation based syntax, a simple implementation would be to insert a ‘{’ for every tab gained relative to the previous line and a ‘}’ for every tab lost relative to the previous line. So something like

repeat 10
a();
repeat 5
b();
c();

would be read by the compiler as:

repeat 10 {
a();
repeat 5 {
b();
c();
}
}

would use stack script or cris for a physic pen partten

gosoccerboy5 wrote:

Also, instead of

while (5 > n):
    n = n + 1

(or with curly brackets or whatever) shouldn't it be

repeat until (not (5 > n)):
    n = n + 1

(again, just assuming the syntax is indentation based)? Because that's how it is in Scratch?

Resince wrote:

Awesome idea, I've always wanted to make a programming language in Scratch that resembled the syntax of Javascript.

What I mean by this is:

var i = 0; // Creates a variable set to zero.
repeat (5) { // Repeat Loop
  i++; // Changes i by + 1
  say (i); // Prints i
}

gosoccerboy5 wrote:

mybearworld wrote:

repeat 20
me = Cat
}

Syntax error. Also, all you have to do is measure how many ‘loops’ you'd be in by counting the number of curly brackets, and subtracting the amount of }'s.

I'm torn between indentation and curly brackets - indentation might be more intuitive for Scratch users (concise syntax), but curly brackets might be easier for the parser(?) and would be easier to type in.

hello {
    world
}

Greg8128 wrote:

If the ‘{’ is missing, you could throw a compile error as gosoccerboy suggested. Alternatively, you could just take the next statement as the body of the loop, which allows stuff such as:

if (i > 3)
foo();
else
bar();

In fact, you could handle the case with the ‘{’ using this method by implementing the {…} as a ‘compound statement’, or several statements that the compiler treats as one. This approach also has several other cool advantages that I can discuss if you want.

Greg8128 wrote:

repeat 10
a();
repeat 5
b();
c();

would be read by the compiler as:

repeat 10 {
a();
repeat 5 {
b();
c();
}
}

mybearworld wrote:

Greg8128 wrote:

If the ‘{’ is missing, you could throw a compile error as gosoccerboy suggested. Alternatively, you could just take the next statement as the body of the loop, which allows stuff such as:
if (i > 3)
foo();
else
bar();

In fact, you could handle the case with the ‘{’ using this method by implementing the {…} as a ‘compound statement’, or several statements that the compiler treats as one. This approach also has several other cool advantages that I can discuss if you want.
I don't really understand what you mean with this part.

x = 5;
y = 7;

{
x = 5;
y = 7;
}

if (a)
b();
else
if ( c )
d();
else
e();

if ( c )
d();
else
e();

Greg8128 wrote:

Another syntax that you could consider using is s-expressions, which are used in languages such as lisp.

Here is an example of code in Lisp, a language which uses s-expressions:

(setq x 10)
(setq y (+ (* x 3) 20))

And the “equivalent” code in C:

int x = 10;
int y = x * 3 + 20;

Basically, s-expressions are enclosed in parentheses, and have arguments separated by spaces. The first argument is an operator or function, and the rest are arguments for that operator or function. For example, “(* 3 4 (+ 2 3))” in lisp is equivalent to “3 * 4 * (2+3)” in C.

S-expressions look weird, but they have the advantage of being easier to process with a computer. For example, you don't have to worry about order of operations, which can get rather complicated in other languages.

(* 5 4 6 (+ 7 9))

(5 * 4 * 6 * (7 + 9))

Greg8128 wrote:

(setq x 10)
(setq y (+ (* x 3) 20))

Greg8128 wrote:

To prove that parsing s-expressions is really easy, I made an s-expression parser in an hour or so:
https/cdn2.scratch.mit.edu/get_image/project/472621441_100x80.png
The whole thing, including demo driver code, is just 155 blocks.