Introducing Cologo, a collaborative web-based Logo

Greetings Logo enthusiasts -

I'm pleased to announce the first release of Cologo, a collaborative
web-based Logo environment based on Google Spreadsheets and Google
Gadgets:

http://www.cologo-lang.org/

The front page has a live demo and a feature summary. From there,
check out the Getting Started guide:
http://www.cologo-lang.org/docs_starting.html

Firefox or Safari are recommended. Internet Explorer doesn't support
turtle graphics and still has a couple of other bugs. The gadget
works with Opera, but unfortunately Google Spreadsheets does not.

Cologo programs are written in Google Spreadsheets using a grid
layout. Multiple people can edit the the program over the web
simultaneously, and can chat in real time with other collaborators.
The grid layout allows for procedures to be arranged horizontally as
well as vertically, and for code, data and documentation to appear on
the same sheet. Cell formatting is supported, so code can be
highlighted with color and fonts without affecting how the program
works.

The Cologo environment is a "gadget," typically installed on the
spreadsheet that contains the code. The Cologo gadget recognizes
changes to the code in real time. The gadget for a program can also be
installed on a web page or in any gadget container (iGoogle, MySpace,
Orkut). The interpreter is implemented in JavaScript, and runs
entirely in the web browser.

The Cologo language is based on Berkeley Logo. This initial version is
a useful subset of Berkeley Logo, and it's a continuing goal to
broaden its support, with only minor differences in syntax. The most
notable difference for beginners right now is the lack of infix
operators: Instead of "3 * 4 + 5", say "sum product 3 4 5". And the
procedure definition syntax is different, using the grid layout of the
spreadsheet. Most Berkeley Logo 5.5 primitives have been implemented.

The main goal of this initial version of Cologo is to validate the
concepts of editing Logo programs in a spreadsheet, and of
collaborating on a program using Google Spreadsheets. I'm interested
in feedback on these aspects of the user experience at this stage.

Goals for future versions include:
* better "stop" support for interrupting infinite loops
* visible turtle
* support for a greater subset of Berkeley Logo, especially arrays,
templates and macros
* richer graphics primitives
* primitives for user interaction
* primitives for creating and modifying spreadsheets, including the
program's own code
* primitives for accessing data and services over the Internet from
the browser
* improve Internet Explorer support
* improve speed and memory efficiency

Please give it a try, and let me know what you think!

Thanks!
-- Dan

What an interesting idea!

This is the first time I've been even slightly tempted to abandon my resolve
not to let Google know anything about me (and, yes, I know it's a losing
battle). I'm not, so far at least, tempted /enough/, though. :-) Don't
take it personally.

One little quibble: Logo orthodoxy is that "primitive" is an adjective, not
a noun; there are primitive procedures and user-defined procedures. (In
UCBLogo there's an intermediate case, library procedures, which come with
Logo and load automatically, but are written in Logo.) We sometimes speak
loosely and use "primitives" to mean "primitive procedures," but it's always
deemed best to avoid phrases such as "primitives and procedures." The point
is that we want kids to think of the procedures they write as being /just as
good/ as the ones built in. More specifically, it takes some bending over
backwards to convince (many) kids that they can use procedures they wrote in
defining further procedures.

P.S. You have backquote (`) in the list of missing UCBLogo features, but
it's a library procedure, and doesn't even depend on backslash escapes or
anything, so you could remove it from that list if you instead add having
a Logo library!

On Aug 2, 7:20*pm, b...@cs.berkeley.edu (Brian Harvey) wrote:
> What an interesting idea!
>
> This is the first time I've been even slightly tempted to abandon my resolve
> not to let Google know anything about me (and, yes, I know it's a losing
> battle). *I'm not, so far at least, tempted /enough/, though. *:-) *Don't
> take it personally.

No problem. Technically, the Cologo gadget can use any data source
that supports the Google Visualization API. Right now the only such
source I know is Google Spreadsheets, and of course it's Spreadsheets
that provides the real-time collaboration, edit-in-a-browser, sharing
and remote storage features. But any tabular data source would work
with the gadget. I have tests that simply create Cologo programs in
JavaScript arrays, no spreadsheet necessary.

The main goal of this early version is to prove the concepts of
editing and collaborating in spreadsheets. If it turns out another
direction would be more fruitful, it wouldn't be difficult to adapt
Cologo to use a more traditional layout with a web-based text editor.
It is rather nice that Google Spreadsheets is doing most of the heavy
lifting, though.

> One little quibble: Logo orthodoxy is that "primitive" is an adjective, not
> a noun; there are primitive procedures and user-defined procedures. *(In
> UCBLogo there's an intermediate case, library procedures, which come with
> Logo and load automatically, but are written in Logo.) *We sometimes speak
> loosely and use "primitives" to mean "primitive procedures," but it's always
> deemed best to avoid phrases such as "primitives and procedures." *The point
> is that we want kids to think of the procedures they write as being /justas
> good/ as the ones built in. *More specifically, it takes some bending over
> backwards to convince (many) kids that they can use procedures they wrotein
> defining further procedures.
>
> P.S. *You have backquote (`) in the list of missing UCBLogo features, but
> it's a library procedure, and doesn't even depend on backslash escapes or
> anything, so you could remove it from that list if you instead add having
> a Logo library!

Thanks! There's plenty of time to adjust the terminology, and I'll be
happy to do so.

I'm new to Logo and the Logo community, and I don't have ready access
to classrooms full of kids to play with, so I'll be relying on
feedback from the community and from teachers to figure out how to
make Cologo useful and integrate it with existing Logo materials and
traditions. Early goals are to support your Computer Science Logo
Style series and Abelson and diSessa's Turtle Geometry. I greatly
appreciate all the feedback I've gotten so far. Keep it coming!

Thanks again!

-- Dan

Last evening, running Cologo in the Mozilla-based browser SeaMonkey
1.1.10 caused the focus of the cursor in text fields in Yahoo! Notepad
to stray randomly out of the text fields during text input, making
text input very difficult. The problem disappeared when I closed the
window with Cologo.

I upgraded to SeaMonkey 1.1.11 today, and have not been able to
reproduce this problem. Perhaps it had to do with some
incompatibility between 1.1.10 and Cologo.

If I run into this problem again, I'll report it in this thread.

-- Benjamin L. Russell