World: r3wp
[Rebol School] Rebol School
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Henrik 28-May-2007 [402] | I wish he would use shorter paragraphs. |
denismx 7-Jun-2007 [403] | Reichart: I'm surprised the tools you are wishing for in order to start holding online classes aren't already build in Rebol... From what I've seen, all the bits and pieces seem to be there already, maybe except for a whiteboard. No? |
[unknown: 9] 7-Jun-2007 [404] | Rebol is a language... |
denismx 9-Jun-2007 [405] | Well I did'nt mean "built-in" in Rebol, but built using Rebol, of course. |
Geomol 22-Jun-2007 [406] | To everyone: What characterize a good learning book? Do you prefer thick books with deep explanation and many examples, or do you prefer the thin book with the essentials? Look at your collection of technical book; about computer languages, OSs, databases or what you have. Which ones do you like, and which ones is no-good? |
Graham 22-Jun-2007 [407x2] | the bigger the better |
and preferably with water proof pages so I can read it in the bath :) | |
Geomol 22-Jun-2007 [409] | lol, you're special! |
Gregg 22-Jun-2007 [410] | I have some big books I like, but my favorites tend to be smaller. I love Jon Bentley's books, and anything by Robert Glass (almost wrote Philip Glass there :-), Kernighan, and DeMarco and Lister are other favorites. |
Graham 22-Jun-2007 [411x3] | I actually bought some HP tough paper for this purpose. It's water proof and and can be printed upon with laser printers. |
and very expensive | |
So, I can debug my programs in the bath :) | |
Geomol 22-Jun-2007 [414] | :-D |
PatrickP61 25-Jun-2007 [415x2] | Hi everyone, |
I'm a newbie and wanted to ask this question on a simple rebol program. If I have a variable COUNT and I wanted to write this value with a literal could I do this: write OutFile [Count " Total lines"]/append. But the word Count is not evaluated and I get "Count Total lines" instead of "8 Total lines". What do I need to tell rebol to return the value of COUNT? | |
Rebolek 25-Jun-2007 [417] | hi Patrik, try this: write OutFile reduce [Count " Total lines"] |
PatrickP61 25-Jun-2007 [418] | Rebolek - Does the word REDUCE evaluate all values in the block? |
Rebolek 25-Jun-2007 [419] | yes |
PatrickP61 25-Jun-2007 [420] | Thank you -- I'll try it |
Rebolek 25-Jun-2007 [421x2] | If you do not want to evaluate everything, use compose: compose [(count) " Total lines"] |
then only values in parens get evaluated | |
PatrickP61 25-Jun-2007 [423] | Works -- Thank you |
Geomol 25-Jun-2007 [424] | A suggestion: Many words in REBOL can do more than one thing, sometimes depending on data-type of the argument or the use of refinements. It's almost impossible to remember it all. So as a new one to the language, check the help for the new words, you're learning. Like >> ? reduce >> ? compose |
PatrickP61 25-Jun-2007 [425] | As a newbie, what suggestions do you have for me to debug my rebol scripts. For example, I have a script called "Convert_to_Table" that I am just starting to write. I can execute it -stand alone- and see the results of the run, but what I would like to do is be able to see what the console has for any values. In other words, when I double click the "Convert_to_Table" I can see the results but not ask the console questions like print Count or the like. How do you suggest a newbie debug a script? Should I go into console first and then perform a "do Convert_to_Table" and then be able to ask questions of console, or is there another way?. |
Geomol 25-Jun-2007 [426x3] | Yes, use the console! Also use PROBE in the script to check values. You can put PROBE in anywhere, also in the middle of a sequnce of words. |
Use some time to really understand probe. I use it all the time. | |
Carl write about the console here: http://www.rebol.com/docs/quick-start4.html | |
PatrickP61 25-Jun-2007 [429] | I will check it out |
Volker 25-Jun-2007 [430] | I rarely type into the console and probe everywhere in the code. there is also '??, which shows the name of the word too. |
PatrickP61 25-Jun-2007 [431] | Hi Volker, after a few variations, I used this: print reduce ["var-name= " var-name] What is the syntax for '?? |
Rebolek 25-Jun-2007 [432] | ?? - it's same as with probe: >> ?? probe probe: func [ {Prints a molded, unevaluated value and returns the same value.} value ][ print mold :value :value ] |
PatrickP61 25-Jun-2007 [433] | Ohhh I like the ?? var-name better! |
Rebolek 25-Jun-2007 [434x3] | Sorry, I meant ?? works same as ?, not probe |
hte advantage of probe is that you can insert it anywhere in your code | |
it prints value to console and returns that value | |
Volker 25-Jun-2007 [437] | thats true with ?? too (as long as you dump vars) thats the advantage over ? |
Rebolek 25-Jun-2007 [438x3] | you have for example your code: append head copy/part trim string ln "something" and to easy understand what's going on, you can put 'probe after 'append, 'head, 'copy/part and 'trim to see how the evaluation is going on. |
Volker: no, ?? gets 'value and probe gets value as input, so they return something different. | |
probe evaluates, while?? not. | |
Volker 25-Jun-2007 [441] | but you can put both in the expression |
PatrickP61 25-Jun-2007 [442] | Ok to sum up: Probe will return only the value to console, ? will return the variable along with short text and value, and ?? will return var name with value |
Volker 25-Jun-2007 [443x2] | append head copy/part trim ?? string ?? ln "something" ; works |
?? does a get, you can put it in expressions before variables | |
Rebolek 25-Jun-2007 [445] | Volker: no, ?? changes the meaning of expression in case you put it before function: >> f: func [a][a] >> a: 1 == 1 >> b: probe f a 1 == 1 >> type? :b == integer! >> b: ?? f a f: func [a][a] == 1 >> type? :b == function! |
PatrickP61 25-Jun-2007 [446x2] | Wow, I guess there are a lot of ways to "explain" how rebol is evaluating an expression. Thank you. I will try them all sometime. |
P.S. In AltMe, what do you guys type to get a carriage return without sending the AltMe message until you do an <enter> | |
Rebolek 25-Jun-2007 [448] | It's the "pen" icon, press it and you can send messages with CTRL+S |
PatrickP61 25-Jun-2007 [449] | This is a test This is a test OK It works! |
Anton 25-Jun-2007 [450] | If you hover over the icons, you see the help info text at top left. |
Volker 25-Jun-2007 [451] | Rebolek, i said all the time "with variables". Of course it does not know what you use as function and what as variable |
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