World: r3wp
[Rebol School] Rebol School
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eFishAnt 4-Apr-2006 [102] | The part of Logo that works is turtle graphics in Draw. Students get quick results. So they experiement and learn. See Gregg's Logo talk...where REBOL needs more "turtles" |
[unknown: 9] 4-Apr-2006 [103] | It would be cool to build a sort of proto-tree. So you can see where in the tree a word is related. I created a graphic language that effectively had two commands: Draw: at an xy point and Circle: which had center coordinates, radius, angle and divisor. The angle and devisor allowed you to pull an interesting trick. So to make a square, you simply called it with a divisor of 4. this would build a string (block) with 4 pairs. If you wanted a diamond, set the angle to 45. You then passed the string to draw. This may seem like a weird way to do this, but it was perfect for a real time rending system that was interactive. We use this in a draw program like Flash. |
JaimeVargas 4-Apr-2006 [104x3] | Now another concept is that you can make those symbols designate any value at any time. So 1 + 1 == 2 or a: 1 a + 1 == 2 |
So symbols can take place for values, in standard funcs. | |
BTW, The interpreter transform the infix form into a prefix form: 1 + 1 is really + 1 1 | |
eFishAnt 4-Apr-2006 [107] | Anton, Josh and I are planning to visit KSU very soon, what a cooincidence...to teach them how to teach using Predictive CognitionTM. |
Anton 4-Apr-2006 [108] | Forward thinking , you mean ? |
[unknown: 9] 4-Apr-2006 [109] | I missed the KSU....is that Kansas, or Kennesaw?? |
eFishAnt 4-Apr-2006 [110] | Kansas State University. |
JaimeVargas 4-Apr-2006 [111] | Another concepts is that a symbos (kinow in rebol as a word) can have found different forms. |
denismx 4-Apr-2006 [112x2] | downloaded the text on denotational semantics, Anton. Interesting. |
keep on Jaime. Reading... | |
JaimeVargas 4-Apr-2006 [114] | MY-WORD is a symbol and get evualted to the value inmediately. |
Pekr 4-Apr-2006 [115] | interesting talk - why this group is not web-public? :-) |
Anton 4-Apr-2006 [116] | Yeah, it's great. I didn't know much about densem before. |
JaimeVargas 4-Apr-2006 [117x2] | MY-WORD: (notice the colon) is the what is used to bind a word (kind of a C assignment) |
:MY-WORD (notice the colon again) is the another way to access the value imagine it to be get the value, it is useful to get values that will cause evaulation like functions. | |
denismx 4-Apr-2006 [119] | Difference between symbol and variable: A symbol can be of any type and does not get declared. Period. Is that correct? |
JaimeVargas 4-Apr-2006 [120] | Correct. |
denismx 4-Apr-2006 [121x2] | :word word: Like pointers. |
Are they pointers? | |
JaimeVargas 4-Apr-2006 [123] | Rebol is strongly typed dynamic language. While C is strongly typed static language (types are declared). |
[unknown: 9] 4-Apr-2006 [124] | Note: I mentioned the Draw Circle thing, it may have seemed out of contect…but I was thinking about the fact that about two dozen commands were generated from just these two in terms of proto. |
JaimeVargas 4-Apr-2006 [125x2] | There are not pointers in Rebol they are not necessary. |
So all no pointer math here. | |
Anton 4-Apr-2006 [127] | I think Jaime is trying to speak more in the terminology you understand from other languages, but by "symbol" he really should say "word!". |
JaimeVargas 4-Apr-2006 [128] | The interpreter does the memory management for you. |
denismx 4-Apr-2006 [129x2] | Reichart, you are working on defining the paradigm of the language. I think that is the right direction to follow to generate a faster learning map of Rebol. |
No pointer math, like in Java. But maybe they are pointers anyway, of similar. | |
Anton 4-Apr-2006 [131] | Words usually automatically "decay" (in rebol terminology they "reduce") to their associated value (if they have one). |
denismx 4-Apr-2006 [132] | Ok, Anton, word is the word :-) |
JaimeVargas 4-Apr-2006 [133] | On last form is 'MY-WORD (Notice the single quote) it is a way to way to 'quote' a symbol this is useful when doing DATA as CODE. Another major concept in rebol. |
Anton 4-Apr-2006 [134] | If that value is a "hot" one (like a function!) then the get-word syntax (:word) will prevent the evaluation whilst still allowing you to get the value. |
denismx 4-Apr-2006 [135] | And the idea of a graph giving the family tree of the language is terrific. |
JaimeVargas 4-Apr-2006 [136] | That is in rebol the data remains data until it is interpreted. It is not transform into some bytecode or something else it is just data. |
eFishAnt 4-Apr-2006 [137] | you can always probe system |
denismx 4-Apr-2006 [138] | Yes Jaime, what you are explaining is indeed a fundamental concept in Rebol. And one that has to be mastered early. |
JaimeVargas 4-Apr-2006 [139x2] | denismx regarding the books I mention even though they are not about rebol. They introduce a lot fo the concepts of Rebol. |
Rebol is a decendant of Lisp the first functional programming language. So understanding this it will help you get the gist of rebol. | |
denismx 4-Apr-2006 [141x2] | I see. Hum... but that would add up another language to the too many I have in my head now :-) |
I'm starting to mix them up sometimes. Not good in class! :-)) | |
Anton 4-Apr-2006 [143] | Yes, if we have a word set to a value like this: word: 123 then there is a series of possible "reductions" possible: 'word -> word -> 123 Likewise for a function: word: func [][print "hello"] The reductions: 'word -> :word (gives unevaluated function) -> word (evaluates the function to print "hello") |
eFishAnt 4-Apr-2006 [144] | >> source send ;you can get the source code of a function by using the source command. Documentation is built-in. |
[unknown: 9] 4-Apr-2006 [145] | One very small but interesting thing about Rebol that makes it different than almost 20 languages I can think of………..that is that it helps to learn Rebol like you would a spoken language in sentences, not words. |
JaimeVargas 4-Apr-2006 [146] | An alternative is to learn denotational semantics, or lambda calculi, but this is only useful to CS major trying to proof properties of a language, it doesn't help build the intuitions of the language. But I will not discourage to go that route if you please. |
denismx 4-Apr-2006 [147] | I start writing code in C while talking, and suddenly I'm writin Pascal... !!! |
[unknown: 9] 4-Apr-2006 [148] | Yup! |
Pekr 4-Apr-2006 [149] | :-) |
Anton 4-Apr-2006 [150] | Oh man, have you ever done any web development ? |
[unknown: 9] 4-Apr-2006 [151] | LOL |
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