OpenEuphoria

1. Live Tutoria?

• Posted by "Lynn Kilroy" <leks_transportation at hotmail.com> Jan 19, 2006
• 524 views

Okies.  You guys all gave me great advice, so I think I will ask for little=

code snippets to make mine own include file.  I can examine your snippets t=
o
better understand the syntax of the language, and I can ask questions about=

various snippets.  I know you all already told me about the Inkey Function,=

but some idiot I've never met decided it was a good idea to delete those=

messages without putting the code you guys all slaved over and over again o=
n
before she could copy it to Euphoria.  So, I'm going to need it again.

Along with the little code snippets, I think I will ask questions and stuff=

about the little snippets so I can understand each one.  I will, as I learn=

the syntax of the language, take cracks at code snippets myself, and post=

them here to see if I'm beginning to get the hang of things.  I write in=

QBasic, which isn't case sensative, so this case sensativity thing is new t=
o
me.  That said, I was told I have very Pascal conventions in coding, and=

that I *do* use Caps consistently.

If I lost anyone, please let me know. {Blushes}

So, if we may, I would like to begin with the Inkey function.  INKEY$ just=

reads a key from the keyboard buffer.  It does not wait for a user to press=

a key.  Since all my programs use this funtion, and since I'm used to using=

it, I would like to begin by building a whole new library with this.  I
guess I would call the file 'Inkey.E,' and and it would be dedicated to all=

the functions that read a key from the keyboard buffer.  I will later take=

cracks at keyboard filter input subroutines, but I think I would include=

that in my ColorLocate include file {'ClrLcate.E?'}.  If there is nothing i=
n
the keyboard buffer, INKEY$ returns a nul string {""}, but I would need to=

know the Euphoria equivilant of this.  You already told me, but I am clearl=
y
too lazy to look in the archives.

So ... to begin with, how would the Include File be formatted?  And how
would the call be made?  There would be no need to pass an argument to
function Inkey, as it only returns results: A key from the keyboard buffer.=


>function Inkey
>?
>end function

Please help me with the syntax and stuff for the Inkey.E include file.
{Smiles}

Love & Friendship & Blessed Be!
Lynn Erika Kilroy

3. Re: Live Tutoria?

• Posted by don cole <doncole at pacbell.net> Jan 19, 2006
• 521 views

Lynn Kilroy wrote:
> 
> Okies.  You guys all gave me great advice, so I think I will ask for little=
> 
> code snippets to make mine own include file.  I can examine your snippets t=
> o
> better understand the syntax of the language, and I can ask questions about=
> 
> various snippets.  I know you all already told me about the Inkey Function,=
> 
> but some idiot I've never met decided it was a good idea to delete those=
> 
> messages without putting the code you guys all slaved over and over again o=
> n
> before she could copy it to Euphoria.  So, I'm going to need it again.
> 
> Along with the little code snippets, I think I will ask questions and stuff=
> 
> about the little snippets so I can understand each one.  I will, as I learn=
> 
> the syntax of the language, take cracks at code snippets myself, and post=
> 
> them here to see if I'm beginning to get the hang of things.  I write in=
> 
> QBasic, which isn't case sensative, so this case sensativity thing is new t=
> o
> me.  That said, I was told I have very Pascal conventions in coding, and=
> 
> that I *do* use Caps consistently.
> 
> If I lost anyone, please let me know. {Blushes}
> 
> So, if we may, I would like to begin with the Inkey function.  INKEY$ just=
> 
> reads a key from the keyboard buffer.  It does not wait for a user to press=
> 
> a key. 


-----------------------------------------------------------------
  I'm confused here, how could any keys be in the keyboard buffer if no keys
have been pressed?

-----------------------------------------------------------------
 >Since all my programs use this funtion, and since I'm used to using=
> 
> it, I would like to begin by building a whole new library with this.  I
> guess I would call the file 'Inkey.E,' and and it would be dedicated to all=
> 

I would suggest inkey.e although Inkey.E would problely work. I'm not sure 
about the capital E.
> the functions that read a key from the keyboard buffer.  I will later take=
> 
> cracks at keyboard filter input subroutines, but I think I would include=
> 
> that in my ColorLocate include file {'ClrLcate.E?'}.  If there is nothing i=
> n
> the keyboard buffer, INKEY$ returns a nul string {""}, but I would need to=
> 
   Again why would you care what's in the keyboard buffer if no key has been
 pressed.
   If you are just looking for a place to temparly store stuff use the variable
 temp.
 object temp
or
sequence temp
or
atom temp

depending on what you are expecting to be in temp.

Another way would be to use acquire. (forget that for now)


> know the Euphoria equivilant of this.  You already told me, but I am clearl=
> y
> too lazy to look in the archives.
> 
> So ... to begin with, how would the Include File be formatted?  And how
> would the call be made?  There would be no need to pass an argument to
> function Inkey, as it only returns results: A key from the keyboard buffer.=
> 
> 

> 
> 


To get one key at a time:

integer a
sequnce b
a=wait_key()


Read up on getc() and gets()


To get a string from the keyboard:

function get_string()
  sequence words
  integer a
   words=""
   a=wait_key()
   if a=13 then--Enter
    return words
   end if
   words=words & sprintf("%s",a)
end function

------------------------run this program-----------

-ascii.ex find the ascii code of a keystrpoke

include get.e include graphics.e

integer key

while 1 =1 do text_color(BRIGHT_BLUE) puts(1,"[F1](315)to Exit ") puts(1,"< Hit Any Key >")

key = wait_key() if key=315 then exit end if text_color(WHITE) printf(1,"\nprintf sequence=%s",{key}) printf(1,"\nprintf decimal=%d\n",{key}) printf(1,"ascii=%d\n",{key}) printf(1,"euphoria expresion=%d\n",{key}) end while

------------end of program-------------- Don Cole A Bug is an un-documented feature. A Feature is a documented Bug. }}}

5. Re: Live Tutoria?

• Posted by "Lynn Kilroy" <leks_transportation at hotmail.com> Jan 20, 2006
• 508 views

>
>-- [Declared in file Inkey.e]
>global function Inkey()
>     return get_key()
>end function
>
>then in some other code after you include the file and you can use Inkey() 
>freely.
>
>include Inkey.e
>
>integer char
>char = 0
>
>-- Print the pressed key until Q is hit
>while char != 'q' do
>     char = Inkey()
>     ? char
>end while
>
>

So I can conclude the following:

Prekey is used to clear the keyboard buffer.  This can probably be a 
procedure, as it returns nothing of value to the main program.  I will take 
a guess at how it will be coded based on what you have sent me.

>global procedure Prekey()
>while Inkey()>-1
>wend
>end procedure

Would this be the accurate way to format this for use in the Inkey.e file?

Love & Friendship & Blessed Be!
Lynn Erika Kilroy

7. Re: Live Tutoria?

• Posted by don cole <doncole at pacbell.net> Jan 20, 2006
• 498 views

Lynn Kilroy wrote:
> 
> >To get one key at a time:
> >
> >integer a
> >sequnce b
> >a=wait_key()
> >
> >
> >Read up on getc() and gets()
> >
> >
> >To get a string from the keyboard:
> >
> >function get_string()
> >   sequence words
> >   integer a
> >    words=""
> >    a=wait_key()
> >    if a=13 then--Enter
> >     return words
> >    end if
> >    words=words & sprintf("%s",a)
> >end function
> >
> >------------------------run this program-----------
> >}}}
<eucode>
> >
> >---ascii.ex find the ascii code of a keystrpoke
> >
> >include get.e
> >include graphics.e
> >
> >integer key
> >
> >while 1 =1 do
> >   text_color(BRIGHT_BLUE)
> >  puts(1,"[F1](315)to Exit  ")
> >  puts(1,"< Hit Any Key >")
> >
> >     key = wait_key()
> >    if key=315 then
> >        exit
> >    end if
> >  text_color(WHITE)
> >   printf(1,"\nprintf sequence=%s",{key})
> >   printf(1,"\nprintf decimal=%d\n",{key})
> >   printf(1,"ascii=%d\n",{key})
> >   printf(1,"euphoria expresion=%d\n",{key})
> >end while
> >
> >--------------end of program-------------------
> >Don Cole
> 
> Ummmm ....  Very helpful ....  But it kind of reminds me of Greek, and is=
> =20
> about as understandable to me, which means it's of little use to me.  Which=
> =20
> is why I'm working with little code snippets for the time being.  The idea=
> =20
> is that sooner or later, I will learn all kinds of neat things that will=
> =20
> allow me to write more efficient code.  Also, I will build a library of=20
> subroutines and functions {okay, for those dedicated to C, ***PROCEDURES***=
> =20
> and functions} that more conform to my standard libraries that I use.  But,=
> =20
> since you're planning on being so useful, perhaps you can help me with a=
> =20
> little bit of code I'm dabbling with?  Just for starters?  Since I can't=
> =20
> complete an actual program until all subroutines are complete {or at least=
> =20
> enough to say so} and I understand enough of the Euphoria Statements to be=
> =20
> able to get it to do at least something close to what I want.
> 
> This program is supposed to print keypresses from the keyboard. 

That's exactly what the program I sent you above does?
Run it and press ESC.

> But it=20
> crashes.  "Variable Key has not been assigned a value."  What is the causin=
> g=20
> the error, please?  And how do I assign Key a value?
> 
> Love & Friendship & Blessed Be!
> Lynn Erika Kilroy
> 
> Learning.ex
> =========================
> =========================
> =============
> include ..\..\include\Inkey.e
> 
> integer Key
> 
> Prekey()
> 
> 
> while Key != 27 do
> 
> Key = Inkey()
> 
> ? Inkey()
> 
> end while
> =========================
> =========================
> =============
> 
> Inkey.e
> =========================
> =========================
> =============
> global function Inkey()
> return get_key()
> end function
> 
> global procedure Prekey()
> while Inkey() > -1 do
> end while
> end procedure

I'll work on your error and get back to you.

Don Cole
 A Bug is an un-documented feature.
A Feature is a documented Bug.

9. Re: Live Tutoria?

• Posted by Jason Gade <jaygade at yahoo.com> Jan 20, 2006
• 614 views

Lynn Kilroy wrote:

<snip>

> Which=
> 
> is why I'm working with little code snippets for the time being.  The idea=
> 
> is that sooner or later, I will learn all kinds of neat things that will=
> 
> allow me to write more efficient code.  Also, I will build a library of
> subroutines and functions {okay, for those dedicated to C, ***PROCEDURES***=
> 
> and functions} that more conform to my standard libraries that I use.  But,=
> 
> since you're planning on being so useful, perhaps you can help me with a=
> 
> little bit of code I'm dabbling with?  Just for starters?  Since I can't=
> 
> complete an actual program until all subroutines are complete {or at least=
> 
> enough to say so} and I understand enough of the Euphoria Statements to be=
> 
> able to get it to do at least something close to what I want.
> 
> This program is supposed to print keypresses from the keyboard.  But it
> crashes.  "Variable Key has not been assigned a value."  What is the causin=
> g=20
> the error, please?  And how do I assign Key a value?
> 
> Love & Friendship & Blessed Be!
> Lynn Erika Kilroy
> 
> Learning.ex
> =========================
> =========================
> =============
> include ..\..\include\Inkey.e
> 
> integer Key
> 
> Prekey()
> 
> 
> while Key != 27 do
> 
> Key = Inkey()
> 
> ? Inkey()
> 
> end while
> =========================
> =========================
> =============
> 
> Inkey.e
> =========================
> =========================
> =============
> global function Inkey()
> return get_key()
> end function
> 
> global procedure Prekey()
> while Inkey() > -1 do
> end while
> end procedure
> =========================
> =========================
> =============
> 
> 
> Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
> 
> 
Okay, the line in your program
while Key != 27 do
is the problem. Before that, you have declared Key but not yet assigned it a
value. All variables must be assigned a value before they are compared or added 1
to or whatever.

So before your loop you must say
Key = 0
or
Key = Inkey()

So here is your code (untested, but should work)

include ..\..\include\Inkey.e
 
integer Key
Key = 0 -- could put this on the same line if you wanted to, like this:
-- integer Key Key = 0

 
Prekey()
 

while Key != 27 do
 
Key = Inkey()
 
? Inkey()
 
end while

Instead of assigning 0 to Key, you could put an initial condition right before
your loop, as follows:

Key = Inkey() -- initial status of variable
while Key != 27 do
 
Key = Inkey()
 
? Inkey()
 
end while

--
"The author regrets that he is unable to reconcile himself to the
thoughtful point of view you have expressed. However, it must be kept
in mind that being raised in different cultures and different places can
result in such differences of viewpoint between individuals.
The author is from planet Earth." [author unknown]

j.

11. Re: Live Tutoria?

• Posted by "Lynn Kilroy" <leks_transportation at hotmail.com> Jan 21, 2006
• 504 views

>
>That's exactly what the program I sent you above does?
>Run it and press ESC.
>
> > But it=20
> > crashes.  "Variable Key has not been assigned a value."  What is the=

>causin=
> > g=20
> > the error, please?  And how do I assign Key a value?
> >
> > Love & Friendship & Blessed Be!
> > Lynn Erika Kilroy
> >
> > Learning.ex
> > ========================
==
> > ========================
==
> > =============
> > include ..\..\include\Inkey.e
> >
> > integer Key
> >
> > Prekey()
> >
> >
> > while Key != 27 do
> >
> > Key = Inkey()
> >
> > ? Inkey()
> >
> > end while
> > ========================
==
> > ========================
==
> > =============
> >
> > Inkey.e
> > ========================
==
> > ========================
==
> > =============
> > global function Inkey()
> > return get_key()
> > end function
> >
> > global procedure Prekey()
> > while Inkey() > -1 do
> > end while
> > end procedure
>
>I'll work on your error and get back to you.
>

If I use your code, then I've learned nothing about how Euphoria works.  If=

you send me code that I can play with that's simple and allows me to draw=

conclusions about how the statements and variables all work together, then =
I
will learn how the language works.

My efforts are to learn to write the code by putting together assorted
smaller subroutines {procedures} and then making larger and more complicate=
d
ones.  If a program fails to operate, then we can discuss what it is that=

I'm trying to do and how I am trying to go about it so I can see what it is=

that I'm doing wrong, so as not to repeat the mistake in the future.

I tend to use a standard set of functions and subs {procedures}.  It would=

be best to recreate clones of these and use them in Euphoria for two
reasons.  The first is that these subs and functions will more closely
resemble what I'm used to using, and the second is that through the process=

of creating these subs and functions, I would learn more about Euphoria and=

have a better understanding how to use the language.

The first function, Inkey(), is written.  But I do not know truly if it
works yet.  It is intended to read a key from the keyboard buffer and retur=
n
the result to the calling program, and is also intended to be kept in an=

include file so I can add it without having to retype it over and over and=

over again.  The second part, a procedure, is Prekey.  It calls Inkey until=

Inkey returns nothing {and seems to work}.  This is done to clear the
keyboard buffer, as it has been my experience this is often necessary.

The main program is setup as follows: Include Inkey.e file, with Inkey and=

Prekey.  Define Key as an integer.  The definition goes well.  While Key !=
=
27 do, also executes.  Key = Inkey(), then ? Key.  At ? Key, it says
Variable Key is unassigned.  The theory is it will print Key on each pass.=
=20=20
This is just a test routine, so I don't care if it messes up the display.  =
I
want to know that this, my first Euphoria program, works right.  It isn't.=
=20=20
So I will include the program and it's include file again.


The Program Learning.Ex:
==================
>include ..\..\include\Inkey.e
>
>integer Key
>
>Prekey()
>
>
>while Key != 27 do
>
>Key = Inkey()
>
>? Inkey()
>
>end while
==================
End Program File Learning.Ex

The Include File Inkey.e
===============
>global function Inkey()
>return get_key()
>end function
>
>global procedure Prekey()
>while Inkey() > -1 do
>end while
>end procedure
===============
End Include File Inkey.e

The error is:
========
>D:\LEKSSOFT\EUPHORIA\SOURCE\LEARNING\LEARNING.EX:8
>variable Key has not been assigned a value
>--> see ex.err
========
End Error

Begin Ex.Err
========
>D:\LEKSSOFT\EUPHORIA\SOURCE\LEARNING\LEARNING.EX:8
>variable Key has not been assigned a value
>
>
>Global & Local Variables
>
>D:\LEKSSOFT\EUPHORIA\SOURCE\LEARNING\LEARNING.EX:
>    Key = <no value>
========
End Ex.Err

Please help me understand what is causing this error and how I can fix this=

part of my program.  It is a pretty basic program, but one has to start
somewhere. {Smiles}

Thank you very much!

Love & Friendship & Blessed Be!
Lynn Erika Kilroy

-New Users Make Basic Errors.  But to ***REALLY*** screw things up, that=

takes an experienced user!

13. Re: Live Tutoria?

• Posted by Jason Gade <jaygade at yahoo.com> Jan 21, 2006
• 494 views

Lynn Kilroy wrote:
> 
> >Okay, the line in your program
> >while Key != 27 do
> >is the problem. Before that, you have declared Key but not yet assigned it=
> 
> >a value. All variables must be assigned a value before they are compared o=
> r
> >added 1 to or whatever.
> >
> >So before your loop you must say
> >Key = 0
> >or
> >Key = Inkey()
> >
> >So here is your code (untested, but should work)
> >
> >}}}
<eucode>
> >include ..\..\include\Inkey.e
> >
> >integer Key
> >Key = 0 -- could put this on the same line if you wanted to, like this:
> >-- integer Key Key = 0
> >
> >
> >Prekey()
> >
> >
> >while Key != 27 do
> >
> >Key = Inkey()
> >
> >? Inkey()
> >
> >end while
> ></eucode>
{{{

> >
> >Instead of assigning 0 to Key, you could put an initial condition right=
> 
> >before your loop, as follows:
> >
> >}}}
<eucode>
> >Key = Inkey() -- initial status of variable
> >while Key != 27 do
> >
> >Key = Inkey()
> >
> >? Inkey()
> >
> >end while
> ></eucode>
{{{

> 
> Thank you!  I reformatted the query and reposted it.  But since you've
> answered the question, I guess we can just ignore the other one. {Giggles}=
> 
> Or I'm more likely to get more and more replies. {Laughs}
> 
> So it is a pretty simple concept.
> 
> 1. Declare the variable.
> 2. Assign the variable a value.
> 3. Use the variable.
> 
> That's a little different from QB.  In QB, you define it and it had an
> default assigned value.  I will remember that.
> 
> I will not put a second statement on the same line, and all my
> initialization code will always be placed before the first sub {procedure}=
> 
> or function call. {Smiles} The program returned nothing but -1's all the wa=
> y
> up the screen.  That's a start.
> 
> With this information, I cleared up the bug, and I added Waitkey.  This
> completes the Inkey.e Include file.  Here is the final program to this
> point.
> 
> Begin Learning.Ex
> ===========
> include ..\..\include\Inkey.e
> 
> integer Key
> 
> Key = 0
> 
> Prekey()
> 
> while Key != 27 do
> 
> Key = Waitkey()
> 
> ? Key
> 
> end while
> ==========
> End Learning.Ex
> 
> Begin Inkey.e
> ==========
> global function Inkey()
> return get_key()
> end function
> 
> global procedure Prekey()
> while Inkey() > -1 do
> end while
> end procedure
> 
> global function Waitkey()
> 
> integer Key
> 
> Key = -1
> 
> while Key = -1 do
>   Key = Inkey()
> end while
> 
> return Key
> 
> end function
<snip>

Try this (tested code):

include get.e
include graphics.e

procedure ColorLocatePrintTextOnly(integer FGC,
				   integer BGC,
				   integer Row,
				   integer Col,
				   sequence Text)

    text_color(FGC)
    bk_color(BGC)
    position(Row, Col)
    puts(1, Text)

    text_color(WHITE)
    bk_color(BLACK)
    
    
end procedure

object Key

clear_screen()

ColorLocatePrintTextOnly(RED, BROWN, 12, 34, "Hello, World!")

Key = wait_key()

Let me know if you have any more questions.

Oh, I don't know if you are using email or the web interface for EUforum. If you
are using the web interface, you can put \<eucode\> \</eucode\> around a code
snippet to "colorize" it in the forum.

I don't know if that will come out right (we need a preview in the webforum,
please!) but if not, here it is in english:

(less-than-symbol)eucode(greater-than-symbol)
--code--
(less-than-symbol)/eucode(greater-than-symbol)

--
"The author regrets that he is unable to reconcile himself to the
thoughtful point of view you have expressed. However, it must be kept
in mind that being raised in different cultures and different places can
result in such differences of viewpoint between individuals.
The author is from planet Earth." [author unknown]

j.

15. Re: Live Tutoria?

• Posted by Jason Gade <jaygade at yahoo.com> Jan 21, 2006
• 514 views

Craig Welch wrote:
> Lynn Kilroy wrote:
> >Okies.  You guys all gave me great advice,
> >so I think I will ask for little
> >code snippets to make mine own include file.
> 
> key.ex in euphoria\bin will show you keycodes, as well as how to read from the
> keyboard.
> 
> I strongly recommend that you run 'rundemos.exw' shortly after, it's the best
> learning tool around. And code snippets everywhere.
> 
> -- 
> Craig

BTW, rundemos.exw is with win32lib

Also, Lynn, with regards to your Inkey program you should use puts() instead of
? or print(). print() and ? print sequences as numbers whereas puts() prints
sequences as strings.

I won't explain printf() here (read the docs) but it is pretty flexible for
printing out different data types.

Euphoria doesn't have a built-in procedure like BASIC's PRINT that determines
the type of a variable automatically and prints it out accordingly. You have to
specifiy it like in C.

--
"The author regrets that he is unable to reconcile himself to the
thoughtful point of view you have expressed. However, it must be kept
in mind that being raised in different cultures and different places can
result in such differences of viewpoint between individuals.
The author is from planet Earth." [author unknown]

j.