input languages - Page 14

Programming languages with a Lisp-like syntax extension mechanism

- by Giorgio

I have only a limited knowledge of Lisp (trying to learn a bit in my free time) but as far as I understand Lisp macros allow to introduce new language constructs and syntax by describing them in Lisp itself. This means that a new construct can be added as a library, without changing the Lisp compiler / interpreter. This approach is very different from that of other programming languages. E.g., if I wanted to extend Pascal with a new kind of loop or some particular idiom I would have to extend the syntax and semantics of the language and then implement that new feature in the compiler. Are there other programming languages outside the Lisp family (i.e. apart from Common Lisp, Scheme, Clojure (?), Racket (?), etc) that offer a similar possibility to extend the language within the language itself? EDIT Please, avoid extended discussion and be specific in your answers. Instead of a long list of programming languages that can be extended in some way or another, I would like to understand from a conceptual point of view what is specific to Lisp macros as an extension mechanism, and which non-Lisp programming languages offer some concept that is close to them.

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JavaScript: input validation in the keydown event

- by c411

Hi, I'm attempting to do info validation against user text input in the process of keydown event. The reason that I am trying to validate in the keydown event is because I do not want to display the characters those that are considered to be illegal in the input box at the beginning. The validation I am writing is like this, function validateUserInput(){ var code = this.event.keyCode; if ((code<48||code>57) // numerical &&code!==46 //delete &&code!==8 //back space &&code!==37 // <- arrow &&code!==39) // -> arrow { this.event.preventDefault(); } } I can keep going like this, however I am seeing drawbacks on this implmentation. Those are, for example, Conditional statement become longer and longer when I put more conditions to be examined. keyCodes can be different by browsers. I have to not only check what is not legal but also have to check what are exceptionals. In above examples, delete,backspace, and arrow keys are exceptionals. But the feature that I don't want to lose is having not to display the input in the textarea unless it passes the validation. (In case the user try to put illegal characters in the textarea, nothing should appear at all) That is why I am not doing validation upon keyup event. So my question is, Are there better ways to validate input in keydown event than checking keyCode by keyCode? Are there other ways to capture the user inputs other than keydown event before browser displays it? And a way to put the validation on it? Thanks for the help in advance.

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Structure's with strings and input

- by Beginnernato

so i have the following structure and function that add's things to the function - struct scoreentry_node { struct scoreentry_node *next; int score; char* name; } ; typedef struct scoreentry_node *score_entry; score_entry add(int in, char* n, score_entry en) { score_entry r = malloc(sizeof(struct scoreentry_node)); r->score = in; r->name = n; r->next = en; return r; } i have input that take it in the following main file: int score; char name[]; int main(void) { score_entry readin = NULL; while(1) { scanf("%s%d", name, &score); readin = add(score, name, readin); // blah blah I dont know why but when input a name it gets added to readin, but when i input another name all the name's in readin have this new name for example: input: bob 10 readin = 10 bob NULL jill 20 readin = 20 jill 10 jill NULL I dont know why bob disappear's... any reason why it does that ?

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Input signal out of range; Change settings to 1600 x 900

- by Clayton

I recently installed Ubuntu 12.04 onto my HP Pavilion, in an attempt to make the desktop able to dual-boot Windows 7 and Ubuntu. I managed to get down to the last step, and finished the installation process. After it prompted me to remove what I used to install Ubuntu, I did so, removing my SanDisk 8GB flash drive, and allowed the system to reboot. Like usual, the desktop booted with the HP image, with the options at the bottom(Boot Menu, System Recovery, etc). However, when it should have started up with Ubuntu(like I'm certain it should have done), I received the following error: Input signal out of range Change settings to 1600 x 900 From the time I installed the operating system, back in late August, till now, I've been trying to figure out how I would go about fixing this issue. My mom is also starting to get frustrated with my not having resolved the issue, as its the only desktop that has a printer installed. Is there any possible way to resolve this? To summarize the problem: -Successful boot -Screen brings up error -Screen goes to standby -Nothing else possible until desktop is rebooted, which will initiate the above three steps A few notes: -I did not back up my computer before I installed Ubuntu. I didn't have anything to write to, and basically just forgot to. : -I don't have a Recovery Disk. -I don't have the Windows 7 disk that is supposed to come with the computer. -It has been narrowed down by a friend on Skype that the problem lies with the display, and that the vga= boot command does have something to do with fixing the problem Thank you in advance for resolving this problem. I greatly appreciate it. ^^

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Should I learn two (or more) programming languages in parallel?

- by c_maker

I found entries on this site about learning a new programming language, however, I have not come across anything that talks about the advantages and disadvantages of learning two languages at the same time. Let's say my goal is to learn two new languages in a year. I understand that the definition of learning a new language is different for everyone and you can probably never know everything about a language. I believe in most cases the following things are enough to include the language in your resume and say that you are proficient in it (list is not in any particular order): Know its syntax so you can write a simple program in it Compare its underlying concepts with concepts of other languages Know best practices Know what libraries are available Know in what situations to use it Understand the flow of a more complex program At least know most of what you do not know I would probably look for a good book and pick an open source project for both of these languages to start with. My questions: Is it best to spend 5 months learning language#1 then 5 months learning language#2, or should you mix the two. Mixing them I mean you work on them in parallel. Should you pick two languages that are similar or different? Are there any advantages/disadvantages of let's say learning Lisp in tandem with Ruby? Is it a good idea to pick two languages with similar syntax or would it be too confusing? Please tell me what your experiences are regarding this. Does it make a difference if you are a beginner or a senior programmer?

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Rogue black-box java application not responding to standard input redirect

- by Stefan Kendall

I have an external java application (blackbox), which requires authentication. I need to run this application in a batch setting, but it seems to be reading from standard input in some nonstandard way. That is, if I set the calling of the program to redirect STDIN to a file (... <password.txt) or pipe data to it (echo mypasword | ...), it does not recognize the input. As I run it, also, it seems to intercept Cntrl+c and Cntrl+d and Cntrl+z as legitimate password characters, so it must be doing something odd and not just reading from standard in. Any idea what this application could be doing to read in input? I need to be able to send it information programmatically, and I'm stumped for the moment.

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Java input method for Virtual Keyboad

- by shekhar

Hi, I am facing problem in implementing Input method for Virtual Keyboard, currently I am using robot class for sending input to any application from virtual keyboard. but for that I need to create mapping of key-code and unicode, which is not consistent on different keyboard layout, can I directly pass the UNICODE to any application using Input method without worry about mapping between keycode and unicode. any useful link or sample code will be useful. It is simple Java program which is always on top of any application and work as onscreen keyboard. using a mouse while you press any button (key) of the keyboard, the corresponding character will be typed in the application running below. This is working perfectly for English Alphabets. I am facing problem while I am doing for unicode.

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Pygame program that can get keyboard input with caps

- by None

I have a Pygame program that needs text input. The way it does this is to get keyboard input and when a key is pressed it renders that key so it is added to the screen. Essentially it acts like a text field. The problem is, when you hold shift it doesn't do anything. I relize this is because the program ignores shift input and instead writes the text if it's number is under 128. I have thought of setting a variable when shift is pressed then capitalizing if it was true, but string capitalization only woks on letters, not things like numbers or semicolons. Is there maybe a number I can add to the ascii number typed to modify it if shift is pressed, or something else?

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How to give a input date format in iphone

- by Pugal Devan

Hi, i am new to iphone development. In my input date format is "2010-03-05T18:20:40Z", and i donno to how to give a input format of my code.So i have mentioned in my code (?). input date format = "2010-03-05T18:20:40Z" Here my code is: NSString *indate = @"2010-03-05T18:20:40Z"; NSDateFormatter *inputFormatter = [[NSDateFormatter alloc] init]; [inputFormatter setDateFormat:@"????????????????????????"]; NSDate *inputDate = [inputFormatter dateFromString:indate]; NSDateFormatter *outputFormatter = [[NSDateFormatter alloc] init]; [outputFormatter setDateFormat:@"EEE. MMM. d, yyyy"]; NSString *outputDate = [outputFormatter stringFromDate:inputDate]; lDate.text = outputDate; Plz help me out. Thanks.

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Html Birthdate input usability best practice

- by Andrew Florko

Hello everybody, I am going to implement standard functionality - birthdate input on web form for PC. There are lots of interfaces how to implement this. Date picker (OMG, I can't stand picking date with it. Too many clicks required) 3 Dropdown lists. Day, Month, Year. (I am not very fond of it though - they are too long) Straightforward input: DD.MM.YYYY (My choice, but I am programmer, not a customer) ... some more What kind of input do you prefer? What is the worst one for your opinion?

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edge case for selecting a checked radio input with jquery

- by altvali

Hi all! I have a problem selecting a checked radio button with jquery. The radio buttons are generated by a function from a MVC that i'd rather not change and its name is like id[number]. Simply put, I have to check if any of these buttons are checked: <input type="radio" name="id[1]" value="1"/ <input type="radio" name="id[1]" value="2"/ The problem is that jQuery('input:radio[name=id[1]]:checked').val() will select some function from the jQuery library. Any help will be much appreciated.

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Good input validation loop using cin - C++

- by Alex

Hi there, I'm in my second OOP class, and my first class was taught in C#, so I'm new to C++ and currently I am practicing input validation using cin. So here's my question: Is this loop I constructed a pretty good way of validating input? Or is there a more common/accepted way of doing it? Thanks! Code: int taxableIncome; int error; // input validation loop do { error = 0; cout << "Please enter in your taxable income: "; cin >> taxableIncome; if (cin.fail()) { cout << "Please enter a valid integer" << endl; error = 1; cin.clear(); cin.ignore(80, '\n'); } }while(error == 1);

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jQuery default/placeholder input text and problems with saved information

- by user318106

Hey Guys, I'm new to jQuery and have an annoying problem. I have some login fields that are filled with default text when the field is empty and then removed when clicked. My problem is that when the user has their username/password saved (with browser), if they return to the page the login fields are filled with the users saved input as well as the default input. $('#login input.text').each(function(i, field) { field = $(field); if (field.val().length 0) { field.prev().css('display', 'none'); } field.focus(function() { field.prev().css('display', 'none'); }).blur(function() { if (field.val() == '') field.prev().css('display', 'block'); }); })

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input default value Jquery

- by venom

$(".box_yazi2").each(function() { var default_value = this.value; $(this).css('color', '#555'); // this could be in the style sheet instead $(this).focus(function() { if(this.value == default_value) { this.value = ''; $(this).css('color', '#000'); } }); $(this).blur(function() { if(this.value == '') { $(this).css('color', '#555'); this.value = default_value; } }); }); }); This function of default value of input doesnt work in FF, but perfectly works in IE and ofcourse the input itself looks like this: <input type="text" class="box_yazi2" id="konu" name="konu" value="Bos" />

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Stuck on conditionally enable or disable input with JQuery

- by dmr

I am attempting to conditionally enable or disable HTML input based on the value of a variable. The "disable" part is working well, but the "enable" isn't, and I can't figure out why. The code: <--if variable is true...--> <div id="disabledSearch" class="searchBox disabled"> <script type="text/javascript"> $('#disabledSearch :input').attr('disabled', true); </script> <--if variable is false--> <div id="enabledSearch" class="searchBox"> <script type="text/javascript"> //This line isn't working: $('#enabledSearch :input').removeAttr('disabled'); </script>

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How to change input button image using CSS?

- by Baltimark

So, I can create an input button with an image using <INPUT type="image" src="/images/Btn.PNG" value=""> But, I can't get the same behavior using CSS. for instance, i've tried <INPUT type="image" class="myButton" value=""> where "myButton" is defined in the css file as .myButton{ background:url(/images/Btn.PNG) no-repeat; cursor:pointer; width: 200px; height: 100px; border: none; } If that's all I wanted to do, I could use the original style, but I want to change the button's appearance on hover (using a myButton:hover class). I know the links are good because I've been able to load them for a background image for other parts of the page (just as a check). I found examples on the web of how to do it using javascript, but I'm looking for a css solution. I'm using Firefox 3.0.3 if that makes a difference. Thanks

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Use text input as php variable

- by Thomas Lai

<input type="text" onkeydown="domaincheck()" /> <?php function domaincheck() { $recordexists = checkdnsrr("", "ANY"); if ($recordexists) echo "The domain name has been taken. Sorry!"; else echo "The domain name is available!"; } ?> I want my php code to process the text input and say if it's a valid domain or not. The only thing that doesn't work is linking the input to the php.

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python input UnicodeDecodeError:

- by The man on the Clapham omnibus

python 3.x >>> a = input() hope >>> a 'hope' >>> b = input() håpe >>> b 'håpe' >>> c = input() start typing hå... delete using backspace... and change to hope Traceback (most recent call last): File "<stdin>", line 1, in <module> UnicodeDecodeError: 'utf8' codec can't decode byte 0xc3 in position 1: invalid continuation byte >>> The situation is not terrible, I am working around it, but find it strange that when deleting, the bytes get messed up. Has anyone else experienced this? the terminal history shows that I thought that I entered h?ope any ideas? in the script that is using this, I do import readline to give command line history.

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JAVA: How do I accept input during a certain period of time only

- by sebrock

Im trying to do a simple game where I continually need input from players. This needs to happen during a certain time period only. Everything that is sent after that will be discarded. After the time period a new game starts. So: Start game Wait for input from all players during 10 seconds 10 secs no more input Calculate the winner and do some stuff Goto 1. I was thinking using a timer and timertask to keep track of time and maybe use a boolean variable that changes from "open" to "closed" after 10 seconds? Please give me some advise on this.

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Limitation of high level languages? [closed]

- by user1705796

My question may look bit philosophical and nonsense! But I need to know kind of instructions those are not well suitable in high level languages even in c? Or rarely use in the development of software? Like read/write content of CPU registers may useful in debugging programs. And access to cache memory required when developing OS (maybe I am wrong at this point). Is this kind of instruction available languages like Java, Python, C? I also have a second question: And Why all high level languages not having same uniform syntax; at-least same standard library interface name? In python there is and. Or operator is almost same as && and ||. I think Python is developed after C but space indentation is compulsory in Python. Why Python does not use brackets {}. I already know this question going to be highly down-voted.

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Disable input fields based on selection from drop down

- by Thomas

I have a drop down box and some text input fields below it. Based on which item from the drop down menu the user selects, I would like to disable some of the fields. I think I am failing to target the input fields correctly but I can't figure out what the problem is: Here is the script I have gotten so far: $(document).ready(function(){ var customfield = $('#customfields-tf-19-tf'); var customfield1 = $('#customfields-tf-20-tf'); var customfield2 = $('#customfields-tf-13-tf'); $(function() { var call_table = { 'Condominium': function() { customfield.attr("disabled"); }, 'Co-Op': function() { customfield1.attr("disabled"); }, 'Condop': function() { customfield2.attr("disabled"); } }; $('#customfields-s-18-s').change(function() { call_table[this.value](); }); }); }); And the layout for my form: <td width="260" class="left"> <label for="customfields-s-18-s">Ownership (Required):</label> </td> <td class="right"> <select name="customfields-s-18-s" class="dropdown" id="customfields-s-18-s" size="" > <option value="Condominium"> Condominium</option> <option value="Co-Op"> Co-Op</option> <option value="Condop"> Condop</option> </select> </td> </tr> <tr> <td width="260" class="left"> <label for="customfields-tf-19-tf">Maintenance:</label> </td> <td class="right"> <input type="text" title="Maintenance" class="textInput" name="customfields-tf-19-tf" id="customfields-tf-19-tf" size="40"/> </td> </tr> <tr id="newsletter_topics"> <td width="260" class="left"> <label for="customfields-tf-20-tf">Taxes:</label> </td> <td class="right"> <input type="text" title="Taxes" class="textInput" name="customfields-tf-20-tf" id="customfields-tf-20-tf" size="40" /> </td> </tr> <tr> <td width="260" class="left"> <label for="customfields-tf-13-tf" class="required">Tax Deductibility:</label> </td> <td class="right"> <input type="text" title="Tax Deductibility" class="textInput" name="customfields-tf-13-tf" id="customfields-tf-13-tf" size="40" /> </td> </tr>

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move carat to the end of a text input field AND make the end visible

- by user322384

I'm going insane. I have an autosuggest box where users choose a suggestion. On the next suggestion selection the value of the text input box exceeds its size. I can move the carat to the end of the input field crossbrowser, no problem. But on Chrome and Safari I cannot SEE the carat at the end. The end of the text is not visible. Is there a way to move the carat to the end of a text input field AND have the end of the field visible so that the user is not confused about where the input carat went? what I got so far: <html> <head><title>Field update test</title></head> <body> <form action="#" method="POST" name="testform"> <p>After a field is updated the carat should be at the end of the text field AND the end of the text should be visible</p> <input type="text" name="testbox" value="" size="40"> <p><a href="javascript:void(0);" onclick="add_more_text();">add more text</a></p> </form> <script type="text/javascript">  </script> </body> </html> Thanks

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What do you mean by the expressiveness in a programming language?

- by prosseek

I see a lot of the word 'expressiveness' when people want to stress one language is better than the other. But I don't see exactly what they mean by it. Is it the verboseness/succinctness? I mean, if one language can write down something shorter than the other, does that mean expressiveness? Please refer to my other question - http://stackoverflow.com/questions/2411772/article-about-code-density-as-a-measure-of-programming-language-power Is it the power of the language? Paul Graham says that one language is more powerful than the other language in a sense that one language can do that the other language can't do (for example, LISP can do something with macro that the other language can't do). Is it just something that makes life easier? Regular expression can be one of the examples. Is it a different way of solving the same problem: something like SQL to solve the search problem? What do you think about the expressiveness of a programming language? Can you show the expressiveness using some code? What's the relationship with the expressiveness and DSL? Do people come up with DSL to get the expressiveness?

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Display a input type=file over another input type=file

- by Kevin Sedgley

WARNING: Lengthy description coming up! I have written an uploader based upon APC progress uploader for PHP. This works fine and dandy, but the script as a whole (apc etc) is intended to be used only for those with Javascript. To achieve this, I have searched for any input type=file, and replaced these with an absolutely positioned form that appears over the original area where the old file input area was. The reasons for this are so the new uploader can submit to a hidden in page IFrame has to be in a seperate <form> in order to submit to the APC reciever to display the progress upload bar. allows it to be used within any form with an input type=file throughout the site I have used JQuery to do this, with the following code: Original HTML form code: <div><input type="file" name="media" id="media" /></div> Find position of div block code: // get the parent div, and properties thereof parentDiv = $(this).closest('div'); w = $(parentDiv).width(); h = $(parentDiv).height(); loc = $(parentDiv).offset(); Locate new block over old block: $('#_sender').appendTo('body').css({left:loc.left,top:loc.top,position:'absolute',zIndex:400,height:h,width:w}).show(); This works fine, and shows over the old block OK. The problem: When other elements in the DOM before or above it change (in this case a "tree view" selector is pushing the old block down) the new upload form gets moved over other elements. Is there a JQuery (or JS) method for changing this upon DOM change? Some kind of .onchange for the page?! Or an .onmove for the original block? Thanks in advance you lovely people Before DOM change: . After: .

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Search found 21980 results on 880 pages for 'input languages'.

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- by Giorgio

- by c411

- by Beginnernato

- by Clayton

- by c_maker

- by Stefan Kendall

- by shekhar

- by None

- by Pugal Devan

- by Andrew Florko

- by altvali

- by Alex

- by user318106

- by venom

- by dmr

- by Baltimark

- by Thomas Lai

- by The man on the Clapham omnibus

- by sebrock

- by user1705796

- by Thomas

- by user322384

- by prosseek

- by Kevin Sedgley

- by TomWij

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