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问题 I'm trying to learn scheme by myself. Could anyone tell me why '(quote quote) will output 'quote , and '(quote 'quote) will output ''quote ? Thank you very much! 回答1: This expression: '(quote quote) ... after expanding '<something> to (quote <something>) is equivalent to (quote (quote quote)) , notice that the symbol quote is being quoted two times, and this expression is evaluated and printed as ''quote . On the other hand, this expression: '(quote 'quote) ... is equivalent to (quote (quote

问题 I'm trying to learn LISP and was going through a code example where something similar to the following code is used: (list 'quote 5) This evaluates to '5 in the REPL. I expected it to evaluate to ('5) or (quote 5) I'm trying this out in the CLISP REPL. Any help would be appreciated. 回答1: The read-evaluate-print loop first reads, then evaluates 'quote is read as "the symbol whose name is QUOTE" 5 is read as "the number 5" So (list 'quote 5) is evaluated as "make a list whose first element is

问题 I'm trying to learn LISP and was going through a code example where something similar to the following code is used: (list 'quote 5) This evaluates to '5 in the REPL. I expected it to evaluate to ('5) or (quote 5) I'm trying this out in the CLISP REPL. Any help would be appreciated. 回答1: The read-evaluate-print loop first reads, then evaluates 'quote is read as "the symbol whose name is QUOTE" 5 is read as "the number 5" So (list 'quote 5) is evaluated as "make a list whose first element is

问题 What is the preferred way to write Python doc string? """ or " In the book Dive Into Python, the author provides the following example: def buildConnectionString(params): """Build a connection string from a dictionary of parameters. Returns string.""" In another chapter, the author provides another example: def stripnulls(data): "strip whitespace and nulls" return data.replace("\00", "").strip() Both syntax work. The only difference to me is that """ allows us to write multi-line doc. Is

问题 From reading introductory material on Lisp, I now consider the following to be identical: (list 1 2 3) '(1 2 3) However, judging from problems I face when using the quoted form in both Clojure and Emacs Lisp, they are not the same. Can you tell me what the difference is? 回答1: The primary difference is that quote prevents evaluation of the elements, whereas list does not: user=> '(1 2 (+ 1 2)) (1 2 (+ 1 2)) user=> (list 1 2 (+ 1 2)) (1 2 3) For this reason (among others), it is idiomatic

问题 I'm using superCSV for exporting bean data to CSV. I'd like every cell double quoted, not just the ones with special characters. Now, using CsvPreference.EXCEL_NORTH_EUROPE_PREFERENCE, even the cells with special characters won't get quoted. (With EXCEL_PREFERENCE setting the addresses that contain '.' get quoted.) My goal is to export addresses, phone numbers, everything in a way that MS Office (Hungarian) can use and i.e. won't convert phone numbers like +36000000000 to 36000000000. 回答1:

问题 I have a set of data inside the csv as below: Given Data: (12,'hello','this girl,is lovely(adorable \r\n actually)',goodbye), (13,'hello','this fruit,is super tasty (sweet actually)',goodbye) I want to print the given data into 2 rows starting from ( till ) and ignore delimiter , and () inside the ' ' field. How can I do this using awk or sed in linux? Expected result as below: Expected Result: row 1 = 12,'hello','this girl,is lovely(adorable actually)',goodbye row 2 = 13,'hello','this fruit

问题 What's the difference between: (cons 'a (cons 'b 'c)) ;; (A B . C) and (cons 'a '(b.c)) ;; (A B.C) I need to create the following list ((a.b).c) using cons so i'm trying to understand what that "." represents. L.E. : I have the following (cons (cons 'a 'b) 'c) but it produces ((A . B) . C) and not ((A.B).C) (Note the extra spaces) 回答1: Spaces are used to separate list tokens. A.B is a single token. (A.B) is a list with a single element. (A . B) is a cons cell with A as car and B as cdr. A

问题 I'm trying to create an alias for a command to see the memory use, ps -u user -o rss,command | grep -v peruser | awk '{sum+=$1} END {print sum/1024}' but, the naive, #.bash_aliases alias totalmem='ps -u user -o rss,command | grep -v peruser | awk '{sum+=$1} END {print sum/1024}'' gives errors: -bash: alias: END: not found -bash: alias: {print: not found -bash: alias: sum/1024}: not found I've tried with double quotes, totalmem ="ps ... |awk '{sum+=$1} END {print sum/1024}'" , or totalmem ='ps

问题 I'm trying to echo a js function in HTML string inside PHP echo. And I can't figure it out : $MY_JS_FUNCTION = '<script type="text/javascript">item + getLastField2()</script>'; if($row2->type == 'text') { echo "<li id='item-".$row2->rank."' class='list_item'>"; echo "<textarea rows='2' id='".$row2->single_id."' cols='90' name='field[".$MY_JS_FUNCTION."]' data-kind='text' >".$row2->content."</textarea>"; echo "</li>"; echo '<br />'; } Any ideas to get this work? I think I have so much quotes