lexical

Common Lisp scoping (dynamic vs lexical)

由 折月煮酒 提交于 2019-12-31 10:01:49
问题 EDIT: I changed the example code after the first answer because I came up with a simple version that begs the same questions. I am currently learning Common Lisp's scoping properties. After I thought I had a solid understanding I decided to code up some examples that I could predict the outcome of, but apparently I was wrong. I have three question, each one relating to an example below: Example 1: (defmethod fun1 (x) (print x) (fun2)) (defmethod fun2 () (print x)) (fun1 5) Output: 5 *** -

Common Lisp scoping (dynamic vs lexical)

由 折月煮酒 提交于 2019-12-31 10:01:48
问题 EDIT: I changed the example code after the first answer because I came up with a simple version that begs the same questions. I am currently learning Common Lisp's scoping properties. After I thought I had a solid understanding I decided to code up some examples that I could predict the outcome of, but apparently I was wrong. I have three question, each one relating to an example below: Example 1: (defmethod fun1 (x) (print x) (fun2)) (defmethod fun2 () (print x)) (fun1 5) Output: 5 *** -

How to sort pandas dataframe non-lexical?

由 本小妞迷上赌 提交于 2019-12-25 07:30:29
问题 What I do to sort credit in the following dataframe is to use sort_values() function (I've also tried sort()): df.sort_values('credit', ascending=False, inplace=True) The problem is that credits are sorted like below: i credit m reg_date b id ---------------------------------------------------------------------- 238 0 4600000.00 0 2014-04-14 False 102214 127 0 4600000.00 0 2014-12-30 False 159479 13 0 16800000.00 0 2015-01-12 False 163503 248 0 16720000.00 0 2012-11-11 False 5116 Ascending is

How to combine Regexp and keywords in Scala parser combinators

由 三世轮回 提交于 2019-12-21 19:50:15
问题 I've seen two approaches to building parsers in Scala. The first is to extends from RegexParsers and define your won lexical patterns. The issue I see with this is that I don't really understand how it deals with keyword ambiguities. For example, if my keyword match the same pattern as idents, then it processes the keywords as idents. To counter that, I've seen posts like this one that show how to use the StandardTokenParsers to specify keywords. But then, I don't understand how to specify

Why can't I use a Perl variable's value to access a lexical variable name?

由 浪子不回头ぞ 提交于 2019-12-21 12:23:00
问题 Why does this print 42: $answer = 42; $variable = "answer"; print ${$variable} . "\n"; but this doesn't: my $answer = 42; my $variable = "answer"; print ${$variable} . "\n"; 回答1: Only package variables (the kind declared in your first example) can be targeted via symbolic references. Lexical ( my ) variables, cannot be, which is why your second example fails. See the excellent article Coping with Scoping for how the two separate variable systems in Perl operate. And see the also excellent Why

Using the wrong escape character for Lucene lexical error at line 1 Cannot Parse Encountered <EOF>. Kentico 12

由 China☆狼群 提交于 2019-12-13 18:03:33
问题 I have a similar issue as the following question: Lucene error while parsing Query: Cannot parse '': Encountered “” at line 1, column 0, and I had already tried all the escaping. What else could it be? I'm using Kentico 12 hotfix 14, with their Lucene.NET 3.0.3 implementation. My Smart Search Index uses the Standard analyzer, see below: I get the expected rows back when I use the following lucene syntax to pull back an en-US culture result. This syntax is automatically created by Kentico and

Why does my R run in dynamic scoping? Shouldn't it be lexical?

由 霸气de小男生 提交于 2019-12-09 03:58:41
问题 I just learned in class that R uses lexical scoping, and tested it out in R Studio on my computer and I got results that fit dynamic scoping, not lexical? Isn't that not supposed to happen in R? I ran: y <- 10 f <- function(x) { y <- 2 y^3 } f(3) And f(3) came out to be 4 (2^3) not 100 (10^3), even though my class presented this slide: http://puu.sh/pStxA/0545079dbe.png . Isn't that dynamic scoping? I may just be looking at this wrong, but is there a mode on a menu somewhere where you can

What is the difference between corpus and lexicon in NLTK (python) [closed]

由 為{幸葍}努か 提交于 2019-12-07 09:36:33
问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 4 years ago . Can someone tell me the difference between a Corpora , corpus and lexicon in NLTK ? What is the movie data set ? what is Wordnet ? 回答1: Corpora is the plural for corpus. Corpus basically means a body, and in the context of Natural Language Processing (NLP), it means a body of text

How to combine Regexp and keywords in Scala parser combinators

由 ≡放荡痞女 提交于 2019-12-04 13:03:41
I've seen two approaches to building parsers in Scala. The first is to extends from RegexParsers and define your won lexical patterns. The issue I see with this is that I don't really understand how it deals with keyword ambiguities. For example, if my keyword match the same pattern as idents, then it processes the keywords as idents. To counter that, I've seen posts like this one that show how to use the StandardTokenParsers to specify keywords. But then, I don't understand how to specify the regexp patterns! Yes, StandardTokenParsers comes with "ident" but it doesn't come with the other ones

Why can't I use a Perl variable's value to access a lexical variable name?

由 …衆ロ難τιáo~ 提交于 2019-12-04 06:27:51
Why does this print 42: $answer = 42; $variable = "answer"; print ${$variable} . "\n"; but this doesn't: my $answer = 42; my $variable = "answer"; print ${$variable} . "\n"; friedo Only package variables (the kind declared in your first example) can be targeted via symbolic references. Lexical ( my ) variables, cannot be, which is why your second example fails. See the excellent article Coping with Scoping for how the two separate variable systems in Perl operate. And see the also excellent Why it's stupid to use a variable variable name for why that's stupid. :) Perl has two entirely separate
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