compilation

问题 I wrote this in scala and it won't compile: class TestDoubleDef{ def foo(p:List[String]) = {} def foo(p:List[Int]) = {} } the compiler notify: [error] double definition: [error] method foo:(List[String])Unit and [error] method foo:(List[Int])Unit at line 120 [error] have same type after erasure: (List)Unit I know JVM has no native support for generics so I understand this error. I could write wrappers for List[String] and List[Int] but I'm lazy :) I'm doubtful but, is there another way

问题 Why would you compile a Python script? You can run them directly from the .py file and it works fine, so is there a performance advantage or something? I also notice that some files in my application get compiled into .pyc while others do not, why is this? 回答1: It's compiled to bytecode which can be used much, much, much faster. The reason some files aren't compiled is that the main script, which you invoke with python main.py is recompiled every time you run the script. All imported scripts

问题 I want to compile my .java's (several) into one .jar that are compatible with at least Java 1.6 and newer, preferably Java 1.5 and newer versions of Java. (I have Java 1.7.0_5 ) 回答1: Yes, you can set the version of compiler at compile time. And compile your java code into old versions of java. From Oracle article : http://docs.oracle.com/javase/1.5.0/docs/tooldocs/windows/javac.html Cross-Compilation Example Here we use javac to compile code that will run on a 1.4 VM. % javac -target 1.4

问题 I encountered an odd situation where appending OPTION (RECOMPILE) to my query causes it to run in half a second, while omitting it causes the query to take well over five minutes. This is the case when the query is executed from Query Analyzer or from my C# program via SqlCommand.ExecuteReader() . Calling (or not calling) DBCC FREEPROCCACHE or DBCC dropcleanbuffers makes no difference; Query results are always returned instantaneously with OPTION (RECOMPILE) and greater than five minutes

问题 We are getting very slow compile times, which can take upwards of 20+ minutes on dual core 2GHz, 2G Ram machines. A lot of this is due to the size of our solution which has grown to 70+ projects, as well as VSS which is a bottle neck in itself when you have a lot of files. (swapping out VSS is not an option unfortunately, so I don't want this to descend into a VSS bash) We are looking at merging projects. We are also looking at having multiple solutions to achieve greater separation of

问题 In the past I have used C++ as a programming language. I know that the code written in C++ goes through a compilation process until it becomes object code "machine code". I would like to know how Java works in that respect. How is the user written Java code run by the computer? 回答1: Java implementations typically use a two-step compilation process. Java source code is compiled down to bytecode by the Java compiler. The bytecode is executed by a Java Virtual Machine (JVM). Modern JVMs use a

问题 The use case is simple. I got the source files that were created using Eclipse. So, there is a deep directory structure, where any Java class could be referring to another Java class in the same, child, sibling or parent folder. How do I compile this whole thing from the terminal using javac ? 回答1: You have to know all the directories, or be able to use wildcard .. javac dir1/*.java dir2/*.java dir3/dir4/*.java dir3/dir5/*.java dir6/*src/*.java 回答2: With Bash 4, you can just enable globstar

问题 New Go programmers often don't know or get confused what the fundamental go build command does. What do exactly the go build and go install commands build and where do they put the result/output? 回答1: What the go command does depends on whether we run it for a "normal" package or for the special "main" package. For packages go build builds your package then discards the results . go install builds then installs the package in your $GOPATH/pkg directory. For commands (package main ) go build

问题 New Go programmers often don't know or get confused what the fundamental go build command does. What do exactly the go build and go install commands build and where do they put the result/output? 回答1: What the go command does depends on whether we run it for a "normal" package or for the special "main" package. For packages go build builds your package then discards the results . go install builds then installs the package in your $GOPATH/pkg directory. For commands (package main ) go build

问题 The Situation Nested within our Angular app is a directive called Page, backed by a controller, which contains a div with an ng-bind-html-unsafe attribute. This is assigned to a $scope var called 'pageContent'. This var gets assigned dynamically generated HTML from a database. When the user flips to the next page, a called to the DB is made, and the pageContent var is set to this new HTML, which gets rendered onscreen through ng-bind-html-unsafe. Here's the code: Page directive angular.module