There are submodules in the module Stdlib. How can I access them? For example, the natural Stdlib.Fun.id causes
Error: Unbound module Stdlib.Fun
There are a lot of tutorials on OCaml module system, but they all consider only one level of hierarchy. At least, I did not found otherwise.
You access them exactly like that. The error message says that Stdlib.Fun does not exist. Stdlib.Fun was added in 4.08, and Stdlib itself was added in 4.07 (before that you could only reference the standard library modules directly). Therefore, if you use a version of OCaml older than 4.08, this specific invocation won't work.
At time of writing, the latest version of the compiler is 4.10. You might want to upgrade to that to avoid further surprises like this.
Related
I have already built pypi package stored on pypi server few days back. Now I want to compare source code diff between already built pypi package and recent code built today. Is there any way to this?
I want to compare already built pypi package and newly build code. And If there is any difference in source code then only create a new package and upload it to pypi server
If you have only Python bytecodes, you cannot get the corresponding source code (that hypothetical transformation is called decompilation, and is not possible in general; read e.g. about Rice's theorem). Since any translation (such as the one done by the python program) from source code to bytecode is losing some information (e.g. name of local variables, comments explaining the intent of the code).
Equality of the behavior of functions by static analysis of their source code (and the observable behavior of your code is what you really care about) is an undecidable problem. Learn more about λ-calculus, it is deeply related to that question.
The source code (by definition, the preferred form of code on which developers work) is not only for computers, but mostly for fellow developers: in other words, most of its value and its meaning is a social one (and that is what free software is about). Read more about the semantics of programs.
For example, renaming a variable from i to x may convey the implicit hypothesis that the intended dynamic runtime type of the value of that variable was an integer, and becomes a floating point.
Maybe you want some kind of package manager (or some version control system, if you deal with source code, or some build automation tool, if you build then install software out of it). Python has something to manage packages. The scons build automation uses Python, but there are many other build automation tools, GNU make being a common one (that you could use to drive compilation from .py source files to .pyc bytecode files and their installation). For version control, I recommend git.
PS. Your question is very unclear and smells like some XY problem.
How can one programmatically determine which type libraries (GUID and version) a given native, VB6-generated DLL/OCX depends on?
For background: The VB6 IDE chokes when opening a project where one of the referenced type libraries can't load one of its dependencies, but it's not so helpful as to say which dependency can't be met--or even which reference has the dependency that can't be met. This is a common occurrence out my company, so I'm trying to supplement the VB6 IDE's poor troubleshooting information.
Relevant details/attempts:
I do have the VB source code. That tells me the GUIDs and versions as of a particular revision in the repo, but when analyzing a DLL/OCX/TLB file I don't know which version of the repo (if any--could be from a branch or might never have been committed to a branch) a given DLL/OCX corresponds to.
I've tried using tlbinf32.dll, but it doesn't appear to be able to list imports.
I don't know much about PE, but I popped open one of the DLLs in a PE viewer and it only shows MSVBVM60.dll in the imports section. This appears to be a special quirk of VB6-produced type libraries: they link only to MSVBVM60 but have some sort of delay-loading mechanism for the rest of the dependencies.
Even most of the existing tools I've tried don't give the information--e.g., depends.exe only finds MSVBVM60.dll.
However: OLEView, a utility that used to ship with Visual Studio, somehow produces an IDL file, which includes the importlib directives. Given that VB doesn't use IDL files, it's clearly generating the information somehow. So it's possible--I just have no idea how.
Really, if OLEView didn't do it I'd have given it up by now as impossible. Any thoughts on how to accomplish this?
It turns out that I was conflating basic DLL functionality and COM. (Not all DLLs are COM DLLs.)
For basic DLLs, the Portable Executable format includes a section describing its imports. The Optional Header's directory 1 is about the DLL's imports. Its structure is given by IMAGE_IMPORT_DESCRIPTOR. This is a starting point for learning about that.
COM DLLs don't seem to have an equivalent as such, but you can discover which other COM components its public interface needs: for each exposed interface, list out the types of their properties and their method arguments, and then use the Registry to look up where those types come from. tlbinf32.dll provides some of the basic functionality for listing members, etc. Here's and intro to that.
I have been reading about semver. I really like the general idea. However, when it comes to putting it to practice, I feel like I'm missing some key pieces of information. I'm not sure where the name of a library exists, or what to do with file variants. For instance, is the file name something like [framework]-[semver].min.js? Are there popular JavaScript frameworks that use semver? I don't know of any.
Thank you!
Let me try to explain you.
If you are not developing a library that you like to keep for years to come, don't bother about it.. If you prefer to version every development, read the following.
Suppose you are an architect or developer developing a library that is aimed to be used by hundreds of developers over time, in a distributed manner. You really need to be cautious of what you are doing, what your developers are adding (so interesting features that grabs your attention to push those changes in the currently distributed file). You dont know how do you tell your library users to upgrade. In what scenarios? People followed some sort of versioning, and interestingly, their thoughts all are working fine.
Then why do you need semver ?
It says "There should be a concrete specification for anything for a group of people to follow anything collectively, even though they know it in their minds". With that thought, they made a specification. They have made their observation and clubbed all the best practices in the world about versioning software mainly, and given a single website where they listed them. that is semver.org. Its main principles are :
Imagine you have already released your library with a version "lib.1.0.98", Now follow these rules for subsequent development.
Let your library is bundled and named as xyz and,
Given a version number MAJOR.MINOR.PATCH, (like xyz.MAJOR.MINOR.PATCH), increment the:
1. MAJOR version when you make incompatible API changes
(existing code of users of your library breaks if they adapt this without code changes in their programs),
2. MINOR version when you add functionality in a backwards-compatible manner
(existing code works, and some improvements in performance and features also), and
3. PATCH version when you make backwards-compatible bug fixes.
Additional labels for pre-release and build metadata are available as extensions to the MAJOR.MINOR.PATCH format.
If you are not a developer or are not in a position to develop a library of a standard, you need not worry at all about semver.
Finally, the famous [d3] library follows this practice.
Semantic Versioning only defines how to name your versions. It does not specify what you will do with your version number afterwards. You can put the version numbers in package names, you can store it in a properties file inside your application, or just publish it in a wiki. All those options are opened to discussion and not part of the problem space addressed by SemVer.
semver is used by npm and bower (and perhaps some other tools) for dependency management. Using semver it is possible to decide which versions of which packages to use if multiple libraries used depend on the same library.
As others have said, semantic versioning is a standard versioning scheme that tells your users which versions of your library should be compatible with each other, and which ones are not.
The idea, is to be able to give your users more confidence that it's safe to upgrade to a newer patch/version, because it's tried, tested, and true to being backwards compatible with the previous version (minor increments). That is, perceptively that's what your telling your users.
As far as tooling goes, I don't do much in javascript, but I typically let my build server handle stamping my assemblies etc with the correct version. I have a static major number I upgrade whenever I make breaking changes, a static minor number I upgrade everytime I add new features, and an auto-incrementing Patch number whenever I checkin bug fixes.
Especially if this is a javascript library you plan to share on a public repository of some kind (nuget, gem, etc) you probably want some for of automated packaging system, and you put the logic in there for specifying your version number (in the package meta data, in the name of the javascript file, which is typically the standard I've seen).
Take a look at sbt which is the Scala Build Tool. In it, we write dependencies like this:
val scalatest = "org.scalatest" %% "core" % "2.1.7" "test"
val jodatime = "org.joda" % "jodatime" % "1.4.5"
Wherein the operator %% means "the current version of Scala that you're building." Packaging things in this language generally create JAR files with the name like this <my project>_<scala version>_<library version>.jar which is quite handy for semantically naming things automagically. The % operator can be interpreted as "don't version this part."
That said, this resulted from the fact that the same library compiled to different Scala versions were not binary compatible with each other. So it was more as a result of, rather than a conscious design choice, the binary incompatibilities.
I mean this module : Option
I can't find it, open Option gives me Error: Unbound module Option and there is no 'option.cma' file
Is it in the standard library ? Is it named 'option.cma' ?
This is not part of the OCaml standard library, no. It looks like it might be part of a former library named Extlib. Extlib, in turn, seems to have become part of OCaml Batteries Included. The Option module is now named BatOption.
If you want this module, you should get OCaml Batteries Included. Then you need to tell the OCaml compiler how to find the library. It will be explained in the installation instructions for Batteries.
In my project, there are 2 libraries, each of which depend on the XML parsing class java.xml.parsers.DocumentBuilderFactory. Each of these libraries reference the file from different jar (one gets it from a jar called xmlParserAPIs while another gets it from xml-apis-1.0.b2.jar). Unfortunately there are different versions of the class in each of these files so I am seeing runtime errors, depending on the order they are loaded. Both of these xml jars are transitive dependencies of 3rd party libraries. Is there a good way to handle this conflict?
edit: I'm not sure if it makes a difference on how to handle the problem but this only happens in testing because one of the dependencies is in the test scope.
thanks,
jeff
(...) Unfortunately there are different versions of the class in each of these files so I am seeing runtime errors, depending on the order they are loaded.
In theory, xml-apis.jar and xmlParserAPIs.jar (from xerces2-j) are the same JARs but with different names, xmlParserAPIs.jar being deprecated for years (see this message and this one).
If your dependencies relies on different and incompatible versions of xml-apis.jar, I would say that these dependencies are mutually exclusive, in other words incompatible, at least for the versions you're using. The only solution would be to find versions with a converging dependency.
In case they could use compatible versions, use a dependency exclusion for xmlParserAPIs.jar to use xml-api.jar only.
I'm not sure if it makes a difference on how to handle the problem but this only happens in testing because one of the dependencies is in the test scope.
No, this just explains why you don't get the problem at runtime (because the test scoped is not on the classpath then and, obviously, doesn't conflict).