How can I get information about type of a Go variable - variables

Suppose I have the following code in Go:
foo, bar := someFunc(baz)
I would like to create a Vim function to check type of foo or bar when editing a file.
Is there any tool or reliable source of information for functions from Go's packages I could use or? As for the functions declared in the file I'm editing I was thinking about simply parsing all the functions declared in that file.

You are looking for something like godef
If the -t flag is given, the type of the expression will also be
printed. The -a flag causes all the public members (fields and
methods) of the expression, and their location, to be printed also;
the -A flag prints private members too.
I know it is being used by various vim and emacs scripts.

The Go Oracle does this and much more.
vim-go is a complete vim setup for Go.
It includes integration with the previously mentioned godef (as :GoDef) and Go oracle (as :GoImplements, :GoCallees, :GoReferrers, etc) as well as other tools.

Related

SCIP - run (nearly) same LP on different instances

I have an LP, formulated in the modelling language Zimpl, that I want to run on many instances, which are in different files.
Additionally, I want to change one parameter in this LP.
For a single call, my file test.zpl looks like this:
param FILE := "file1.dat"
param BOUND := 42
[test_body: Rest of LP]
Now I want to change those two parameters. SCIP has the -c option, to execute some command. But I cannot find by which command to achieve this. All parameter changes I found affect the algorithm, not the data.
The command change to change the problem does not seem to allow new parameters/variables.
In the end, I expect the solution to look something like
scip -c "[set my parameters]; read test_body.zpl; optimize; quit"
How do I set these problem parameters?
I am not aware of any commands that support the modification of model parameters as you wish. However, if you don't hardcode the value of param BOUND in the .zpl file (instead, move the value to the .dat file and use a proper read command in the model), then you could procede as follows:
Make a copy of your data file such that each copy contains a distinct value of param BOUND
Call scip.exe separately with each data file (you could also use a simple batch script)

LDIF idempotent apply tool

Before I write one, are there any tools for idempotent applying LDIFs:
If change type is not specified, add or replace an entry (aka UPSERT) (removing any attributes not mentioned in the LDIF record).
If change type is specified process like normal ldapmodify.
I saw someone suggesting ldapmodify -c, but this is meh :) I want to catch all errors.
I'm writing a new tool. Something like this https://github.com/ip1981/ldapply

How exactly do you use variables in Jenkins?

Can someone concisely explain what the differences between the three variables below are? Because in all honesty, when I create a Jenkins job, I randomly guess between the three types until something works, but I'd love to understand rather than blindly picking.
${ENV,var="BUILD_USER"}
${BUILD_USER}
$BUILD_USER
Also, are there other ways of writing variables in Jenkins that I missed other than the 3 ways above?
When used in a statement:
${ENV,var="BUILD_USER"}--evaluates the system environment variables and returns the value for the variable BUILD_USER.
example: curl ${ENV,var="BUILD_USER"}/api/xml
${BUILD_USER} --returns the value of the BUILD_USER variable in the current script memory space.
example: curl ${BUILD_USER}/api/xml
$BUILD_USER--used to assign values to the BUILD_USER variable.
example: $BUILD_USER = "BUILD_USER"
In general, variable expansion is up to the plugin that interprets a configuration value.
For example, if you set up a job parameter GIT_REPOSITORY and use it to configure an address where git clone should go by putting $GIT_REPOSITORY into the git repository field, it works, but only because the Jenkins git plugin has implemented variable expansion support.
Many plugins do implement it but you cannot know it unless you test it. However, these days the support is so common it is safe to assume it should work.
Both forms of reference, $VAR and ${VAR}, work and are equivalent. The latter form is useful if you need to use the variable in a place where it is surrounded by other characters that could be interpreted as part of variable, like $VARX (Jenkins would be looking for variable named VARX) and ${VAR}X (Jenkins understands the variable is named VAR).
These rules have been modeled after variable expansion rules in Unix shells. Indeed, the job variables are made available as environment variables to build steps and in the Unix shell build step the variables are used the same way as above.
In a Windows CMD build step the variables are again used like any Windows environment variable: %VAR%.

Renaming a Yakuake session from commandline

Yakuake provides a hotkey and a GUI way to rename commandline tabs/sessions.
I'd like to do the same via the command line, so I can script it and use it in an alias. (My goal is that if I use an alias which does an SSH to some server, then the tab is renamed according to this servers name...)
I tried the suggestions shown here Renaming a Konsole session from commandline after ssh so far no luck.
Since KDE4, one should use qdbus to control KDE apps (instead of deprecated and deleted DCOP).
For example, to change a title of the first session one may use:
qdbus org.kde.yakuake /Sessions/1 org.kde.konsole.Session.setTitle 1 "New title"
To explore available interfaces, methods and properties one may use qdbusviewer.
As a homework try to get a list of active sessions (before you going to change smth).
Like #fgysin pointed out, his command also works for me. BUT it needs the ` character and not " for the subcommand :
qdbus org.kde.yakuake /yakuake/sessions org.kde.yakuake.activeSessionId
It gives :
qdbus org.kde.yakuake /yakuake/tabs org.kde.yakuake.setTabTitle `qdbus org.kde.yakuake /yakuake/sessions org.kde.yakuake.activeSessionId` "NEW TAB TITLE";

Git - how do I view the change history of a method/function?

So I found the question about how to view the change history of a file, but the change history of this particular file is huge and I'm really only interested in the changes of a particular method. So would it be possible to see the change history for just that particular method?
I know this would require git to analyze the code and that the analysis would be different for different languages, but method/function declarations look very similar in most languages, so I thought maybe someone has implemented this feature.
The language I'm currently working with is Objective-C and the SCM I'm currently using is git, but I would be interested to know if this feature exists for any SCM/language.
Recent versions of git log learned a special form of the -L parameter:
-L :<funcname>:<file>
Trace the evolution of the line range given by "<start>,<end>" (or the function name regex <funcname>) within the <file>. You may not give any pathspec limiters. This is currently limited to a walk starting from a single revision, i.e., you may only give zero or one positive revision arguments. You can specify this option more than once.
...
If “:<funcname>” is given in place of <start> and <end>, it is a regular expression that denotes the range from the first funcname line that matches <funcname>, up to the next funcname line. “:<funcname>” searches from the end of the previous -L range, if any, otherwise from the start of file. “^:<funcname>” searches from the start of file.
In other words: if you ask Git to git log -L :myfunction:path/to/myfile.c, it will now happily print the change history of that function.
Using git gui blame is hard to make use of in scripts, and whilst git log -G and git log --pickaxe can each show you when the method definition appeared or disappeared, I haven't found any way to make them list all changes made to the body of your method.
However, you can use gitattributes and the textconv property to piece together a solution that does just that. Although these features were originally intended to help you work with binary files, they work just as well here.
The key is to have Git remove from the file all lines except the ones you're interested in before doing any diff operations. Then git log, git diff, etc. will see only the area you're interested in.
Here's the outline of what I do in another language; you can tweak it for your own needs.
Write a short shell script (or other program) that takes one argument -- the name of a source file -- and outputs only the interesting part of that file (or nothing if none of it is interesting). For example, you might use sed as follows:
#!/bin/sh
sed -n -e '/^int my_func(/,/^}/ p' "$1"
Define a Git textconv filter for your new script. (See the gitattributes man page for more details.) The name of the filter and the location of the command can be anything you like.
$ git config diff.my_filter.textconv /path/to/my_script
Tell Git to use that filter before calculating diffs for the file in question.
$ echo "my_file diff=my_filter" >> .gitattributes
Now, if you use -G. (note the .) to list all the commits that produce visible changes when your filter is applied, you will have exactly those commits that you're interested in. Any other options that use Git's diff routines, such as --patch, will also get this restricted view.
$ git log -G. --patch my_file
Voilà!
One useful improvement you might want to make is to have your filter script take a method name as its first argument (and the file as its second). This lets you specify a new method of interest just by calling git config, rather than having to edit your script. For example, you might say:
$ git config diff.my_filter.textconv "/path/to/my_command other_func"
Of course, the filter script can do whatever you like, take more arguments, or whatever: there's a lot of flexibility beyond what I've shown here.
The closest thing you can do is to determine the position of your function in the file (e.g. say your function i_am_buggy is at lines 241-263 of foo/bar.c), then run something to the effect of:
git log -p -L 200,300:foo/bar.c
This will open less (or an equivalent pager). Now you can type in /i_am_buggy (or your pager equivalent) and start stepping through the changes.
This might even work, depending on your code style:
git log -p -L /int i_am_buggy\(/,+30:foo/bar.c
This limits the search from the first hit of that regex (ideally your function declaration) to thirty lines after that. The end argument can also be a regexp, although detecting that with regexp's is an iffier proposition.
git log has an option '-G' could be used to find all differences.
-G Look for differences whose added or removed line matches the
given <regex>.
Just give it a proper regex of the function name you care about. For example,
$ git log --oneline -G'^int commit_tree'
40d52ff make commit_tree a library function
81b50f3 Move 'builtin-*' into a 'builtin/' subdirectory
7b9c0a6 git-commit-tree: make it usable from other builtins
The correct way is to use git log -L :function:path/to/file as explained in eckes answer.
But in addition, if your function is very long, you may want to see only the changes that various commit had introduced, not the whole function lines, included unmodified, for each commit that maybe touch only one of these lines. Like a normal diff does.
Normally git log can view differences with -p, but this not work with -L.
So you have to grep git log -L to show only involved lines and commits/files header to contextualize them. The trick here is to match only terminal colored lines, adding --color switch, with a regex. Finally:
git log -L :function:path/to/file --color | grep --color=never -E -e "^(^[\[[0-9;]*[a-zA-Z])+" -3
Note that ^[ should be actual, literal ^[. You can type them by pressing ^V^[ in bash, that is Ctrl + V, Ctrl + [. Reference here.
Also last -3 switch, allows to print 3 lines of output context, before and after each matched line. You may want to adjust it to your needs.
Show function history with git log -L :<funcname>:<file> as showed in eckes's answer and git doc
If it shows nothing, refer to Defining a custom hunk-header to add something like *.java diff=java to the .gitattributes file to support your language.
Show function history between commits with git log commit1..commit2 -L :functionName:filePath
Show overloaded function history (there may be many function with same name, but with different parameters) with git log -L :sum\(double:filepath
git blame shows you who last changed each line of the file; you can specify the lines to examine so as to avoid getting the history of lines outside your function.