SALT and Version Control

How to handle projects using version controlled SALT

V1.07

Reasons for external storage

Ever since large IT projects have been going on there has been a need to keep code out of the workspace and manage it, e.g.

- More room needed in the workspace- Backup copies (security)- Modularize code- Code control- Etc.

2Oct 2008

Managing applications• Larger applications have to be

maintained whether they are written in APL or not

• You have to keep track of changes to know who's done what and when

• You must be able to undo changes

• Generally cope with (large) system related problems

3Oct 2008

Managing applications

Apps have been maintained using a combination of workspace and external storage

CodeDB

workspace

4Oct 2008

HowIn APL:• APL files (most common)• Other workspaces ([]CY)• External DBs (e.g. Oracle)• Etc.In other (e.g. compiled)

languages• Text files

5Oct 2008

The rest of the world

APL stands out

APLAPL

6Oct 2008

Managing applications in APLThis makes porting code or even

sharing snippets of it difficult.

- You cannot transport it

- Hard to compare changes

- You need the (proper) interpreter just to VIEW the code

7Oct 2008

Managing applications in APLThere is another way: Unicode text

files

- You can transport them

- You don’t need any interpreter to VIEW them

- They integrate with any text file based control system

8Oct 2008

The rest of the world

APL doesn’t have to stand out

APLAPL

9Oct 2008

UnicodeWith the wider acceptance of Unicode it has

become easier to share code in text files.

• They can be reorganized using Disk Explorer

• APL code can now be cut & pasted and viewed in Notepad or other Unicode compliant editor/program

• It can be distributed

10Oct 2008

Dyalog V11

• This version introduced the scripted form of classes/namespaces

• Their definitions, including functions in them, can be edited.

11Oct 2008

Dyalog V11

• The definition of objects like classes can be retrieved and manipulated like the definition of functions

• And, like the ⎕CR of a function, it can be stored outside the workspace, e.g. in a text (Unicode) file

12Oct 2008

Requirements

All that is needed to store and retrieve text to any Operating System is a pair of functions to

- Store code to a text file- Read a text file into the workspace

Easy enough to do.

13Oct 2008

Requirements

Of course, once you’ve done that you may want to:

- Save multiple copies- Retrieve any of them- List them- Compare them- Etc.

* Basically manage them *

14Oct 2008

Enter...

15Oct 2008

OK, so, what is SALT?

16Oct 2008

SALTSALT is exactly that:

- A pair of functions to store/retrieve - + other functions to list/compare/etc.- + utility functions (e.g. ease

migration of namespaces to text format)

17Oct 2008

SALT

SALT stands for Simple APL Library Toolkit

It is a source code management system for functions, Classes and script-based Namespaces in Dyalog APL.

18Oct 2008

SALT basics

• SALT is tucked away in ⎕SE, this means you can )LOAD and run any workspace anytime

• To save a namespace use Save: ⎕SE.SALT.Save 'myns \path\myfile'

• To bring in a namespace use Load: ⎕SE.SALT.Load '\path\myfile'

23Oct 2008

FeaturesSALT can save back a script on file

right after it has been modified.

After modification you are promptedto confirm saving over the present

script file:

Modify <test>

24Oct 2008

Storing a script with a stackThis can happen if you modify a

function of a class on the stack.

After modification you are prompted toconfirm saving over the present script file.Once saved both the script and the class

are modified and you can resume execution.

Error happens

Stack shows upEdit the function

25Oct 2008

Storing multiple version of a script• You can store and KEEP several

versions of a script.• By using the –version modifier

you tell SALT to start using version numbering:

26Oct 2008

Storing multiple version of a script

Every time you modify a script SALTstores the definition in a new file:

V0 V1

27Oct 2008

=?Showing differences between versions

SALT can show the difference between 2 versions of a script, either

- natively, using APL, or

- using a 3rd party Unicode comparison program

28Oct 2008

=?Showing differences between versions

If ‘APL’ is the method chosen to compare,

the output will appear in the session like this: …

…

lines inserted

lines modified

→ is used to denoteinserted lines

← is used to denotedeleted lines

29Oct 2008

SALT features

SALT has many more features

It is UNIX ready

It comes with tools of its own

It can be extended easily by adding

your own utilities

30Oct 2008

SALT limitations

For small applications it may be

sufficient to keep all code on file

managed by SALT

For larger apps this is clearly

inadequate, you need Version

Control on a grander scale

31Oct 2008

What is Version Control (VC)?

VC is a good way to ensure team members of a project don't step over each others' toes.

On a large project it is imperative to use VC.

Otherwise, time (and money) will be lost trying to recover from coordination problems.

Version Control overviewYou usually start by importing an

existing system (a set of files) into a version control repository:

repositoryoriginal

filesimport

33Oct 2008

Version Control overviewThe original files can then be

forgotten:

repositoryoriginal

files

34Oct 2008

Version Control overviewYou then checkout a subset to work

with:

repository

subset

checkout

originalfiles

35Oct 2008

Version Control overviewYou then work on the subset for a

while:

repository

subset

36Oct 2008

Version Control overviewIf you are using SALT you maintain

the files from APL:

subset

Dyalog APL

37Oct 2008

Version Control overviewEvery once in a while you update the

repository:

repository

subset

Checkin

38Oct 2008

Version Control overviewWhen the repository is in a stable

state you may produce a new release:

repositorynew release export

39Oct 2008

VC systems

There are several VC systems out there.

To mention a few: PerForce, ClearCase, Visual SourceSafe, CVS and SubVersion.

There are pros & cons for each.

40Oct 2008

VC systems

In the following slides we'll use subversion as an example.

subversion is a popular open source program.

It is well documented, has a large user base and it's free.

41Oct 2008

Enter...

42Oct 2008

subversion

subversion is a version control system for Unix and Windows.

It is independent of any file system or file types to manage

It is easy to install

43Oct 2008

subversionsubversion comes in command line (shell)

mode.Most commands involve a single program: svn.

For ex:svn import ...svn checkout ...svn checkin ...svn export ...

44Oct 2008

subversion

There are many more commands in subversion.

They handle updates, conflicts, allow to see differences between versions.

The complete list is extensive but well documented.

45Oct 2008

subversion

There is also a GUI front-end for subversion.

This front-end is completely separate but closely integrated to the GUI.

It's name is TortoiseSVN. subversion will be installed if not

there.46Oct 2008

subversionDifferent people prefer different

things:Windows users may choose the GUI

front-end for subversion.Unix users may prefer the shell

environmentAPL users might prefer to stay in APLEither way the results will be the

same: better coordination!47Oct 2008

subversion: an exampleAssuming we have the following

workspace named ROBOTSROBOTS written in Dyalog:

It has 2 top level namespaces in which there are 5 (nested) namespaces:

- namespace Master: 2 namespaces- namespace Troopers: 3 namespaces

48Oct 2008

subversion: an example

workspace

Data game

Pound Robot1SDuck

Troopers

Master

There are 7 namespaces, 5 of which are nested

49Oct 2008

subversion: an example

We’ve seen the benefits of using text files for the namespaces:

- easier to visualize the code- easier to maintain- easier to share- no need to have the interpreter to

see it

50Oct 2008

subversion: an exampleWe will create the following folder

named \ROBOTSROBOTS involving Dyalog scripts:

It has 2 folders and 5 scripts:- folder Master: 2 scripts- folder Troopers: 3 scripts

51Oct 2008

subversion: an exampleTo create \ROBOTS we only need to:

use SALT's <Save> function to store the scripted namespaces to the \ROBOTS subfolders

52Oct 2008

subversion: an exampleFor example:To create \ROBOTS\Troopers\

Pound.dyalog we will simply ask <Save> to do it for you:

⎕SE.SALT.Save 'Troopers.Pound \ROBOTS\Troopers\Pound -convert'

54Oct 2008

subversion: an exampleYou then do the other namespaces:

⎕SE.SALT.Save 'Troopers.SDuck \ROBOTS\Troopers\SDuck -convert‘

⎕SE.SALT.Save 'Troopers.Robot1 \ROBOTS\Troopers\Robot1 -convert'

55Oct 2008

subversion: an exampleIf everything in a namespace has to be

SALTed you can do:

⎕CS 'Troopers’

⎕SE.SALT.Snap '\ROBOTS\Troopers –convert -makedir'

56Oct 2008

subversion: an exampleHere is the final result in Explorer

view:

57Oct 2008

subversion: an exampleAnd here is what 'Pound' looks like:

58Oct 2008

If we were to stop here (not use subversion) we could )SAVE the workspace as it would remember where everything (all the namespaces) is.

But we need to move them first to a repository.

Let’s carry on.Oct 2008 59

subversion: an example

subversion: an exampleWe first create a repository, here in \

MyRepository:

60Oct 2008

We then import our system (ROBOTS) into it:

subversion: an example

MyRepositoryRobots import

61Oct 2008

Our system is now in the repository and can be checked out by anyone able to access it.

This can be on the same machine or on the same network.

It can also be across the internet with proper credentials.

subversion: an example

62Oct 2008

The original source is no longer required.

We can get rid of it (or back it up )

subversion: an example

63Oct 2008

Next we checkout a copy to work with.subversion: an example

MyRepository

aplscripts

checkout

RoXots

We will put our working copy in \aplscripts:

64Oct 2008

There is another way to do this if we want to preserve the original location by checking out INTO it an empty repository to which we add the new material:

• svnadmin create \repo• svn co file:///repo C:\robots\troopers• svn add C:\robots\troopers\*

subversion: an example

65Oct 2008

We can now start working in APL.We have to make sure SALT is

enabled:

subversion: an example

66Oct 2008

We can also state where the working folder is.

Here we specify to use our \aplscripts folder:

subversion: an example

67Oct 2008

Afterwards, when we start Dyalog, SALT should be there:

subversion: an example

68Oct 2008

Our working directory should be set:

subversion: an example

69Oct 2008

We can now bring in scripts:

subversion: an example

70Oct 2008

And edit one of them (3 changes):

subversion: an example

72Oct 2008

After editing we are prompted to replace:

subversion: an example

73Oct 2008

We verify the changes have been made:

TortoiseSVN : an example

74Oct 2008

We can see in explorer that all is there:

subversion: an example

75Oct 2008

Restoring the original workspace

We can now go back to the original workspace to work from there:

)LOAD ROBOTS)CS Troopers[]SE.SALT.Load 'Troopers/Pound'now in updated script form

76Oct 2008

User InteractionsThey now look like this:

workspace Pound

Robot1

SDuckTroopers

Data

gameMaster

\aplscripts

77Oct 2008

Many users InteractionsThey now look like this:

User 1working on Pound

User 2working on Robot1

workspace Pound

Robot1

SDuckTroopers

Datagame

Master

workspace Pound

Robot1

SDuck Troopers

Datagame

Master

78Oct 2008

When we are happy with all the changes we can tell subversion to commit the changes we've made:

subversion: an example

MyRepository

aplscripts

Checkin

79Oct 2008

We keep making changes in APL...

subversion: an example

80Oct 2008

... and committing until happy:

subversion: an example

81Oct 2008

Finally, to produce a finished version we export to a folder we'll use to hold the entire project

subversion: an example

MyRepositoryRobotGame export

82Oct 2008

We can see in Explorer the new \RobotGame folder:

subversion: an example

83Oct 2008

TortoiseSVN

An integrated disk ExplorerGUI front-end for subversion

84Oct 2008

TortoiseSVN: an exampleUsing the same ROBOTS example:

85Oct 2008

TortoiseSVN: an example

We first create an empty repository, here in \MyRepository:

- right click on the folder wanted

- TortoiseSVN- Create repository

here...

86Oct 2008

Then we import our current system into it:

TortoiseSVN: an example

87Oct 2008

Our system is now in the repository and can be checked out by anyone able to access it.

This can be on the same machine or on the same network.

It can also be across the internet with proper credentials.

TortoiseSVN: an example

88Oct 2008

Next we checkout a copy to work with.

We will put our working copy in \aplscripts:

TortoiseSVN : an example

89Oct 2008

Start Dyalog, SALT should be there:

TortoiseSVN: an example

90Oct 2008

Our working directory should be set:

TortoiseSVN : an example

91Oct 2008

We can now bring in scripts:

TortoiseSVN : an example

92Oct 2008

And edit one of them:

TortoiseSVN : an example

93Oct 2008

And edit one of them:

TortoiseSVN : an example

94Oct 2008

We verify the changes have been made:

TortoiseSVN : an example

95Oct 2008

We can see in explorer that all is there:

TortoiseSVN : an example

96Oct 2008

We can also ask to see the differences

TortoiseSVN: an example

98Oct 2008

Here we are using the diff program:

TortoiseSVN: an example

99Oct 2008

When happy we commit the changes

TortoiseSVN: an example

100Oct 2008

Finally, to produce a finished version we export to a folder we'll use to hold the entire project

TortoiseSVN: an example

102Oct 2008

3

We can see in Explorer the new \Army folder:

TortoiseSVN : an example

103Oct 2008

Control Version environmentsWhatever environment suits best your

needs there is another alternative.

The APL alternative: drive svn from APL

This presumes subversion is installed of course!

104Oct 2008

105Oct 2008

Spice

It uses a special syntax to issue commands using SALT.

To use it start statements with ], e.g.]mycmd

This is a SALT tool.

106Oct 2008

Spice Utilities

To get a list of all available commands enter ‘]?’ in the session:

110Oct 2008

Spice SVN UtilitiesSome of those utilities relate to Version

Control.They are grouped under svn:

111Oct 2008

Spice SVN UtilitiesSyntax is similar to the command line versionOnly the names have been changed (slightly)

112Oct 2008

Spice: an exampleAssuming we have the following

project involving Dyalog scripts:

113Oct 2008

Spice: an example

And suppose we have a repository here

114Oct 2008

Then we import our current system into it:

Spice: an example

115Oct 2008

Our system is now in the repository and can be checked out by anyone able to access it.

Spice: an example

repository

checkout

subset

checkout

subset

subset

subset

checkoutcheckout

116Oct 2008

Next we checkout a copy to work with.

We will put our working copy in \aplscripts:

Spice : an example

117Oct 2008

svnco already sets up our working directory for us

Spice : an example

Confirmed by the settings command

118Oct 2008

We can now bring in scripts:

Spice: an example

119Oct 2008

And edit one of them (3 changes):

120Oct 2008

Spice: an example

After editing we are prompted to replace:

121Oct 2008

Spice: an example

When we are happy with all the changes we can tell subversion to commit the changes we've made.

Spice: an example

122Oct 2008

The use of svn under Spice is just another possibility.

The choice to use the shell commands, TortoiseSVN or Spice is a personal matter.

What is important is to ensure proper synchronisation between team members and subversion provides just that.

Conclusion

125Oct 2008

Wait, how do I use this?

Subversion and TortoiseSVN are available from the Net.

SALT/Spice come with Dyalog ready for use.

You will find on your memory stick a presentation on how to port an APL application into SALT.

126Oct 2008