Here is a presentation I created quite a few years back when giving a presentation to students on programming languages. I have updated it with some recent trends.

1. Programming languages
Trends in software development
Ganesh Samarthyam
sgganesh@gmail.com

2. Agenda
n Why languages matter
n Language popularity
n Domain Specific Languages
(DSLs)
¡ Case study: LaTeX
n New and emerging languages
¡ Case study: Go language
n Learning new languages
n That’s it!

3. Why languages matter?
n There are numerous languages in the
programming world
¡ See list of 2500 languages in
http://people.ku.edu/~nkinners/LangList/Extras/
langlist.htm
n Hundreds of languages released every year!
¡ Well-known recent languages include Go, Scala,
and Clojure languages
n People are passionate about languages
¡ Sometimes even emotional

4. Languages in programmer’s life
n Languages have special place in
programmer’s life
¡ Unlike “gizmos” or “technologies”
¡ We use languages on day-to-day basis
¡ Languages we use shapes our thoughts
n Programming is a creative activity
¡ that separates computer science from other
engineering disciplines
¡ Learning programming is not just about
learning the language features
n it is more about creative problem solving using
the existing features

5. Example: Creativity in Programming

6. Sierpinski triangle fractal!
n The word ‘fractal’ was
coined by a
mathematician named
Mandelbrot in 1975.
n Fractals are created
based on some simple
patterns and simple
rule(s).
n This program creates
Sierpinski triangle fractal
by printing @ and .
characters to the console!

7. Programming languages and research
n Approx 50% of Turing award winners closely
associated with programming or languages
¡ Turing award is highest award in CS
¡ Dijkstra & Peter Naur (Algol)
¡ Backus (Fortran)
¡ Iverson (APL)
¡ Ritchie (C)
¡ Dahl & Nygaard (Simula)
¡ Alan Kay (Smalltalk)
¡ …

9. Power of a language!
n Which language is more powerful?
¡ C, Pascal, Fortran, Assembly or Basic?
n A meaningless question!
¡ Fundamentally, languages are equally powerful
n But languages differ in their ability to perform
some specific tasks easier!
¡ By providing different language features or same
language features in different ways

10. A simple example: String replacement
n Simple string rewriting based on a set of
rules.
n An interesting application
¡ Converting a binary to unary by string
replacement by applying a set of rules.
n So what’s the big deal?
¡ This algorithm is shown to be “Turing
complete”!

11. Markov’s string replacement algorithm
Let us see the rules first:
Rule 1: "#0" => "0##"
Rule 2: "1" => "0#"
Rule 3: "0" => ""
Rule 4: "#" => "1"
Input string: "11"
Step 1: "0#1" (apply rule 2)
Step 2: "0#0#" (apply rule 2)
Step 3: "00###" (apply rule 1)
Step 4: "0###" (apply rule 3)
Step 5: "###" (apply rule 3)
Step 6: "1##" (apply rule 4)
Step 7: "11#" (apply rule 4)
Step 8: "111" (apply rule 4)
Terminate.
"100"
=> "0#00"
=> "00##0"
=> "00#0##"
=> "000####"
=> "00####"
=> "0####"
=> "####"
=> "1###"
=> "11##"
=> "111#"
=> "1111"

12. Language influence and evolution
n A new language is not created from
nowhere
¡ It is influenced by many other languages,
technologies or ideas
n Language evolution tree
¡ Graphical representation of how
languages are influenced by others
¡ Almost all here know C; but do you know
how many languages it got influenced
from?

13. Language popularity
n Many languages have started getting more
popular
¡ Those were relatively unknown in just recent past
¡ E.g. Ruby, Python, Lua, …
n How to we know the popularity of a language?
¡ Tiobe “language popularity index” is most widely
referred (http://www.tiobe.com/)
¡ Latest status is in next slide

14. TIOBE Index (as on Jan 2016)

15. Language popularity …
n Popularity depends on so many factors
¡ Like company sponsorship/backing
n Best example is Swift
¡ It is popular because of Apple
¡ Does it solve new problems or changes in the world
around us
n For example, Java became popular when released in 1995
because of web
n Concurrent languages will become popular because of multi-
core processors
¡ …

16. Language popularity: Observations
n C is the second most popular language!
¡ And its >3 decades old
¡ Continues to be popular for embedded programming
n C++ is steadily losing popularity
¡ C#, Java, etc ate from C++ pie
n Popular company related languages
¡ ActionScript (Adobe), C# (MS), Obj-C & Swift
(Apple)
n OO languages are very popular (55%)
¡ Procedural languages (40%)
¡ Functional, logic and other languages (5%)

17. Language popularity: Observations
n Statically typed languages are very popular (57%
share)
¡ Losing steadily to dynamic languages (42%)
n Web is becoming more & more pervasive
¡ PHP popularity reflects that
n Scripting languages are more popular than ever
before
¡ Loser: Perl; Gainers: Python & Ruby
n Non-GC languages losing popularity
¡ C++, Cobol, Fortran etc; except for C

18. Domain Specific Languages (DSLs)
n Surprisingly general purpose languages (like C,
Java…) are not best languages for specific uses
¡ Domain Specific Languages (DSLs) are best suited
for specific uses
n DSLs are about a specific domain, and provides
solutions for that domain
¡ E.g.: HTML, SQL, LaTeX, GraphViz, VHDL Verilog…
¡ The main problem is the time taken to learn
n and become productive

19. DSL Case study: LaTeX
n I’ve written full-length books using MS Word
¡ Bitten by the problems in managing a large
document
¡ MS Word not well suited for a specific purpose
like writing a book
n LaTeX is a markup language for document
preparation
¡ Like writing papers, letters, articles, thesis …
¡ Its macros on top of TeX (created by D.Knuth)

20. LaTeX vs. MS Word
n Can you find which document is created
with LaTeX and with MS Word?
MS Word LaTeX

21. Sample LaTeX program
documentclass[12pt]{article}
begin{document}
centering{
textbf{Hello world!}
}
end{document}
$ latex hello
$ dvips hello
$ gv hello.ps
$ ps2pdf hello.ps

22. The best programming language?
n Most of the programmers know which is the
best programming language.
¡ Each programmer has different answer!
¡ “the most favourite” is not “the best”
It is C you
know – there is
nothing like
that
Python! Its so intuitive
to program in it
its PHP - I think you
haven't used it – if you
use it you'll agree that
its the best

23. New and emerging languages
n The computing world is changing fast
¡ Old languages (C, Fortran…) are not very suitable
n Major trends
¡ More pervasive web/internet
¡ Multi-core processors
¡ Larger and more complex software
¡ Need for more reusable/pluggable software
¡ Wider use of embedded systems
¡ Reliability more important (e.g. s/w in pacemaker
device)
¡ ...

24. What are the new languages?
n Many new languages getting designed
with this new world order in mind
¡ Scala, Go, Swift etc
n General trend in new languages
¡ Garbage collected, concurrent, more
dynamic, higher-level, …
¡ Less importance for efficiency, OO, …
n Case study: Go language

25. Go: Background
n Go is from Google (Sep 09)
¡ Created lots of excitement in the programming community
n Many tout it as the next C language
¡ ‘C’ evolved from ‘B’; many languages are named as ‘D’, or
want to be the ‘D’ language
¡ But nothing has made the cut so far; “Go” might (or will it be
“Gone” in a few years ;-) )
n Go won Tiobe’s ‘language of the year award 2009’
n Robert Griesemer, Ken Thompson (of Unix fame), and Rob
Pike are the creators of the language.
¡ All three are well-known in programming community

26. Go: Important characteristics
n Simplicity: Go has a clean and concise syntax
¡ Characteristic of Google products
¡ For example, light-weight type system
n Use it to believe it
n Separation of interface and the implementation
¡ I know it’s often misused statement, but Go has it!
¡ Arguably a novel feature of Go
n Goroutines
¡ Is based on CSP: much safer than lock-based, like Java
n And more:
¡ E.g. Reflection (yes! but this is systems prog. lang!)

27. Go Interfaces: A novel feature
n Interfaces specified with
‘interface’ keyword
¡ Not same as in C#/Java
n The structs doesn’t
have to say it
implements an interface
¡ Any struct that
implements the methods
as specified by any
interface satisfies that
interface
¡ Strict static type checking
& “duck typing”!

28. Learning new languages
n Its worth learning new languages
¡ New ways of thinking or solving problems
¡ ‘As I write a program, I should use a
language that minimizes the distance
between the problem solving strategies
that I have in my head and the program
text I eventually write on paper’
- Jon Bentley (Programming Pearls)
n Go beyond learning the mainstream
languages
¡ Take the road less travelled!

29. Wrapping up
n Programming languages is an exciting
topic
¡ From research as well as practical usage
perspectives
n Consider learning a new language
¡ New like Swift, Scala, Go, Clojure …
¡ Or different ones like Lisp, Prolog,
Python, LaTeX…