This is a talk comparing the language philosophies of Erlang, LFE, Joxa and Elixir: the languages which target the erlang virtual machine (BEAM).

1. ERLANG,
LFE,
JOXA &
ELIXIR
Established
and
Emerging
Languages in
the Erlang
Ecosystem

2. Let’s talk about computers.

3. many
processors

4. in a
network

5. inside an
even
bigger
network

6. and none
of it’s
reliable

7. and also
it’s spread
across the
globe

8. Our challenge as
engineers is to hide
the complicated
details of all of this.

9. Let’s talk about Erlang.
BEAM

10. Bogdan/jörn’s
Erlang
Abstract
Machine

11. Concurrent

12. Concurrent
Soft Real-Time

13. Concurrent
Soft Real-Time
Throughput Optimized

14. Concurrent
Soft Real-Time
Throughput Optimized
Embeddable

15. So we should all
start using Erlang
right away, yes?

16. Well…

17. Let’s talk about style.

18. Miles Davis

19. Miles Davis
cool

20. Miles Davis
cool
spare

21. Miles Davis
cool
spare
deliberate

22. Miles Davis
cool
spare
deliberate
flawless

23. Miles Davis
Sought to make
an individual,
new sound.

24. John
Coltrane

25. John
Coltrane
avant guard

26. John
Coltrane
avant guard
complex

27. John
Coltrane
avant guard
complex
chaotic

28. John
Coltrane
avant guard
complex
chaotic
blemished

29. John
Coltrane
Sought the
transcendent
through music.

30. Thelonious
Monk

31. Thelonious
Monk
unorthodox

32. Thelonious
Monk
unorthodox
eccentric

33. Thelonious
Monk
unorthodox
eccentric
discordant

34. Thelonious
Monk
unorthodox
eccentric
discordant
perfect

35. Thelonious
Monk
Made music
like a fish
swims in
water

36. I’m going to
compare
programming
languages.

37. These
languages
are not so
dissimilar.

38. This is not a
life or death
matter.

39. This is a
matter of right
tool, right job.

40. Every language has an intrinsic
philosophy of “good software”.

41. The language
designers’ choices
influence what a
language is most
naturally useful for.

42. Sometimes a design
goal is explicit.

43. Erlang

44. Soft real-time,
concurrent and
fault tolerant
systems.

45. Subsystems may
fail but the
service as a
whole remains
online.

46. Failures cause
sub-system
restarts.

47. Restarts put the
system back in a
well-known state:
prefer faults over
error handling.

48. Let it crash!

49. Language features make
crashes more likely.

50. Pattern Matching
No assignments:

51. Failed matches
cause crashes.

52. Process
Linking

53. Faults cascade up the
process hierarchy.

54. Traps exist to survive
child crashes but they
are not on by default.

55. Strict process
isolation.

56. State changes are effected
only through message
passing.

57. Processes are sequential
internally, concurrent to one
another.

58. LFELisp Flavored Erlang

59. Maintains
semantic
equivalence to
Erlang.

60. Lisp-2, Macros
&
Homoiconicity

61. A REPL,
not just a
shell.

62. Erlang,
in Lisp
Clothing

63. Let it crash!

64. Joxa

65. Lisp-1, Macros
&
Homoiconicity

66. A lisp that
happens
to run on
BEAM

67. Elixir

68. Solves the
“Expression”
problem

69. Protocols

70. Streams /
Iterables

71. Infix
Operators

72. Multiple function
invocation styles

73. Metaprogramming

74. Multi-Assignments

75. Pattern Matching is non-
default. Must use a prefix
character to match.

76. Defaults
callbacks
for OTP
Behaviours

77. Which of these languages
are production ready?

78. What’s your risk
tolerance?

79. LFE
367 commits
August 22, 2008
updated weekly
14 contributors

80. Joxa
470 commits
November 25, 2011
updated monthly
8 contributors

81. Elixir
7618 commits
January 9, 2011
updated daily
168 contributors

82. Erlang
14,273 commits
Estd.1986
updated daily
227 contributors

83. Complexity

84. Complexity
Erlang

85. Complexity
Erlang LFE

86. Complexity
Erlang ElixirLFE

87. Software projects go
through three stages:
!
• exploration
• stable development
• maintenance

88. Experimentation
Stable Development
Maintenance

89. Different phases
of the life-cycle
express different
needs.

90. Experimental:
“Move fast,
break stuff.”

91. Stable:
“Go fast and
mostly work.”

92. Maintenance:
“Move slow,
build things.”

93. “Expressivity”,
which is a boon while
prototyping, can be
a curse in more
stable environments.

94. “Intentional”
languages may be
too cumbersome in
an environment of
complete unknowns.

95. Complexity
Erlang ElixirLFE

96. C++
Erlang
ElixirLFE

97. None of the BEAM
languages abandon
what makes Erlang
great (especially
not Erlang).

98. Elixir targets the
experimental,
very beginnings
of stable.

99. LFE targets the
tail end of
experimental,
beginning to mid of
stable.

100. Erlang is a stable
and maintenance
stage sort of
language.

101. Experimentation
Stable Development
Maintenance

102. Elixir
LFE
Erlang

103. Questions?
<3

104. Thank you!
@bltroutwine