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![A LITTLE STORY
Dimitri Fontaine aka @tapoueh
a PostgreSQL expert and Lisper-friendly
loads data into PostgreSQL fastpgloader
"I switched from Python to Common Lisp
because I wanted to use a modern
language" - @tapoueh
7th European Lisp Symposium
More than 20x faster than the previous Python version [1]](https://image.slidesharecdn.com/introduction-to-lisp-160314161440/75/Gentle-Introduction-To-Lisp-3-2048.jpg)
![MACROS BY EXAMPLE
Make a list as Python does:
seq = []
for elt in range(10):
if elt % 2 == 0:
seq.append(elt)
# use comprehension list
seq = [x for x in range(10) if x % 2 == 0]
Comprehension Lists
And you want to implement this feature in Common Lisp](https://image.slidesharecdn.com/introduction-to-lisp-160314161440/75/Gentle-Introduction-To-Lisp-23-2048.jpg)
Uploaded byDamien Garaud
Gentle Introduction To Lisp
This document provides an introduction to the Lisp programming language. It discusses the history of Lisp, which was created in 1958. It also covers key Lisp concepts like S-expressions, atoms, function definition, evaluation, and macros. Macros allow programmers to generate Lisp code from Lisp code, extending the language. The document uses examples to demonstrate Lisp evaluation and features like conditional evaluation, higher-order functions, and special forms like 'quote and 'if.
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Gentle Introduction To Lisp
- 1. (GENTLE) INTRODUCTION TOLISP Functional Programming Meetup Bordeaux – Node 2016-03-30 Damien Garaud / @jazzydag
- 2. WHO AM I? DamienGaraud Scientist Programmer Trainer & learning-addict @jazzydag https://github.com/garaud
- 3. A LITTLE STORY DimitriFontaine aka @tapoueh a PostgreSQL expert and Lisper-friendly loads data into PostgreSQL fastpgloader "I switched from Python to Common Lisp because I wanted to use a modern language" - @tapoueh 7th European Lisp Symposium More than 20x faster than the previous Python version [1]
- 4.
- 5. TINY DEMO It's gonnabe legen... wait for it M‐x irony‐mode
- 6. HISTORY 1958 John McCarthyMIT LISP: LISt Processing Not "Lots of Irritating and Silly Parentheses" 1970: Lisp Machines Artificial Intelligence 1980: need for standardization (Common Lisp) 1994: ANSI Common Lisp
- 7. WHICH LISP? Common Lisp Scheme(1970) Emacs Lisp (1976) Racket (1996) Arc (2001 Paul Graham) Clojure (2007 JVM) LFE as Lisp Flavored Erlang (2008 BEAM) Hylang (2013 Lisp & Python)
- 8. LANGUAGES FEATURES Dynamic Typing Functional& Imperative High-order Functions Object-oriented Prefix (polish) Notation Macros Garbage Collector Source as a data structure ... of course, it's just a list
- 9. S-EXPRESSION List () oran atom Each element is separated by a whitespace An element can be: a list an atom
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- 12. FUNCTION DEFINITION defun keyword (defun hello (name) "print hello" (format t "Hello ~a!~%" name)) (hello "lambda meetup") Thisis a S-expression with two nested S-exprs, 4 symbols, two strings and one boolean
- 13. EVALUATION: HOW DOESIT WORK Just read the S-expression Valid S-expression Valid Lisp expression Suppose the first element is a function or an operator Left to the right Evaluate all but first, then apply the first
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- 16. RETURNED VALUE The lastS-expression (if (zerop 0) (+ 5 3) (* 2 2)) Which value? 8
- 17. "IF" AND THESTANDARD EVALUATION RULE (if (zerop 0) (+ 1 3) (* 3 2)) Can you see the problem? Special operators Not really evaluated as usual
- 18. NOT ALWAYS EVALUATION Yousaw the if. What's else? (+ 2 5) (let ((a 2) (b 21)) (* a b)) Variables evaluation: it's OK What about the high-order functions You want to pass a name of a function Not evaluate me please
- 19. HIGHER-ORDER FUNCTIONS (defun algo (pred struct) "docstring" (impl)) (algo pred (list "coltrane" "davis" "hancock")) pred shouldn'tbe evaluated as is variable name error Special "quote"
- 20. SPECIAL QUOTE There isa function for that: (quote (a b c d)) (defun mypred (lhs rhs) "my predicate func" (> lhs rhs)) (algo (quote mypred) struct) special ' syntax (algo 'mypred struct)
- 21. TAKE A BREATH Whatdid we see: Evaluation rules S-expressions, S-expressions everywhere! Source code as a data structure (defun foo (arg) (body)) is a S- expression Thus arg can be a simple list or... ... a function definition Don't worry... the end is coming
- 22. MACROS It's about codegeneration ... but not really like C macros The programmable programming language
- 23. MACROS BY EXAMPLE Makea list as Python does: seq = [] for elt in range(10): if elt % 2 == 0: seq.append(elt) # use comprehension list seq = [x for x in range(10) if x % 2 == 0] Comprehension Lists And you want to implement this feature in Common Lisp
- 24. MACROS BY EXAMPLE (lcomp x for x in (range 10) if (= (mod x 2) 0)) Youcan define your own language extension (defmacro lcomp (expression for var in list cond condtest) "doc here" (body)) Lisp code generation writing Lisp code
- 25. FURTHER CLOS: Common LispObject System Quicklisp: a package manager Compilation: SBCL or Clozure CL Make a Lisp
- 26. REFERENCES SICP The Little Schemer PracticalCommon Lisp Common Lisp Recipes
- 27.