LSE (programming language)

LSE (French: Langage symbolique d'enseignement) is a programming language developed at Supélec and Télémécanique from the late 1960s to the mid-1970s.[1][2][3][4] It is similar to BASIC, except with French-language instead of English-language keywords. It was derived from an earlier language called LSD, also developed at Supélec. It is most commonly said to be an acronym for Langage Symbolique d'Enseignement (Symbolic Teaching Language), but other expansions are also known (e.g. Langage de Sup-Élec, or the more cynical Langage Sans Espoir (hopeless language)).

This article is about the BASIC-like programming language. For the Forth-like programming language "LSE", see STOIC.

LSE originally flourished because being "interpreted", the "tokens" used were common to all languages and with a nationalized "editor", tokenized programs could be listed in any language. Obviously, the support from the French Ministry of National Education, was very important, but it declined as the ministry lost interest. It went through a number of revisions; earlier versions of LSE lacked full support for structured programming, later versions such as LSE-83 (aka LSE-1983) by Jacques Arsac added structured programming support, along with exception handling.[5] Even later revisions, such as LSE-2000, added more functionality, new types, new operators (NI, ET QUE, OU QUE and SELON-DANS-SINON), flow control commands, etc.

Code examples

99 Bottles (AFNOR Z 65-020)

 
  1*CHANSON DES 99 BOUTEILLES DE BIERE
  2*PASCAL BOURGUIGNON, 2003
 10 FAIRE 20 POUR N←99 PAS -1 JUSQUA 1
 20 &STROF(N)
 30 AFFICHER['IL EST TEMPS D’’ALLER AU MAGASIN.',/]
 40 TERMINER
100 PROCEDURE &STROF(N) LOCAL S1,S0;CHAINE S1,S0;S1←"S";S0←"S"
110 SI N=2 ALORS S0←"" SINON SI N=1 ALORS DEBUT S1←"";S0←"" FIN
120 AFFICHER[U,' BOUTEILLE',U,' DE BIERE SUR LE MUR.',/]N,S1
130 AFFICHER[U,' BOUTEILLE',U,' DE BIERE.',/]N,S1
140 AFFICHER['EN PRENDRE UNE, LA FAIRE PASSER.',/]
150 AFFICHER[U,' BOUTEILLE',U,' DE BIERE SUR LE MUR.',2/]N-1,S0
160 RETOUR

Anagrams (LSE-1983)

Example from Jacques Arsac in LSE83:[5]

1 CHAINE A,B,BP
5 FAIRE
10 AFFICHER 'A = ' ;LIRE A ; SI A=’’ ALORS FINI IS
11 AFFICHER 'B = ' ;LIRE B ; BP ← B
12
15 R SI LGR(A) # LGR(B) ALORS .FAUX. SINON &ANAG(A,B) IS
20 SI R ALORS AFFICHER A, 'EST ANAGRAMME DE ',BP
21 SINON AFFICHER A, 'N’’EST PAS ANAGRAMME DE 1, BP
22 IS
25 BOUCLER
29
30 TERMINER
31
50 FONCTION &ANAG(U,V) LOCAL J {lgr(u)=lgr(v)}
51 SI U=' ' ALORS RESULTAT .VRAI. IS
52 SI J = 0 ALORS RESULTAT .FAUX. IS
54 RESULTAT &ANAG(SCH(U,2, ' '),MCH(V,J,l, ' '))
$55 &ANAG
$99

Largest common divisor, Euclid's algorithm (LSE2000)

 
(*
** MÉTHODE D'EUCLIDE POUR TROUVER LE PLUS GRAND DIVISEUR COMMUN D'UN
** NUMÉRATEUR ET D'UN DÉNOMINATEUR.
** L. Goulet 2010
*)
PROCÉDURE &PGDC(ENTIER U, ENTIER V) : ENTIER LOCAL U, V
   ENTIER T
   TANT QUE U > 0 FAIRE
       SI U< V ALORS
           T←U
           U←V
           V←T
       FIN SI
       U ← U - V
   BOUCLER
   RÉSULTAT V
FIN PROCÉDURE

PROCÉDURE &DEMO(ENTIER U, ENTIER V) LOCAL U, V
   AFFICHER ['Le PGDC de ',U,'/',U,' est ',U,/] U, V, &PGDC(U,V)
FIN PROCÉDURE

&DEMO(9,12)

References
  1. Hebenstreit, Jacques (2006). "The '10,000 microcomputers plan' in France". In Jacquetta Megarry (ed.). World Yearbook of Education 1982/3: Computers and Education. Routledge. p. 126. ISBN 978-1-136-16772-0. The language LSE (Langage Symbolique d'Enseignement–a symbolic teaching language) was defined at my laboratory in 1971 and implemented on the MITRA 15 and T1600, both French-made systems.
  2. Pascal Marquet (2004). Informatique et enseignement: progrès ou évolution? (in French). Editions Mardaga. p. 19. ISBN 978-2-87009-875-2.
  3. Héctor Schmucler (1997). Memoria de la comunicación (in Spanish). Editorial Biblos. p. 178. ISBN 978-950-786-141-3.
  4. "La Saga du LSE et de sa famille (LSD/LSG/LST)", by Yves Noyelle, May 1988. http://www.epi.asso.fr/revue/54/b54p216.htm (in French) "Toutes ces contraintes ont mené entre Mars 1968 et Mars 1969 à la conception de LSD ... La saga du LSE suit celle du LSD, et son origine est le colloque CERI/OCDE de Sèvres (mars 1970) ... Les gens de Télémécanique mirent le paquet sur ce projet ... et livrèrent deux systèmes fin Octobre 1972. ... Le développement des LSx s'est étendu sur neuf années (1968-1976), avec quelques interruptions."
  5. Arsac, Jacques (1985). "LSE 83" (PDF). Bulletin de l'EPI (in French) (38): 116–137.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.