/* Read a sentence */

 :- mode initread(-).
 :- mode readrest(+,-).
 :- mode word(-,?,?).
 :- mode words(-,?,?).
 :- mode alphanum(+,-).
 :- mode alphanums(-,?,?).
 :- mode digits(-,?,?).
 :- mode digit(+).
 :- mode lc(+,-).

 :- module(readin,[read_in(1)]).

/* Read sentence */

read_in(P):-initread(L),words(P,L,[]),!.

initread([K1,K2|U]):-get(K1),get0(K2),readrest(K2,U).

readrest(46,[]):-!.
readrest(63,[]):-!.
readrest(33,[]):-!.
readrest(K,[K1|U]):-K=<32,!,get(K1),readrest(K1,U).
readrest(K1,[K2|U]):-get0(K2),readrest(K2,U).

words([V|U]) --> word(V),!,blanks,words(U).
words([]) --> [].

word(U1) --> [K],Elc(K,K1)L,!,alphanums(U2),Ename(U1,[K1|U2])L.
word(nb(N)) --> [K],Edigit(K)L,!,digits(U),Ename(N,[K|U])L.
word(V) --> [K],Ename(V,[K])L.

alphanums([K1|U]) --> [K],Ealphanum(K,K1)L,!,alphanums(U).
alphanums([]) --> [].

alphanum(K,K1):-lc(K,K1).
alphanum(K,K):-digit(K).

digits([K|U]) --> [K],Edigit(K)L,!,digits(U).
digits([]) --> [].

blanks--> [K],EK=<32L,!,blanks.
blanks --> [].

digit(K):-K>47,K<58.

lc(K,K1):-K>64,K<91,!,K1 is K\/8'40.
lc(K,K):-K>96,K<123.