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-rw-r--r--read.pro52
1 files changed, 52 insertions, 0 deletions
diff --git a/read.pro b/read.pro
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+
+
+% functions for obtaining a line of input text and parsing
+% it into a list of words
+
+% prompt provides the user with a '>' prompt as well
+% readList merely obtains and parses the input
+
+
+prompt(L) :-
+ write('> '),
+ readList(L).
+
+
+readList(L) :-
+ readLine(X),
+ wordList(L,X,[]), !.
+
+
+readLine(L) :-
+ get0(C),
+ buildList(C,L).
+
+
+buildList(10,[]) :- !.
+buildList(C,[C|X]) :-
+ get0(C2),
+ buildList(C2,X).
+
+
+wordList([X|Y]) --> word(X), whitespace, wordList(Y).
+wordList([X]) --> whitespace, wordList(X).
+wordList([X]) --> word(X).
+wordList([X]) --> whitespace, word(X).
+
+
+word(W) --> charList(X), {name(W,X)}.
+
+
+charList([X|Y]) --> char(X), charList(Y).
+charList([X]) --> char(X).
+
+
+char(X) --> [X], {X>=33}.
+
+
+whitespace --> whsp, whitespace.
+whitespace --> whsp.
+
+
+whsp --> [X], {X<33}.
+