Prolog - Write out facts and reading a users input
I am quite new to Prolog and have had some trouble understanding it.
I have some facts named 'problem' I wish to first print out these facts to the user and then ask them to input a value, this value is then read and used later.
From my understanding thus far, it would be best to use a forall to print out these facts and then use read to read the value inputted, but I am having some issue implementing this. Here is what I have so far, any explanation would be appreciated
My question: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
tellMeYourProblem:-
forall(problem(P),
writeln(P)),
answer = read(X),
problem('1').
problem('2').
problem('3').
problem('4').
problem('5').
problem('6').
problem('7').
problem('8').
problem('9').
problem('10').
prolog
add a comment |
I am quite new to Prolog and have had some trouble understanding it.
I have some facts named 'problem' I wish to first print out these facts to the user and then ask them to input a value, this value is then read and used later.
From my understanding thus far, it would be best to use a forall to print out these facts and then use read to read the value inputted, but I am having some issue implementing this. Here is what I have so far, any explanation would be appreciated
My question: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
tellMeYourProblem:-
forall(problem(P),
writeln(P)),
answer = read(X),
problem('1').
problem('2').
problem('3').
problem('4').
problem('5').
problem('6').
problem('7').
problem('8').
problem('9').
problem('10').
prolog
Of interest: Read–eval–print loop
– Guy Coder
Nov 15 '18 at 13:30
Of interest: RosettaCode Prolog Input/Output for Lines of Text
– Guy Coder
Nov 15 '18 at 13:34
I added the question into my post: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
– VicentVega
Nov 15 '18 at 13:53
add a comment |
I am quite new to Prolog and have had some trouble understanding it.
I have some facts named 'problem' I wish to first print out these facts to the user and then ask them to input a value, this value is then read and used later.
From my understanding thus far, it would be best to use a forall to print out these facts and then use read to read the value inputted, but I am having some issue implementing this. Here is what I have so far, any explanation would be appreciated
My question: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
tellMeYourProblem:-
forall(problem(P),
writeln(P)),
answer = read(X),
problem('1').
problem('2').
problem('3').
problem('4').
problem('5').
problem('6').
problem('7').
problem('8').
problem('9').
problem('10').
prolog
I am quite new to Prolog and have had some trouble understanding it.
I have some facts named 'problem' I wish to first print out these facts to the user and then ask them to input a value, this value is then read and used later.
From my understanding thus far, it would be best to use a forall to print out these facts and then use read to read the value inputted, but I am having some issue implementing this. Here is what I have so far, any explanation would be appreciated
My question: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
tellMeYourProblem:-
forall(problem(P),
writeln(P)),
answer = read(X),
problem('1').
problem('2').
problem('3').
problem('4').
problem('5').
problem('6').
problem('7').
problem('8').
problem('9').
problem('10').
prolog
prolog
edited Feb 14 at 20:59
false
11k772147
11k772147
asked Nov 15 '18 at 13:24
VicentVegaVicentVega
9618
9618
Of interest: Read–eval–print loop
– Guy Coder
Nov 15 '18 at 13:30
Of interest: RosettaCode Prolog Input/Output for Lines of Text
– Guy Coder
Nov 15 '18 at 13:34
I added the question into my post: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
– VicentVega
Nov 15 '18 at 13:53
add a comment |
Of interest: Read–eval–print loop
– Guy Coder
Nov 15 '18 at 13:30
Of interest: RosettaCode Prolog Input/Output for Lines of Text
– Guy Coder
Nov 15 '18 at 13:34
I added the question into my post: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
– VicentVega
Nov 15 '18 at 13:53
Of interest: Read–eval–print loop
– Guy Coder
Nov 15 '18 at 13:30
Of interest: Read–eval–print loop
– Guy Coder
Nov 15 '18 at 13:30
Of interest: RosettaCode Prolog Input/Output for Lines of Text
– Guy Coder
Nov 15 '18 at 13:34
Of interest: RosettaCode Prolog Input/Output for Lines of Text
– Guy Coder
Nov 15 '18 at 13:34
I added the question into my post: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
– VicentVega
Nov 15 '18 at 13:53
I added the question into my post: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
– VicentVega
Nov 15 '18 at 13:53
add a comment |
2 Answers
2
active
oldest
votes
Note: This answer uses SWI-Prolog.
How do I read in the input from the user regarding the problem?
You are doing that already with read(X)
, however read/1 reads terms (terms end with periods) and you probably want to read characters. If you are using SWI-Prolog take a look at Primitive character I/O for reading characters and Predicates that operate on strings for reading strings.
How do I apply that into a variable for later use?
When doing basic I/O with a user at a text level, a REPL is a good way to start. Adding a REPL is a bit more complicated so I will give you the code.
tellMeYourProblem :-
output_problems,
read_input.
output_problems :-
forall(problem(P),
writeln(P)).
read_input :-
repeat,
read_string(user_input, "n", "rt ", _, Line),
process_input(Line).
process_input(Line) :-
string(Line),
atom_number(Line, N),
integer(N),
do_something_with(Line),
fail.
process_input("quit") :-
write('Finished'), nl,
!, true.
do_something_with(X) :-
writeln(X).
problem('1').
problem('2').
problem('3').
problem('4').
problem('5').
problem('6').
problem('7').
problem('8').
problem('9').
problem('10').
Also with Prolog, the style is to use snake casing so tellMeYourProblem
should be tell_me_your_problem
.
Normally in Prolog a REPL is done with ->/2, (Read Input till quit statement Prolog) , but I changed this to add more guard statements so that the exit condition would work, e.g.
string(Line),
atom_number(Line, N),
integer(N)
or putting the guard in the head, e.g.
process_input("quit")
When doing I/O to a screen and keyboard, the thought is to use stdIn
and stdOut
but for the keyboard SWI-Prolog uses user_input
instead. See: Input and output
After all of the boiler plate code for the REPL is the next part you seek which is to do something with the input value, in this case just print it out.
do_something_with(X) :-
writeln(X).
add a comment |
The easiest to write out the facts of problem/1,
is to use the builtin listing/[0,1]. This builtin
accepts a so called predicate indicator. You can
write out the facts via:
?- listing(problem/1).
The predicate is supported by many Prolog systems
such as GNU Prolog, etc.. For how to read input see
for example the post by Guy Coder.
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
Note: This answer uses SWI-Prolog.
How do I read in the input from the user regarding the problem?
You are doing that already with read(X)
, however read/1 reads terms (terms end with periods) and you probably want to read characters. If you are using SWI-Prolog take a look at Primitive character I/O for reading characters and Predicates that operate on strings for reading strings.
How do I apply that into a variable for later use?
When doing basic I/O with a user at a text level, a REPL is a good way to start. Adding a REPL is a bit more complicated so I will give you the code.
tellMeYourProblem :-
output_problems,
read_input.
output_problems :-
forall(problem(P),
writeln(P)).
read_input :-
repeat,
read_string(user_input, "n", "rt ", _, Line),
process_input(Line).
process_input(Line) :-
string(Line),
atom_number(Line, N),
integer(N),
do_something_with(Line),
fail.
process_input("quit") :-
write('Finished'), nl,
!, true.
do_something_with(X) :-
writeln(X).
problem('1').
problem('2').
problem('3').
problem('4').
problem('5').
problem('6').
problem('7').
problem('8').
problem('9').
problem('10').
Also with Prolog, the style is to use snake casing so tellMeYourProblem
should be tell_me_your_problem
.
Normally in Prolog a REPL is done with ->/2, (Read Input till quit statement Prolog) , but I changed this to add more guard statements so that the exit condition would work, e.g.
string(Line),
atom_number(Line, N),
integer(N)
or putting the guard in the head, e.g.
process_input("quit")
When doing I/O to a screen and keyboard, the thought is to use stdIn
and stdOut
but for the keyboard SWI-Prolog uses user_input
instead. See: Input and output
After all of the boiler plate code for the REPL is the next part you seek which is to do something with the input value, in this case just print it out.
do_something_with(X) :-
writeln(X).
add a comment |
Note: This answer uses SWI-Prolog.
How do I read in the input from the user regarding the problem?
You are doing that already with read(X)
, however read/1 reads terms (terms end with periods) and you probably want to read characters. If you are using SWI-Prolog take a look at Primitive character I/O for reading characters and Predicates that operate on strings for reading strings.
How do I apply that into a variable for later use?
When doing basic I/O with a user at a text level, a REPL is a good way to start. Adding a REPL is a bit more complicated so I will give you the code.
tellMeYourProblem :-
output_problems,
read_input.
output_problems :-
forall(problem(P),
writeln(P)).
read_input :-
repeat,
read_string(user_input, "n", "rt ", _, Line),
process_input(Line).
process_input(Line) :-
string(Line),
atom_number(Line, N),
integer(N),
do_something_with(Line),
fail.
process_input("quit") :-
write('Finished'), nl,
!, true.
do_something_with(X) :-
writeln(X).
problem('1').
problem('2').
problem('3').
problem('4').
problem('5').
problem('6').
problem('7').
problem('8').
problem('9').
problem('10').
Also with Prolog, the style is to use snake casing so tellMeYourProblem
should be tell_me_your_problem
.
Normally in Prolog a REPL is done with ->/2, (Read Input till quit statement Prolog) , but I changed this to add more guard statements so that the exit condition would work, e.g.
string(Line),
atom_number(Line, N),
integer(N)
or putting the guard in the head, e.g.
process_input("quit")
When doing I/O to a screen and keyboard, the thought is to use stdIn
and stdOut
but for the keyboard SWI-Prolog uses user_input
instead. See: Input and output
After all of the boiler plate code for the REPL is the next part you seek which is to do something with the input value, in this case just print it out.
do_something_with(X) :-
writeln(X).
add a comment |
Note: This answer uses SWI-Prolog.
How do I read in the input from the user regarding the problem?
You are doing that already with read(X)
, however read/1 reads terms (terms end with periods) and you probably want to read characters. If you are using SWI-Prolog take a look at Primitive character I/O for reading characters and Predicates that operate on strings for reading strings.
How do I apply that into a variable for later use?
When doing basic I/O with a user at a text level, a REPL is a good way to start. Adding a REPL is a bit more complicated so I will give you the code.
tellMeYourProblem :-
output_problems,
read_input.
output_problems :-
forall(problem(P),
writeln(P)).
read_input :-
repeat,
read_string(user_input, "n", "rt ", _, Line),
process_input(Line).
process_input(Line) :-
string(Line),
atom_number(Line, N),
integer(N),
do_something_with(Line),
fail.
process_input("quit") :-
write('Finished'), nl,
!, true.
do_something_with(X) :-
writeln(X).
problem('1').
problem('2').
problem('3').
problem('4').
problem('5').
problem('6').
problem('7').
problem('8').
problem('9').
problem('10').
Also with Prolog, the style is to use snake casing so tellMeYourProblem
should be tell_me_your_problem
.
Normally in Prolog a REPL is done with ->/2, (Read Input till quit statement Prolog) , but I changed this to add more guard statements so that the exit condition would work, e.g.
string(Line),
atom_number(Line, N),
integer(N)
or putting the guard in the head, e.g.
process_input("quit")
When doing I/O to a screen and keyboard, the thought is to use stdIn
and stdOut
but for the keyboard SWI-Prolog uses user_input
instead. See: Input and output
After all of the boiler plate code for the REPL is the next part you seek which is to do something with the input value, in this case just print it out.
do_something_with(X) :-
writeln(X).
Note: This answer uses SWI-Prolog.
How do I read in the input from the user regarding the problem?
You are doing that already with read(X)
, however read/1 reads terms (terms end with periods) and you probably want to read characters. If you are using SWI-Prolog take a look at Primitive character I/O for reading characters and Predicates that operate on strings for reading strings.
How do I apply that into a variable for later use?
When doing basic I/O with a user at a text level, a REPL is a good way to start. Adding a REPL is a bit more complicated so I will give you the code.
tellMeYourProblem :-
output_problems,
read_input.
output_problems :-
forall(problem(P),
writeln(P)).
read_input :-
repeat,
read_string(user_input, "n", "rt ", _, Line),
process_input(Line).
process_input(Line) :-
string(Line),
atom_number(Line, N),
integer(N),
do_something_with(Line),
fail.
process_input("quit") :-
write('Finished'), nl,
!, true.
do_something_with(X) :-
writeln(X).
problem('1').
problem('2').
problem('3').
problem('4').
problem('5').
problem('6').
problem('7').
problem('8').
problem('9').
problem('10').
Also with Prolog, the style is to use snake casing so tellMeYourProblem
should be tell_me_your_problem
.
Normally in Prolog a REPL is done with ->/2, (Read Input till quit statement Prolog) , but I changed this to add more guard statements so that the exit condition would work, e.g.
string(Line),
atom_number(Line, N),
integer(N)
or putting the guard in the head, e.g.
process_input("quit")
When doing I/O to a screen and keyboard, the thought is to use stdIn
and stdOut
but for the keyboard SWI-Prolog uses user_input
instead. See: Input and output
After all of the boiler plate code for the REPL is the next part you seek which is to do something with the input value, in this case just print it out.
do_something_with(X) :-
writeln(X).
edited Feb 14 at 20:44
repeat
15.4k442138
15.4k442138
answered Nov 15 '18 at 15:18
Guy CoderGuy Coder
15.6k43985
15.6k43985
add a comment |
add a comment |
The easiest to write out the facts of problem/1,
is to use the builtin listing/[0,1]. This builtin
accepts a so called predicate indicator. You can
write out the facts via:
?- listing(problem/1).
The predicate is supported by many Prolog systems
such as GNU Prolog, etc.. For how to read input see
for example the post by Guy Coder.
add a comment |
The easiest to write out the facts of problem/1,
is to use the builtin listing/[0,1]. This builtin
accepts a so called predicate indicator. You can
write out the facts via:
?- listing(problem/1).
The predicate is supported by many Prolog systems
such as GNU Prolog, etc.. For how to read input see
for example the post by Guy Coder.
add a comment |
The easiest to write out the facts of problem/1,
is to use the builtin listing/[0,1]. This builtin
accepts a so called predicate indicator. You can
write out the facts via:
?- listing(problem/1).
The predicate is supported by many Prolog systems
such as GNU Prolog, etc.. For how to read input see
for example the post by Guy Coder.
The easiest to write out the facts of problem/1,
is to use the builtin listing/[0,1]. This builtin
accepts a so called predicate indicator. You can
write out the facts via:
?- listing(problem/1).
The predicate is supported by many Prolog systems
such as GNU Prolog, etc.. For how to read input see
for example the post by Guy Coder.
answered Nov 15 '18 at 17:26
Harry StotelesHarry Stoteles
293
293
add a comment |
add a comment |
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Of interest: Read–eval–print loop
– Guy Coder
Nov 15 '18 at 13:30
Of interest: RosettaCode Prolog Input/Output for Lines of Text
– Guy Coder
Nov 15 '18 at 13:34
I added the question into my post: How do I read in the input from the user regarding the problem and apply that into a variable for later use?
– VicentVega
Nov 15 '18 at 13:53