Truth table: Difference between revisions
Add SETL
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</pre>
=={{header|SETL}}==
<syntaxhighlight lang="setl">program truth_table;
exprstr := "" +/ command_line;
if exprstr = "" then
print("Enter a Boolean expression on the command line.");
else
showtable(exprstr);
end if;
proc showtable(exprstr);
if (toks := tokenize(exprstr)) = om then return; end if;
if (bexp := parse(toks)) = om then return; end if;
vars := [v : v in getvars(bexp)]; $ fix the variable order
$ show table header
tabh := "";
loop for v in vars do
tabh +:= v + " ";
end loop;
print(tabh +:= "| " + exprstr);
print('-' * #tabh);
$ show table rows
loop for inst in instantiations(vars) do
loop for v in vars do
putchar(rpad(showbool(inst(v)), #v) + " ");
end loop;
print("| " + showbool(booleval(bexp, inst)));
end loop;
end proc;
proc showbool(b); return if b then "1" else "0" end if; end proc;
proc instantiations(vars);
insts := [];
loop for i in [0..2**#vars-1] do
inst := {};
loop for v in vars do
inst(v) := i mod 2 /= 0;
i div:= 2;
end loop;
insts with:= inst;
end loop;
return insts;
end proc;
proc booleval(tokens, inst);
stack := [];
loop for token in tokens do
case token of
("~"): x frome stack; stack with:= not x;
("&"): y frome stack; x frome stack; stack with:= x and y;
("|"): y frome stack; x frome stack; stack with:= x or y;
("^"): y frome stack; x frome stack; stack with:= x /= y;
("=>"): y frome stack; x frome stack; stack with:= x impl y;
("0"): stack with:= false;
("1"): stack with:= true;
else stack with:= inst(token);
end case;
end loop;
answer frome stack;
return answer;
end proc;
proc getvars(tokens);
return {tok : tok in tokens | to_upper(tok(1)) in "ABCDEFGHIJKLMNOPQRSTUVWXYZ_"};
end proc;
proc parse(tokens);
ops := {["~", 4], ["&", 3], ["|", 2], ["^", 2], ["=>", 1]};
stack := [];
queue := [];
loop for token in tokens do
if token in domain ops then
loop while stack /= []
and (top := stack(#stack)) /= "("
and ops(top) > ops(token) do
oper frome stack;
queue with:= oper;
end loop;
stack with:= token;
elseif token = "(" then
stack with:= token;
elseif token = ")" then
loop doing
if stack = [] then
print("Missing (.");
return om;
end if;
oper frome stack;
while oper /= "(" do
queue with:= oper;
end loop;
elseif token(1) in "23456789" then
print("Invalid boolean ", token);
return om;
else
queue with:= token;
end if;
end loop;
loop while stack /= [] do
oper frome stack;
if oper = "(" then
print("Missing ).");
return om;
end if;
queue with:= oper;
end loop;
return queue;
end proc;
proc tokenize(s);
varchars := "abcdefghijklmnopqrstuvwxyz";
varchars +:= to_upper(varchars);
varchars +:= "0123456789_";
tokens := [];
loop doing span(s, " \t\n"); while s /= "" do
if (tok := any(s, "()&|~^")) /= "" $ brackets/single char operators
or (tok := match(s, "=>")) /= "" $ implies (=>)
or (tok := span(s, "0123456789")) /= "" $ numbers
or (tok := span(s, varchars)) /= "" $ variables
then
tokens with:= tok;
else
print("Parse error at", s);
return om;
end if;
end loop;
return tokens;
end proc;
end program;</syntaxhighlight>
{{out}}
<pre>$ setl truth.setl '(human=>mortal) & (socrates=>human) => (socrates=>mortal)'
human mortal socrates | (human=>mortal) & (socrates=>human) => (socrates=>mortal)
---------------------------------------------------------------------------------
0 0 0 | 1
1 0 0 | 1
0 1 0 | 1
1 1 0 | 1
0 0 1 | 1
1 0 1 | 1
0 1 1 | 1
1 1 1 | 1</pre>
=={{header|Sidef}}==
| |||