Re^2: Generate a truth table from input string

Parsing is quite possibly not required. Assuming that the variables can be assumed to contain a true value why not just leverage perl.

$str =~ s/\*/&&/g;
$str =~ s/\+/||/g;
# $str =~ s/'/!/g;
$str =~ s/(\w+)'/!$1/g;
$str =~ s/\(([^\)]+)\)'/!($1)/g;
$str =~ s/\w+/1/g;
my $truth = eval $str;
[download]

If the a/b/A/B vars have associated values all that is required is to substitute them in. Perl does the parsing and calculates the truth.

Update

Modified to deal with ' postfix syntax

Comment on Re^2: Generate a truth table from input string Download Code

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Re^3: Generate a truth table from input string by ikegami (Patriarch) on May 13, 2008 at 16:43 UTC
`$str =~ s/'/!/g;` [download] is not sufficient to convert a postfix operator to a prefix operator. `"a'"` produces the invalid code `"1!"`.	[reply] [d/l] [select]
Re^4: Generate a truth table from input string by tachyon-II (Chaplain) on May 13, 2008 at 18:40 UTC
`$str =~ s/(\w+)'/!$1/g; $str =~ s/$([^$]+)\)'/!($1)/g;` [download]	[reply] [d/l]
Re^5: Generate a truth table from input string by ikegami (Patriarch) on May 13, 2008 at 18:43 UTC
It you're going to allow `(a+b)'` — the OP might be happy with only supporting `/\w+'/` — you must allow `(a*(b+c))'` too. Other than that, there are a few other problems. ~~You don't handle xor~~, you assume the same precedence and associativity as Perl, and you don't generate a truth table. I presume that's intentional and that you're leaving those as an exercise to the reader, so I'm just documenting what's left to do.	[reply] [d/l] [select]
Re^6: Generate a truth table from input string by tachyon-II (Chaplain) on May 14, 2008 at 00:30 UTC
Re^7: Generate a truth table from input string by Anonymous Monk on Oct 28, 2017 at 11:46 UTC
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