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Truth table: Difference between revisions
→{{header|Tcl}}
(Add source for Rust) |
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true true true | true
</pre>
=={{header|Smalltalk}}==
{{works with|Smalltalk/X}}
<lang smalltalk>[:repeat |
expr := Stdin
request:'Enter boolean expression (name variables a,b,c...):'
defaultAnswer:'a|b'.
ast := Parser parseExpression:expr inNameSpace:nil onError:repeat.
"/ ensure that only boolean logic operations are inside (sandbox)
(ast messageSelectors asSet conform:[:each | #( '|' '&' 'not' ) includes:each]) ifFalse:repeat.
] valueWithRestart.
"/ extract variables from the AST as a collection
"/ (i.e. if user entered 'a & (b | x)', we get #('a' 'b' 'x')
varNames := StringCollection streamContents:[:s | ast variableNodesDo:[:each | s nextPut:each name]].
"/ generate a code for a block (aka lambda) to evaluate it; this makes a string like:
"/ [:a :b :x | a & (b | x) ]
code := '[' , ((varNames collect:[:nm | ':',nm]) asString), ' | ' , expr , ']'.
"/ eval the code, to get the block
func := Parser evaluate:code.
'Truth table for %s:\n' printf:{expr} on:Stdout.
'===================\n' printf:{} on:Stdout.
(varNames,{' result'}) do:[:each | '|%6s' printf:{each} on:Stdout].
Stdout cr.
Stdout next:(varNames size + 1)*7 put:$-.
Stdout cr.
"/ now print with all combinations
allCombinationsDo :=
[:remainingVars :valuesIn :func |
remainingVars isEmpty ifTrue:[
valuesIn do:[:each | '|%6s' printf:{each}on:Stdout].
'|%6s\n' printf:{ func valueWithArguments:valuesIn} on:Stdout.
] ifFalse:[
#(false true) do:[:each |
allCombinationsDo value:(remainingVars from:2)
value:(valuesIn copyWith:each)
value:func.
].
].
].
allCombinationsDo value:varNames value:#() value:func
</lang>
{{out}}
<pre>Enter boolean expression (name variables a,b,c...): [[a|b]]:
a&b|c
Truth table for (a&b)|x:
===================
| a| b| x| result
----------------------------
| false| false| false| false
| false| false| true| true
| false| true| false| false
| false| true| true| true
| true| false| false| false
| true| false| true| true
| true| true| false| true
| true| true| true| true</pre>
=={{header|Tcl}}==
| |||