static void EvaluateTruth(string[] args)
{
if (args.Length == 0)
{
throw new ArgumentException("Expected expression.");
}
var expression = string.Join(' ', args);
if (!LogicExpression.IsValid(expression, out string validationMessage))
{
Console.WriteLine($"Invalid expression: {validationMessage}");
return;
}
var argument = new LogicArgument();
foreach (var definition in Definitions)
{
argument.AddPremise(LogicExpression.Create(definition.Value));
}
argument.SetConclusion(LogicExpression.Create(expression));
Console.WriteLine(argument.IsValid());
var truthTableBuilder = new TruthTableBuilder();
truthTableBuilder.WriteTruthTable(LogicExpression.Create(argument.ToExpression()), new AsciiTruthTableWriter(Console.Out));
}
static void Define(string[] args)
{
if (args.Length == 0)
{
// Dump all variables.
foreach (var definition in Definitions)
{
var exp = LogicExpression.Create(definition.Value);
Console.WriteLine($"=> {definition.Key} = {definition.Value} ({exp.GetPropositionText()})");
}
return;
}
var temp = string.Join(' ', args);
var parts = temp.Split('=', StringSplitOptions.RemoveEmptyEntries);
if (parts.Length != 2)
{
throw new ArgumentException("Incorrect syntax. Expected: def [variable] = [expression].");
}
var variable = parts[0].Trim();
if (variable.IndexOf(' ') >= 0)
{
throw new ArgumentException("Variable name must not contain spaces.");
}
var expression = parts[1].Trim();
// Substitution
foreach (var definition in Definitions)
{
expression = expression.Replace(definition.Key, definition.Value, StringComparison.CurrentCultureIgnoreCase);
}
if (!LogicExpression.IsValid(expression, out string validationMessage))
{
Console.WriteLine($"Invalid expression: {validationMessage}");
return;
}
if (Definitions.ContainsKey(variable))
{
Definitions[variable] = expression;
}
else
{
Definitions.Add(variable, expression);
}
Console.WriteLine($"=> {variable} = {expression}");
}
static void PrintTruthTable(string[] args)
{
if (args.Length == 0)
{
throw new ArgumentException("Expected expression.");
}
var expressionSyntax = string.Join(' ', args);
if (!LogicExpression.IsValid(expressionSyntax, out string validationMessage))
{
Console.WriteLine($"Invalid expression: {validationMessage}");
return;
}
var expression = LogicExpression.Create(expressionSyntax);
var truthTableBuilder = new TruthTableBuilder();
truthTableBuilder.WriteTruthTable(expression, new AsciiTruthTableWriter(Console.Out));
}
static void PrintSubExpressions(string[] args)
{
if (args.Length == 0)
{
throw new ArgumentException("Expected expression.");
}
var expressionSyntax = string.Join(' ', args);
if (!LogicExpression.IsValid(expressionSyntax, out string validationMessage))
{
Console.WriteLine($"Invalid expression: {validationMessage}");
return;
}
var expression = LogicExpression.Create(expressionSyntax);
var subExpressions = expression.GetSubExpressions();
foreach (var subExpression in subExpressions)
{
Console.WriteLine($"=> {subExpression}");
}
}