private static void TestVariousExpressions()
{
string[][] expressions = {
// infix, value, prefix, postfix, AST
new[] { "2", "2", "2", "2", "2" },
new[] { "-2", "-2", "- 2", "2 -", "-(2)" },
new[] { "-2 + 5", "3", "+ - 2 5", "2 - 5 +", "+(-(2), 5)" },
new[] { "2 + 5 * 7", "37", "+ 2 * 5 7", "2 5 7 * +", "+(2, *(5, 7))" },
new[] { "-(2 + 5) * 7", "-49", "* - + 2 5 7", "2 5 + - 7 *", "*(-(+(2, 5)), 7)" },
new[] { "1 ^ 2 ^ 3", "1", "^ 1 ^ 2 3", "1 2 3 ^ ^", "^(1, ^(2, 3))" },
};
foreach (string[] e in expressions) {
int value = new InfixEvaluatorParser(new ExpressionLexer()).Parse(e[0]);
Token prefix = new InfixToPrefixParser(new ExpressionLexer()).Parse(e[0]);
Token postfix = new InfixToPostfixParser(new ExpressionLexer()).Parse(e[0]);
Expression expression = new InfixToAbstractSyntaxTreeParser(new ExpressionLexer()).Parse(e[0]);
FlatExpressionPrinter printer = new FlatExpressionPrinter();
if (e[1] != value.ToString() &&
e[1] != expression.Evaluate().ToString() &&
e[2] != prefix.Lexeme &&
e[3] != postfix.Lexeme &&
e[4] != printer.Print(expression)) {
Console.WriteLine("Error parsing: " + e[0]);
}
}
}
private static void ExecuteREPL()
{
string infix = "";
Console.WriteLine("Enter a syntactically valid mathematical expression, such as (2 + 3) * 4.");
Console.WriteLine("Only integer math, parenthesis, and operators +, -, *, /, ^ supported.");
while (true) {
Console.Write("> ");
infix = Console.ReadLine();
int value = new InfixEvaluatorParser(new ExpressionLexer()).Parse(infix);
Token prefix = new InfixToPrefixParser(new ExpressionLexer()).Parse(infix);
Token postfix = new InfixToPostfixParser(new ExpressionLexer()).Parse(infix);
Expression expression = new InfixToAbstractSyntaxTreeParser(new ExpressionLexer()).Parse(infix);
FlatExpressionPrinter flatPrinter = new FlatExpressionPrinter();
HierarchicalExpressionPrinter HierarchicalPrinter = new HierarchicalExpressionPrinter();
Console.WriteLine("Value: " + value);
Console.WriteLine("Prefix notation: " + prefix.Lexeme);
Console.WriteLine("Postfix notation: " + postfix.Lexeme);
Console.WriteLine("Flat syntax tree: " + flatPrinter.Print(expression));
Console.WriteLine("Hierarchical syntax tree: " + Environment.NewLine);
Console.WriteLine(HierarchicalPrinter.Print(expression));
}
}