本文整理汇总了C#中Evaluator.Eval方法的典型用法代码示例。如果您正苦于以下问题：C# Evaluator.Eval方法的具体用法？C# Evaluator.Eval怎么用？C# Evaluator.Eval使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Evaluator的用法示例。
在下文中一共展示了Evaluator.Eval方法的4个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C#代码示例。
示例1: PrintTable
public static void PrintTable(string expression)
{
Evaluator<bool> eval = new Evaluator<bool>(expression, new ExpressionLib.Contexts.SimpleLogic());
foreach (string var in eval.Variables)
Console.Write("| " + var + " ");
Console.WriteLine("| " + expression);
Console.WriteLine();
Permutations(eval.Variables, (vals) => {
foreach ( bool v in vals.Values )
Console.Write("| " + SimpleLogic.ToString(v) + " ");
Console.WriteLine("| " + SimpleLogic.ToString(eval.Eval(vals)));
});
Console.WriteLine();
}示例2: TestCustomExterns
static void TestCustomExterns()
{
// Create an evaluator with custom defined functions:
var ev = new Evaluator()
{
{ "str", (v, e) => v.Eval(e[0]).ToString() },
{ "qualify", (v, e) =>
{
if (e.Count != 2) throw new ArgumentException("qualify requires 2 parameters");
// Evaluate parameters:
var prefix = v.EvalExpecting<string>(e[0]);
var list = v.EvalExpecting<object[]>(e[1]);
var sb = new StringBuilder();
for (int i = 0; i < list.Length; ++i)
{
if (list[i].GetType() != typeof(string)) throw new ArgumentException("list item {0} must evaluate to a string".F(i + 1));
sb.AppendFormat("[{0}].[{1}]", prefix, (string)list[i]);
if (i < list.Length - 1) sb.Append(", ");
}
return sb.ToString();
} },
{ "prefix", (v, e) =>
{
if (e.Count != 2) throw new ArgumentException("prefix requires 2 parameters");
// Evaluate parameters:
var prefix = v.EvalExpecting<string>(e[0]);
var list = v.EvalExpecting<object[]>(e[1]);
var sb = new StringBuilder();
for (int i = 0; i < list.Length; ++i)
{
if (list[i].GetType() != typeof(string)) throw new ArgumentException("list item {0} must evaluate to a string".F(i + 1));
sb.AppendFormat("[{0}].[{1}] AS [{0}_{1}]", prefix, (string)list[i]);
if (i < list.Length - 1) sb.Append(", ");
}
return sb.ToString();
} }
};
// Run through some test cases:
{
const string code = @"{prefix st [StudentID FirstName LastName]}";
var prs = new Parser(new Lexer(new StringReader(code)));
var expr = prs.ParseExpr();
// Evaluate and output:
var result = ev.Eval(expr);
Output(result);
Console.WriteLine();
}
}示例3: Main
static void Main(string[] args)
{
// With apologies to Philip Greenspun.
string[] badCodes = new string[]
{
// All should error:
@"",
@"(",
@")",
@"[",
@"]",
@"'",
@"'\'",
@"'\b'",
@"(true)",
@"(null)",
@"(())",
@"([] ())",
@"~",
@"-",
@"(.ToString null)",
};
string[] goodCodes = new string[]
{
// All should succeed:
@"true",
@"false",
@"null",
@"'test'",
@"~(if true true false)",
@"(eval ~(if true true false))",
@"(if true 'hello' 'world')",
@"(if false 'hello' 'world')",
@"(if (eq true false) true false)",
@"(if (eq false false) true false)",
@"(if (eq false false) true null)",
@"(if (eq null null) true null)",
@"(if (ne true false) true false)",
@"(if (ne false false) true false)",
@"(if (ne false false) true false)",
@"(if (ne null null) true false)",
@"'hello
world'",
@"'hello\nworld'",
@"'hello\t\rworld'",
@"'hello \'world\''",
@"'hello ""world""'",
@"`multiline
raw
string literal with ""quotes"" inside
it and 'quotes' too.
<html> is possible here.`",
@"~'test'",
@"~1.34",
@"~1.34d",
@"~1.34f",
@"1.333333333333333333333333333333333333",
@"1.333333333333333333333333333333333333d",
@"1.333333333333333333333333333333333333f",
@"1",
@"008",
@"-1",
@"[10 -3]",
// NOTE(jsd): Currently, whitespace separators are ignored for parsing purposes. This is subject to change.
@"(.ToString (System.DateTime/Now) 'yyyyMMdd')",
@"(. ToString (System . DateTime/Now) 'yyyyMMdd')",
@"(.ToString (System. DateTime / Now) 'yyyyMMdd')",
// TODO: add, inc, dec functions and possibly other basics:
//@"(add x y)",
//@"(inc 1)",
//@"(dec 1)",
// TODO: let with scoping
//@"(let [x 1, y 2] (add x y))",
};
{
int pass = 0, fail = 0;
// Test the bad codes which should always fail:
for (int i = 0; i < badCodes.Length; ++i)
{
string code = badCodes[i];
try
{
var prs = new Parser(new Lexer(new StringReader(code)));
var expr = prs.ParseExpr();
// Evaluate:
var ev = new Evaluator();
var result = ev.Eval(expr);
// Failed! Should've gotten some sort of exception.
++fail;
}
//.........这里部分代码省略.........
示例4: Main
static void Main(string[] args)
{
//string expr = "pr/2+(-3*2)^2 * sqrt(2+2) * max(sqrt(2), sqrt(4))";
string expr = "(1 + 2.5) * 3";
Dictionary<string, double> vars = new Dictionary<string, double>();
vars.Add("pr", -1);
Evaluator<double> eval = new Evaluator<double>(expr, new SimpleMath());
try
{
Console.WriteLine("Sample math expression: " + expr);
Console.WriteLine("In postfix format: " + eval.Expression);
Console.WriteLine("Result: " + eval.Eval(vars));
}
catch (ParsingException e)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine(e.Message);
Console.ForegroundColor = ConsoleColor.Gray;
}
Console.WriteLine("----------------------------------------");
Evaluator<bool> evalLogic = new Evaluator<bool>(new SimpleLogic());
string exprLogic = "(F | (!T > T)) = ((F & T) > (F > T))";
try
{
Console.WriteLine("Sample logical expression: " + exprLogic);
Console.WriteLine("Result: " + evalLogic.EvalInfix(exprLogic));
}
catch (ParsingException e)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine(e.Message);
Console.ForegroundColor = ConsoleColor.Gray;
}
Console.WriteLine("----------------------------------------");
//string exprLogic2 = "(p > (q > r)) > ((s > t) > (u > v))";
//string exprLogic2 = "(p -> (not q -> r)) <-> ((r -> !q) -> (p -> r))";
string exprLogic2 = "(((a|b)>(c=d))&(f^g))=h";
try
{
Console.WriteLine("Truth table of: " + exprLogic2);
Console.WriteLine();
TruthTables.PrintTable(exprLogic2);
}
catch (ParsingException e)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine(e.Message);
Console.ForegroundColor = ConsoleColor.Gray;
}
Console.WriteLine("\nPress any key to continue...");
Console.ReadKey();
}