视频与PR：https://github.com/terrajobst/minsk/blob/master/docs/episode-01.md
作者是 Immo Landwerth（https://twitter.com/terrajobst），微软 .NET 团队的项目经理。
这一集主要内容是一个原始的递归下降 Parser。
思路：
1.Lexer
(1) enum SyntaxKind
(2) abstract class SyntaxNode
(3) class SyntaxToken : SyntaxNode
(4) class Lexer
2.Expression
(1) abstract class ExpressionSyntax : SyntaxNode
(2) sealed class NumberExpressionSyntax : ExpressionSyntax
(3) sealed class BinaryEpressionSyntax : ExpressionSyntax
(4) sealed class ParenthesizedExpressionSyntax : ExpressionSyntax
3.Parser
(1) sealed class SyntaxTree
(2) class Parser
处理优先级的技巧：
public ExpressionSyntax ParseTerm()
{
var left = ParseFactor();
while (Current.Kind == SyntaxKind.PlusToken || Current.Kind == SyntaxKind.MinusToekn)
{
var operatorToken = NextToken();
var right = ParseFactor();
left = new BinaryEpressionSyntax(left, operatorToken, right);
}
return left;
}
public ExpressionSyntax ParseFactor()
{
var left = ParsePrimaryExpression();
while (Current.Kind == SyntaxKind.StarToken || Current.Kind == SyntaxKind.SlashToken)
{
var operatorToken = NextToken();
var right = ParsePrimaryExpression();
left = new BinaryEpressionSyntax(left, operatorToken, right);
}
return left;
}
4.Evaluator
(1) class Evaluator
5. 其他
比如诊断信息等
C#语言点：
1.public override IEnumerable<SyntaxNode> GetChildren() => Enumerable.Empty<SyntaxNode>();
2.yield
原文：https://www.cnblogs.com/wqyu/p/10807005.html