LR(0)，LL(0)，LALR(1)等之间的关系? [英] Relationship between LR(0), LL(0), LALR(1), etc?

问题描述

我真的很难理解之间的关系:

I'm really struggling to unterstand the relationship between:

• LR(0)
• LL(0)
• LALR(1)
• SLR(1)
• LR(1)
• LL(1)

我很确定LALR(1)和SLR(1)是LR(1)的子集，但是我对其他的内容一无所知.他们都是独家的吗? LL(0)是LL(1)的子集吗?

I'm pretty sure LALR(1) and SLR(1) are subsets of LR(1), but I'm lost about the others. Are they all exclusive? Is LL(0) a subset of LL(1)?

谢谢

推荐答案

包含规则如下:

• 每个LR(0)语法也都是SLR(1)，但并非所有SLR(1)语法都是LR(0).
• 每个SLR(1)语法也是LALR(1)，但并非所有LALR(1)语法都是SLR(1).
• 每个LALR(1)语法也都是LR(1)，但并非所有LR(1)语法都是LALR(1).
• 每个LL(1)语法也是LR(1)，但并非所有LR(1)语法都是LL(1).
• 每个LL(0)语法也是LR(0)，SLR(1)，LALR(1)，LR(1)和LL(1). (LL(0)语法基本上是无用的； 请参阅此问题以了解详细说明原因).

• Every LR(0) grammar is also SLR(1), but not all SLR(1) grammars are LR(0).
• Every SLR(1) grammar is also LALR(1), but not all LALR(1) grammars are SLR(1).
• Every LALR(1) grammar is also LR(1), but not all LR(1) grammars are LALR(1).
• Every LL(1) grammar is also LR(1), but not all LR(1) grammars are LL(1).
• Every LL(0) grammar is also LR(0), SLR(1), LALR(1), LR(1), and LL(1). (LL(0) grammars are basically useless; see this question for details why).

在同样情况下，每种语言都有LR(1)语法也有LR(0)语法，但前提是您要标记该语法，尽管不能保证该语法很漂亮.

It's also the case that every language that has an LR(1) grammar also has an LR(0) grammar provided that you endmark the grammar, though the grammar isn't guaranteed to be pretty.

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