Attributes – Any property of a programming language construct such as The data type of a variable The value of an expression The location of a variable in memory

Symbol table: major inherited attribute and major data structure in a compiler Principal operations: – Insert: store the information provided by name declarations when processing these declarations – Lookup: retrieve the information associated to a name when that name is used in the associated code

A stack-based environment will result in a dangling reference when the procedure is exited if a local variable in a procedure can be returned to the caller The simplest example:

Why Compiler Writing machine language-numeric codes is time consuming and tedious

The idea of Recursive-Descent Parsing Viewing the grammar rule for a non-terminal A as a definition for a procedure to recognize an A The right-hand side of the grammar for A specifies the structure of the code for this procedure The Expression Grammar:

A bottom-up parser uses an explicit stack to perform a parse – The parsing stack contains tokens, nonterminals as well as some extra state information – The stack is empty at the beginning of a bottom-up parse, and will contain the start symbol at the end of a successful parse

8.1.1 Three-Address Code 8.1.2 Data Structures for theImplementation of Three-Address Code

由于国内英语教学中写作训练薄弱，大批学生只会单词，不懂语境和搭配，出现了各种可笑 的中文思维现象。我们写作教学中专门强调语感的培养，除单词记忆和句型操练之外，在此 专门选编了 300 个闪光的英文句子，涉及面很广，配有译文并用黑体标出了句子衔接的主 干框架。读者可以在阅读中仔细领会每句话表达的妙处，遣词造句的独特设计

重复译法是指翻译时重复原文中某些词，使译文表达明确具体。这是因为有些词在英语中是不必重复的，但在汉语中却必须重复，否则就会造成文理不通或逻辑混乱

翻译是把一种语言的信息用另一种语言表达出来，翻译的目的是使译文的读者能得到原作者所表达的思想，得到与原文读者大致相同的感受。翻译涉及到两种语言，而不同的语言名有不同的表达方式，所以翻译决不是从一种语言到一种语言的简单转换，它要求译者进行创造性的实践活动