In the last lecture, we began looking at the programming This lecture nguage Scheme. with the intent of learning how that anguage would provide a basis for describing procedures and Adding procedures and procedural abstractions

luse this is the central part of the environment model, let's look in very painful detail at an example of an evaluation. In (square 4)I g particular, let's look at the evaluation of (square 4)with x;10 respect to the global environment. Here is the structure we start

The role of abstractions In this lecture, we are going to look at a very different style of creating large systems, a style called object oriented programming. This style focuses on breaking systems up in a different manner than those we have seen before To set the stage for this, we are first going to return to the notion of

Slide 14.1.1 Elements of ooP Last time we introduced the idea of object oriented systems Today, we want to build on those basics, looking at how we can expand object-oriented systems to deal with hierarchies of objects, to leverage the commonality of methods between

Slide 12.1.1 In the last lecture, we introduced mutation as a component of 6001s|cP our data structures We saw for example that set was a Environment mode way of changing the value associated with a variable in our system, and we saw that set-car! and set-cdr! were ways of changing the values of parts of list structure Now, several important things happened when we introduced

Chapter 2 Topics Syntax and Semantics Programs Composed of Several Functions s Syntax Templates Legal C++ Identifiers

One parse tree only a The role of the grammar a distinguish between syntactically legal and illegal programs a But that's not enough: it must also define a parse tree a the parse tree conveys the meaning of the program What if a string can be parsed with multiple parse trees? a we say the grammar is ambiguous a must fix the grammar(the problem is not in the parser) a Note: often a string can be derived in more than one way D ie, with more than one derivation sequence o this does not mean the grammar is ambiguous

Chapter 14 Objectives After you have read and studied this chapter, you should be able to Write programs that are easily extensible and modifiable by applying polymorphism in program design. Define reusable classes based on inheritance and abstract classes and abstract methods. Define methods using the protected modifier. Parse strings using a StringTokenizer object. 2000 McGraw-Hill

Chapter 8 Objectives After you have read and studied this chapter, you should be able to Declare and manipulate data of the char data type. Write string processing programs using String and StringBuffer objects. Differentiate the String and StringBuffer classes and use the correct class in solving given task. Distinguish the primitive and reference data types and show how the memory allocation between the two is different

Module 3: Operating-System Structure操作系统结构 1、System Components系统部件 2、Operating System Services操作系统服务 3、 System Calls系统调用 4、System Programs系统程序 5、 System Structure系统结构 6、Virtual Machines虚拟机 7、System Design and Implementation系统设计和实现 8、System Generation系统生成