Programming Languages Master Set - Test #1

Programmers use programming languages to instruct computers to do things.

The structure of programs (tokens

The expected behavior of a given syntactical construct.

Meaning of a language

• Describes the effects of executing the code

• Difficult to provide a comprehensive description of meaning in al contexts

a notation for communicating to a computer what we want it to do

proposed that computers should be permanently hardwired with a small et of general-purpose operations.

the first 4 bits of a line of code

indicates the type of operation to be performed

Next 12 bits contain code for the instructions operands.

a set of mnemonic symbols for instruction codes and memory locations

a program that translates the symbolic assembly language code to binary machine code

a program that loads the machine code into computer memory

FORmula TRANslation language

• developed by John Backus in the early 1950s

• Reflected the architecture of a particular type of machine

• lacked the structured control statements and data structures of later high-level language

ALGOrighmic Language released in 1960.

• Provided a standard notation for computer scientists to publish algorithms in journals.

• Included structured control statements for sequencing (begin-end blocks)

Translates programming language statements into machine code

ALGOL was the first language to receive a formal specification or definition

language for teaching programming in the 1970s

Descended form ALGOL

For embedded applications of U.S Dept of Defense

Computational model developed by mathematician Alonzo Church

Based on the theory of recursive functions.

Programming language that uses the functional model of computation

Data abstraction Control Abstraction

Simplify the behavior and attributes of data for humans

Ex: numbers, character strings, search trees, standard mathematical operations

simplify the behavior and attributes of data for humans

simplify properties of the transfer of control

Examples: loops

Collect the most localized machine information

Collect intermediate information about the structure of a program

Collect large-scale information in a program

Hides internal representation of common data values.

Values are also called "primitive' or "atomic" because the programmer cannot normally access the component parts or bits of the internal representation

Use of symbolic names to hide computer memory locations containing data values

names given to kinds of data values

The process of giving a variable a name and a data type

collects related data values into a single unit

Hides component parts but can be constructed from parts

a sequence of individually indexed items with the same data type

defining new data types (data and operations) that hide information

often associated with the concept of an abstract data type

a set of data values and the operations on those values

a set of operations available to the user

Internal representation of data values and operations

Reusability

components, library

gives information about the resource's components

statements that combine a few machine instructions into an abstract statement that is easier to understand

A mechanism that allows you to replace a complex notation with a simpler shorthand notation

Ex: x += 10 instead of x = x+10

Instructions that support selection and iteration to memory locations other than the next one

an object associated with a collection (such as array

groups a sequence of actions into a single action that can be called or invoked from other points in the program

names a procedure and associates it with the actions to be performed

the act of calling the procedure

values that can change from call to call

values supplied by the caller for the parameters

The system implementation of the program

• Stores information about the condition of the program and the way procedures operate

closely related to a procedure

• returns a value or result to its caller

• can be written to a correspond more closely to mathematical abstractions

a mechanism that further exploits the abstraction mechanism.

functions that can accept other functions as arguments and return functions as values

expects another function and a collection as arguments

applies the argument functions to each element in the argument collection and returns a list of results

a stand-alone collection of procedures providing logically related services to other parts of a program

Allows a program to be understood as a whole without needing to know the details of the services provided by the unit

other programs executing outside the Java system

mechanism in Ada for parallel execution

a language with three properties -Sequential execution of instructions -Use of variables representing memory locations -Use of assignment to change the values of variables

Pattern

requirement that a program be described as a sequence of instructions

Based on the abstract notion of a function in lambda calculus

Based on symbolic logic

Reusable code that operates in a way to mimic behaviors of real-world objects

similar to the grammar of a natural language

formal definition of the language's syntax

structure of the language's words

similar to spelling in natural languages

the language's words

includes keywords

No.

a program that accepts other programs and either directly executes them or transforms them into a form suitable for execution

Interpreter and Compiler

Executes a program directly

Produces an equivalent program in a form suitable for execution

Source program - input to the compiler

Target program - output from the compiler

• Translated by an assembler into an object program

• Linked with other object programs

• Loaded into appropriate memory locations

byte code

a form of low-level code

written differently for different hardware architectures

primary design criterion

• Early FORTRAN code more or less directly mapped to machine code

the quality of a language that enables a programmer to use it to express computation clearly

usually thought of as efficiency of the target code

how quickly and easily can a person read and write in the programming language?

how easy is it to express complex processes and structures?

refers to how well the features of a language are integrated

principle of least astonishment

• Generality

• Orthogonal design

• Uniformity

achieved by avoiding special cases in the availability or use of constructs and by combining closely related constructs into a single more general one

constructs can be combined in any meaningful way

a design in which similar things look similar and have similar meanings while different things look different

Can classify a feature or construct as irregular if it lacks one of these three qualities

Values are copied during assignment

Two references to the same object

is the program going to make the computer crash?

languages that prevent a programmer from compiling or executing any statements or expressions that violate the language definition

a language that allows the user to add features to it

specifies the syntax of a piece of code that expands to other standard code when compiled

a lot of people coding it

easy to move between cpus