3.6.3.1 Types of Program Translator.

Question 1

Define what is meant by a translator.

Answer 1

Translates programs written in high-level languages or assembly code into machine code for execution.

Question 2

Outline the types of program translators.

Answer 2

Assemblers.
Compilers.
Interpreters.

Question 3

Define an assembler.

Answer 3

Translates an assembly language into machine code.

Question 4

Why are assemblers quick and straight forward?

Answer 4

Because each assembly

language instruction has a 1-to-1 relationship to a machine code instruction.

Question 5

What is meant by platform specific assemblers?

Answer 5

A different assembler must exist for each

different type of processor instruction set.

Question 6

Define a compiler.

Answer 6

Translates high-level languages into machine code, all at once.

Question 7

Outline the process of a compiler.

Answer 7

Compilers take a high-level program as their source code,

check it for any errors and then translate the entire program at once.

Question 8

What happens to the compiler if there is an error in the code?

Answer 8

It will not translate (compile).

Question 9

Outline what happens once code has been translated (compiler).

Answer 9

Once translated, a compiled program can be run without the requirement for any other software to be present

Question 10

Why are compilers platform specific?

Answer 10

Because they produce machine code.

Question 11

Define an interpreter.

Answer 11

Translates high-level languages into machine code, line-by-line.

Question 12

What allows an interpreter to translate each kind of program instruction?

Answer 12

Interpreters have procedures that can be used to translate each kind of program instruction.

Question 13

How do interpreters check for errors?

Answer 13

As they go, meaning that a program can be partially translated by an interpreter until the error is reached.

Question 14

Why is code translated by an interpreter said to be poorly protected?

Answer 14

As when a program is translated, both the program source code and the interpreter must be present. This results in poor protection of the source code
compared to compilers which make the original code difficult to extract.

Question 15

Compare the error checking of compilers and interpreters.

Answer 15

Compilers check source code errors line-by-line before translating whereas interpreters begin translation immediately.

Question 16

Compare the translation of compilers and interpreters.

Answer 16

Compilers translate entire source code at once whereas interpreters check each line for errors and then translate sequentially.

Question 17

Compare the presence of other software during the execution of both compiler and interpreter.

Answer 17

Compilers have no need for source code or compiler to be present when translated code is executed whereas interpreters must have both source code and interpreter present.

Question 18

Compare the protection of code with both interpreter and compiler.

Answer 18

Compilers protect the source code from extraction whereas interpreters offer little protection.

Question 19

Define what is meant by an intermediate language.

Answer 19

Some compilers don’t produce machine code straight away but instead translate source
code into an intermediate language. Often bytecode.

Question 20

What do intermediate languages allow for?

Answer 20

Platform independence.

The interpreter to translate the source code just
once, while still being able to execute the translated code with a variety of different processors.

Question 21

Outline the process of compilers and interpreters.

Answer 21

A compiler that uses an intermediate language will translate high-level code into an intermediate language such as bytecode and then use a virtual machine to execute the
bytecode on different processors.

Each different processor instruction set will have its own
virtual machine.

Question 22

Define source code.

Answer 22

Source code is the name given to the input to a translator.

Question 23

What would the source code be for an assembler?

Answer 23

An assembly language.

Question 24

What would the source code be for a compiler or interpreter?

Answer 24

A high-level programming language.

Question 25

Define object code.

Answer 25

A translator’s output is called object code and is produced from source code.

Question 26

Where is the object code produced from?

Answer 26

The source code.