Translators

Question 1

What is a translator?

Answer 1

A translator changes a program written in one language into another language (usually machine code)

Question 2

What is an assembler?

Answer 2

An assembler converts low level assembly language into machine code.

Question 3

What is an Interpreter?

Answer 3

An interpreter converts high-level language one line at a time into machine code and executes it.

Question 4

What is a Compiler?

Answer 4

A compiler converts high-level language into machine code for execution at a later time. The entire program is converted at once.

Question 5

Differences between an interpreter and a compiler?

Answer 5

Execution Speed -
- An interpreter is slower than a compiler because the code must be reinterpreted each time the program is run
- Compliers can produce much more efficient code than interpreters making the compiled programs runs faster.

Complexity -
- Interpreters are smaller, simpler programs
- Compliers tend to be large complex programs

Error Reporting -
- In error reporting, the interpreter would encounter the errors and report it to the user immediately and stops the program from running.
- The compiler would analyse the entire program, taking note of where errors have occurred and record them in an error file.

Question 6

What is Lexical Analysis?

Answer 6

• Spaces and comments are removed from the code
• Identifiers, keywords and operators are replaced by tokens. A token is similar to a variable with a name and a value.
• A symbol table is created. This table stores the addresses of all variables, labels and subroutines used in the program

Question 7

What is Syntax Analysis?

Answer 7

• The tokens created in the first stage are checked to see if they follow the syntax rules of the programming language (parsing).
• During parsing, if a syntax error is found then an error message is displayed and compilation stops.

Question 8

Semantic Analysis

Answer 8

• Variable checks ensure they are correctly declared and use a valid data type.
• Operation checks ensure they are correct for the data type.

Question 9

Code Generation

Answer 9

The machine code is generated.

Question 10

Code optimisation

Answer 10

The code is optimised so it is fast, efficient and uses a little of the computer’s resources as possible