Vocabulary

Question 1

Compile

Answer 1

To generate a dictionary in computer memory from source text (the written-out form of a definition).

Question 2

Dictionary

Answer 2

A list of words and definitions including both “system” definitions (predefined) and “user” definitions (which you invent). A dictionary resides in computer memory in compiled form.

Question 3

Execute

Answer 3

To perform the operations specified.

Question 4

Extensibility

Answer 4

A characteristic of a computer language that allows a programmer to add new features or modify existing ones.

Question 5

Glossary

Answer 5

A list of words defined in Forth, showing their stack effects and an explanation of what they do, which serves as a reference for programmers.

Question 6

Infix notation

Answer 6

The method of writing operators between the operands they affect.

Question 7

Postfix notation

Answer 7

The method of writing operators after the operands they affect. Also known as Reverse Polish Notation.

Question 8

Prefix notation

Answer 8

The method of writing operators before the operands they affect. Also known as Polish Notation.

Question 9

Actual arguments

Answer 9

The parameters/expressions used to call a function(or are passed to the function) .

Question 10

Formal parameters

Answer 10

The parameters which are used in the function prototype.

Question 11

Interpret

Answer 11

To read the input stream, then to find each word in the dictionary or, failing that, to convert it to a number.

Question 12

LIFO

Answer 12

Last in, first out.

Question 13

FIFO

Answer 13

First in, first out.

Question 14

Stack

Answer 14

A region of memory that is controlled in such a way that data can be stored or removed in a last-in, first-out (LIFO) fashion.

Question 15

Stack overflow

Answer 15

The error condition that occurs when the entire area of memory allowed for the stack is completely filled with data.

Question 16

Stack underflow

Answer 16

The error condition that occurs when an operation expects a value on the stack, but there is no valid data on the stack.

Question 17

Word

Answer 17

The name of a definition, a defined dictionary entry.

Question 18

Run-time

Answer 18

When a word is executed.

Question 19

Compile-time

Answer 19

When a definition is compiled.

Question 20

Organize procedures

Answer 20

1. Define useful tasks and give each task a name.

2. Group related tasks together into larger tasks and give each of these a name.

Question 21

Data stack

Answer 21

The region of memory which serves as common ground between various operations to pass arguments from one operation to another.

Question 22

Return stack

Answer 22

A region of memory distinct from the data stack which the Forth system uses to hold return addresses, among other things.

Question 23

Definite loop

Answer 23

A loop structure in which the words contained within the loop repeat a definite number of times.

Question 24

Infinite loop

Answer 24

loop structure in which the words contained within the loop continue to repeat without any chance of an external event stopping them, except for the shutting down or resetting the computer.

Question 25

Indefinite loop

Answer 25

A loop structure in which the words contained within the loop continue to repeat until some truth condition changes state.

Question 26

Cell

Answer 26

Fundamental data type of a Forth system.

Question 27

Factoring

Answer 27

Simplifying a large job by extracting those elements which might be reused and defining those elements as operations.

Question 28

Address interpreter

Answer 28

Interpreter that executes the list of addresses found in the dictionary entry of a colon definition.

Question 29

Body

Answer 29

The code and parameter fields of a Forth dictionary entry.

Question 30

Boot

Answer 30

To load the precompiled portion of Forth into the computer so that you can talk to the computer in Forth. This happens automatically when you turn the computer on or press "Reset".

Question 31

Cfa

Answer 31

Code field address. The address of a dictionary entry's code pointer field.

Question 32

Control task

Answer 32

On a multitasked system, a task which cannot converse with a terminal. Control tasks usually run hardware devices.

Question 33

Code pointer field

Answer 33

The cell in a dictionary entry that contains the address of the run-time code for that particular type of definition.

Question 34

Defining word

Answer 34

A Forth word that creates a dictionary entry.

Question 35

Electives

Answer 35

The set of Forth definitions that come with a system but not in the precompiled portion. The electives block loads the blocks that contain the electives definitions; the block can be modified as the user desires.

Question 36

Forward reference

Answer 36

In general, a reference to a waord that has not yet been defined.

Question 37

Head

Answer 37

The name and link fields of a Forth dictionary entry.

Question 38

Link field

Answer 38

The cell in a dictionary entry that contains the address of the previous definition, used in searching the dictionary.

Question 39

Name field

Answer 39

The area of a dictionary entry that contains the name of the defined word, along with the number of characters in the name.

Question 40

Pad

Answer 40

The region of memory within a terminal task that is used as a scratch pad to hold characters strings for intermediate processing.

Question 41

Parameter field

Answer 41

The area of a dictionary that contains the "contents" of the definition. Depending on its use, the length of a parameter field varies.

Question 42

Pfa

Answer 42

Parameter field address, the address of the first cell in a dictionary entry's parameter field.

Question 43

Precompiled portion

Answer 43

The part of the Forth system that is resident in object form immediately after the power-up or boot operation.

Question 44

Run-time code

Answer 44

A routine, compiled in memory, that specifies what happens when a member of a given class of words is executed.

Question 45

System variable

Answer 45

Variable provided by Forth, referred to system-wide (by any task).

Question 46

Task

Answer 46

A partition in memory that contains at minimum a data stack, a return stack, and a set of user variables.

Question 47

Terminal task

Answer 47

On a multitasked system, a task that can converse with a human being using a terminal; has a text interpreter, dictionary, and so on.

Question 48

Text input buffer

Answer 48

The region in memory within a terminal task that is used to store text as it arrives from a terminal. Incoming source text is interpreted here.

Question 49

User variable

Answer 49

Variable provided by Forth, whose value are unique for each task.

Question 50

Vectored execution

Answer 50

Method of specifying code to be executed by providing not the address of the code itself, but the address of a location which contains the address of the code. This location is often called vector.

Question 51

Vocabulary

Answer 51

An independently linked subset of the Forth dictionary.