lang quiz 2

Question 1

Alogl68

Answer 1

insane orthogonality

Question 2

Pascal

Answer 2

teaching language

Question 3

C

Answer 3

originally a sys language. Many operators poor type checking

Question 4

smalltalk

Answer 4

first OOP plus had built in gui

Question 5

C++

Answer 5

added OOP to C

Question 6

syntax

Answer 6

The form or structure oft he expressions, statements, and program units

Question 7

semantics

Answer 7

The meaning of the expressions, statements, and program units

Question 8

lexical analysis

Answer 8

converts characters in the source program into lexical units (tokens)

Question 9

token

Answer 9

syntactic family that forms a class of units (literal key word, operator)

Question 10

lexeme

Answer 10

the actual sequence of characters in the token, terminal

Question 11

meta lang

Answer 11

language used to describe other languages

Question 12

grammar

Answer 12

A meta-language used to define the syntax of a language

Question 13

recognizer

Answer 13

can verify if a sentence contains valid syntax for the language

Question 14

generator

Answer 14

generates a random syntactically valid sentence

Question 15

sentential form vs sentence

Answer 15

sentential form is any line in a derivation but a sentence is the final line with just terminals

Question 16

an ambiguous grammar has

Answer 16

multiple potential parse trees for the same sentence

Question 17

static type binding types

Answer 17

explicit (C++) Implied (fortran) inferencing (C++)

Question 18

dynamic type binding

Answer 18

Python and JS more expensive

Question 19

lifetime of a var

Answer 19

time it is bound to a particular memory cell

Question 20

static variables

Answer 20

exist at compile time. Never added to nor die. efficient, globally accessible, history sensitive subprogram support. Does not allow for recursion or sharing memory.

Question 21

stack dynamic

Answer 21

variables created when elaborated. allows recursion, conserves storage, however subprograms not history-sensitive, indirect addressing, increased allocate and deallocate over head

Question 22

explicit heap dynamic

Answer 22

programmer explicitly allocates and deallocates. allows for dynamic storage management, can be error prone and needs a complex management solution

Question 23

implicit heap dynamic

Answer 23

maximum flexibility but also inefficient because all attributes are re-assigned arrays and strings in JS

Question 24

scope

Answer 24

where is it visible and who is it visible to

Question 25

static (lexical )scoping

Answer 25

the normal scope. Human readable. disadvantage is we lose control as a variable is often visible in places we don’t want it to be or we have to massacre the code

Question 26

dynamic scoping

Answer 26

trace the subprogram calls. pretty much disappeared except for error handling