CF Pascal, , . , , , . , , , .., . , , , .
, . ? ? ? (, , , ) ? . , , .
- (BNF) CF Pascal. , BNF CF Pascal.
, , . , , , -. , , . : ,
, , . : . : , . . , .
CF Pascal , , (INPUT) (OUTPUT). , : INPUT OUTPUT -.
CF PASCAL.
5 . , , , .
. X Y , . X,Y , .
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- X0 , X0 .
.
PROGRAM Copy (INPUT, OUTPUT);
{Writes first character in INPUT to OUTPUT}
VAR
Ch: CHAR;
BEGIN
READ(Ch);
WRITELN(Ch);
END.
, ( ) . , .
. . , , , . , , , .
.
,, , .
: , , , , , , , .
( ) - , .
, , 0-, . :
- 0-
□ - 1-
string - 6-
□string□ - 8-
, S □.
, . 1- , , . , □ , □ - 1-.
, : S = string. , . - , , .
CF Pascal :
CF Pascal | |
WRITE(ABC) | |
WRITE(Ch) | |
READ(Ch) |
.
.
, WRITE. WRITE, < > < >, OUTPUT.
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CF Pascal WRITE OUTPUT. , . :
C= character
S= string
C&S=characterstring
S&C=stringcharacter
S&S=stringstring
:
& S = S & = S
( , - ), ( ), ((C&B)&S = C&(B&S)) (S&C ¹ C & S).
.
W = WRITE(Any, string) S = string , W. , S W.
P Q, X Y,
Q= X & P & Y
S W
W = WRITE(Any, & S & )
X = WRITE(Any,
Y = )
T = tring
S = s & T
T- S
X = s
Y =
S = s & T &
, . , .
.
WRITE , CHAR , OUTPUT. , Ñ. .
strin Ñ g = string
Ñ g = g
, 1- .
, :
Ñ g = g
( , - ), , .
a Ñ b | |
Ñ x | 1-, |
N Ñ |
.
WRITE , READ . READ INPUT . INPUT , READ, .
(head) (tail) , READ. (Θ) (Λ) , .
Θ S S
Λ S S
:
S = string
T = tring
Θ S = s
Λ S = tring = T
Θ T = t
Λ T = ring
, , :
Θ (Λ T) = r
Λ(Λ T) = ing
Λ (Λ(Λ T)) = ng
Θ (Λ (Λ(Λ T))) = n
- -1 , .
:
- , .
, , .
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Θ string = s
Λ string = tring
Ñ(Θ string) = s
(Ñ(Θ string)) & (Λ string) = s & tring = string
, , , : S :
(Ñ(Θ S)) & (Λ S) = S
.
& | me & you = meyou | |
Ñ | pluralÑs = plurals | |
1- | Ñ | Ñv = v |
Θ | Θfeet = f | |
Λ | Λrattle = attle |
.
. , - , , . , , . .
, , . , .
,
this is a list example
<th, is , is , a , list example>
. Pascal OUTPUT, , .
WRITE(this is a list example);
WRITE(th, is , is , a , list example);
, , , :
L = <th, is , is , a , list example>
M = <this is a list example>
, , , . . , BNF.
x K,
x Î K, K x, , x Ï K.
, is Î L, is Ï M.
L , :
L1 = th
L2 = is
L3 = is
L4 = a
L5 = list example
M
M1 = this is a list example
, 1 .. L 5-, M - 1-. , 0-, <>. , , . , M 1- M1
M = <M1>, M ¹ M1
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,
<> ¹ <>
<> 1-, , <> - 0- .
, . ,
C = <c, h, a, r, a, c, t, e, r>
, character
<M, M> = <<this is a list example>, <this is a list example>>
2- 1- , .
,
Q = <A, <A>, A>
, , .
Q2 A.
(Q2)1 = A
.
, , : , , .
& , . L & M L, M, L.
Ñ . L Ñ x, L, x, L.
Θ , . Λ , . .
. L M, X Y,
M = X & L & Y
.
& | <A> & <A, B> = <A, A, B> <12, <A>> & <X> = <12, <A>, X> | |
Ñ | <A> Ñ B = <A, B> <A> Ñ <> = <A, <>> <A> Ñ = <A, > <> Ñ V = <V> <> Ñ <> = <<>> | |
Θ | Θ<X, <X>> = X | |
Λ | Λ<X, <X>> = <<X>> |
, . , . , k m Q
Θ Q, Θ(Λ Q), Θ(Λ (Λ Q)),
, k m.