chapter4 Once Upon A Time

4-1 Hello 2

challenge: 1 line

code:4-1.a2b

(once)=(start)hello

4-2 Remove 2

challenge: 3 lines

code:4-2.a2b

(once)a=

(once)a=

(once)a=

4-3 Cut

challenge: 4 lines

code:4-3.a2b

xb=

xc=

xa=

(once)=(start)xxx

4-4 Remove 3

challenge: 5 lines

code:4-4.a2b

(once)=(end)@@@

a@=

b@=@b

c@=@c

@=

4-5 Reverse

challenge: 7 lines

code:4-5.a2b

(once)=(start)@

@a=(end)*a

@b=(end)*b

@c=(end)*c

a*=(start)a

b*=(start)b

c*=(start)c

4-6 Reverse 2

challenge: 6 lines

5 lines

code:4-6.a2b

(once)=(end)@@@@@@@

a@=(end)a

b@=(end)b

c@=(end)c

@=

4-7 Cut 2

challenge: 7 lines

code:4-7.a2b

(once)=(start)_@@

@a=(start)a

@b=(start)b

@c=(start)c

_a=(start)@@

_b=(start)@@

_c=(start)@@

4-8 Clone

challenge: 11 lines

code:4-8.a2b

(once)=(start)***

*a=(end)aa@

*b=(end)bb@

*c=(end)cc@

(once)=(end)|||

a|=|a

b|=|b

c|=|c

a@|=(start)a

b@|=(start)b

c@|=(start)c]

4-9 A to B 3

challenge: 5 lines

code:4-9.a2b

(once)=(start)_

_a=b_

_b=a_

_c=c_

(end)_=

4-10 Half

challenge: 8 lines

code:4-10.a2b

(once)=(start)-

--a=a-

--b=b-

--c=c-

-a=--

-b=--

-c=--

-=

4-11 Clone 2

challenge: 11 lines

code:4-11.a2b

(once)=(start)>

(once)=(end)<

a*=(start)a

b*=(start)b

c*=(start)c

a<=<aa*

b<=<bb*

c<=<cc*

<=

4-12 To B or not to B

challenge: 9 lines

7 lines

code:4-12.rb

(once)b=<b

<=(start)_

_a=b_

_b=b_

_c=c_

_=

a=c

4-13 Center

challenge: 10 lines

code:4-13.a2b

(once)=(start)>

(end)>a=a

(end)>b=b

(end)>c=c

a=(end)<

b=(end)<

c=(end)<

a<=(start)>

b<=(start)>

c<=(start)>

4-14 Center 2

challenge: 15 lines

14 lines

code:4-14.a2b

(once)=(end)_

a_=_@a

b_=_@b

c_=_@c

a@=@a

b@=@b

c@=@c

@@a=(end)a

@@b=(end)b

@@c=(end)c

_@a=(end)_

_@b=(end)_

_@c=(end)_

_=

4-15 Expansion

challenge: 13 lines

12 lines

code:4-15.a2b

(once)=[][[]]

[]a=a+[]

[]b=b+[]

[]c=c+[]

[]+=+[]

[]=

a+=aa

b+=bb

c+=cc

4-16 Merge

challenge: 9 lines

7 lines

code:4-16.a2b

(once)=(start).

.a=(end)a

.b=(end)b

(start)<,=

<=(start).

,a=<,.a

,b=<,.b