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-Hi. In this second video
of the redo of week 3,

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we are going to look at how to implement
the DieHandle we were talking about.

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Basically, we would like the handle API
to be "DieHandle new".

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"DieHandle new".

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We would like to add some die to it,
so "addDie:",

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for example, one with six faces.

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And another one with...

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ten faces, for example.

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"10" and "yourself".

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Cool.

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Basically, what this piece of code does

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is create an instance
of DieHandle class.

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This instance will receive
the message "addDie",

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so I would like to add a Die
to a handle

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with six faces, for example.

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This symbol right there will say

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that the next message will be sent
to the same receiver as the previous one.

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Basically, this message there
will be sent to the same receiver

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as this message there,

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that is the instance of DieHandle.

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We will send "addDie" twice
to the instance of a handle,

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once with a Die with six faces

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and another time
with a Die with ten faces.

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"Yourself" will output the instance.

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Let's write this.

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We will go to DieTest and...

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create "DieHandleTest".

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Save it.

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The first test method
we would like to make

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is "testCreationAndAdding".

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Basically, we will use that,

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but we will need a temporary variable,

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so "handle".

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And right there, "handle ="...

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I will tab everything. Dot.

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And then, we will test
the number of dices in the handle.

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So, "handle diceNumber", for example,

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"DiceNumber equals: 2".

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We have not defined anything

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but do not worry,
we will do it right away. Cmd+S.

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OK.

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And then, Define new class,
because we have not defined the handle.

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And we would like to add
the dice instance variable.

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This is a collection that will hold
all the dice we have added to the handle.

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OK.

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We have some red messages,
but that is fine.

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We will write another test,
"CreationWithTheSameDice".

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So, what we will do there is...

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I will write this on the same line,
remove that.

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We will add twice the same dice.

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So, dot.

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We will check
that the first time, it equals 1

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and the second time, it equals 2.

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We do not need to reinstantiate it.

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So, "handle addDie",

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we will add another die with six faces.

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This time, we would like
to have "diceNumber equals: 2".

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OK, cool.

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If we execute the test right away,

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we can see that the Debugger opens

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and nothing is implemented,
so that is normal.

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We will go over to the Class
and go to Inst. side method.

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First, we will write
an "initialize" method.

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So, "initialize",

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call "super initialize".

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And then,
give to the dice instance variable

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the value of a new "OrderedCollection".

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Now, we need to add a die.
So, "addDie: aDie".

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What we will do is simply call "add"
on the dice collection,

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so "add: aDie".

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Save this.

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We will need a getter of our dice
and instance variables,

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so "dice".

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Save this.

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And finally, "diceNumber".

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"DiceNumber" that will return
for size of the dice collection.

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Save.

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We have got our four methods.

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If we run our tests again,
they are now green.

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It is a great time to save,
so go to Tools,

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Iceberg,

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then we can go over to there.

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"Uncommitted changes".

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I will just repair this.

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"Checkout branch

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discarding image changes".

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OK.

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So, we will add everything.
OK, Checkout.

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OK, Commit.

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So, normally you should just have
to commit everything.

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This is because I am messing around
with my branches, but it should be fine.

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Now, it is up-to-date.

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And we can go over to there

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and look at the output
"Die withFaces" gives us.

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If I press Cmd+P or print,
I can right-click and go to Print it.

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We can go to "aDie"

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and if we go to this one,
it will output "aDie" as well.

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While it is kind of useful,

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we can make it better by, for example,
displaying the number of faces.

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In order to do so,

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we will go to the die Class

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and we will write a method
called "printOn".

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"PrintOn: aStream".

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This is a method that is already defined
but we will extend it,

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so "super printOn: aStream"

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because we would like to keep
the "aDie" thing for now, so "aDie".

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We would like to add
the number of faces,

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so "aStream nextPutAll:".

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We will add an open parenthesis.

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Then, in order to concatenate strings
in Pharo,

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you have to use the comma,
so comma, "faces printString".

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this will convert the number of faces
to a string, comma, closing parenthesis.

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Now, if I save this, go over to there
and press Cmd+P,

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we can see that we now have a number
of faces between parentheses,

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so "Die withFaces: 6", 
"Die withFaces: 10". That is great.

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What we need to do now

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is to make a "roll" method
for the DieHandle.

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Basically, how will we do this?

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We will do "roll",

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we need to keep the result
as a temporary variable,

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initialize it to 0,

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and then, we need to iterate
all the dice collection we have

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as an instance variable,

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so "dice"

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and what we will do
is call the method "do"

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and then, brackets
with double dash "each".

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This will iterate each member
of the dice collection

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and we will add the result of a roll

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so "res + each roll".

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"Do" will iterate
all the dice collection

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and for each of the dice
within the dice collection,

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we will roll it and add its results
to the global result "res".

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So, let's write "res". Save this.

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For testing purposes,
we will need a "maxValue".

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What is the "maxValue"?

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For example, for our handle there,
it would be 6 plus 10, so 16.

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This is exactly
what we will do right there.

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Instead of adding the roll,
we will add in the number of faces.

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Basically, this means this one rolls
the highest value possible, so 6,

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and this one as well, so 10.

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And this will return the "res".

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Save this.
Now, we will go over to the test.

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First, we will test

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the "testMaxValue".

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So, I will just borrow some of this.

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I will borrow everything. Let's go.

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So, I am there.

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"TestMaxValue", "handle",
we will create our handle,

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"self assert maxValue equals: 16".

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Save this test, run it.

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Everything is green, that is great.

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Now, the last one is "testRoll".

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And we will keep the same handle,

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but this time, we will do the same thing

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that we did for the "roll" method
for the die.

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We will do "10 timesRepeat"

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and then block with the assertion.

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Block, "self assert",

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but this will not be...

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We would like to verify

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that "handle roll is between"...

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I will put the parentheses first,
parenthesis there, parenthesis there,

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remove this.

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"Between"...

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If each die rolls 1,
basically, this would mean 1, 2,

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so the number of dice,

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"between handle diceNumber
and handle maxValue".

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That is why we needed
the "maxValue" function.

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That is great.

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Let's save it, run it,
you can see it is green,

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so everything is looking fine.

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We can save our repository once again,

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so Iceberg, "Uncommitted changes".

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This is what you are supposed to see
on the first time we save,

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so double-click on it.

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Now, Commit.

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And you can write, for example...

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What did we add?

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We added "maxValue", "roll",

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so "Roll method for DieHandle

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and better print for Die" and commit.

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Cool.

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This is the end of part 2.

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In part 3, we are going to look

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at how we can use the behavior we wanted
with, for example, "1 D4 + 2 D6",

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because right now, we have the back-end
simulation of what I have written there,

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but we have not...

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This message will not be understood
by the system for now.

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We will see that in the next part.