Merge pull request #247 from carlrobert/patch-17

Known times() limitation mentioned
This commit is contained in:
Walter Higgins 2015-06-07 14:09:30 +01:00
commit 1ee38d809e

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@ -478,7 +478,7 @@ Drone.extend = function( name, func ) {
/**************************************************************************
### Drone.times() Method
The times() method makes building multiple copies of buildings
The `times()` method makes building multiple copies of buildings
easy. It's possible to create rows or grids of buildings without
resorting to `for` or `while` loops.
@ -486,53 +486,57 @@ resorting to `for` or `while` loops.
* numTimes : The number of times you want to repeat the preceding statements.
#### Limitation
For now, don't use `times()` inside a Drone method implementation – only use it at the in-game prompt as a short-hand workaround for loops.
#### Example
Say you want to do the same thing over and over. You have a couple of options...
Say you want to do the same thing over and over. You have a couple of options:
* You can use a for loop...
* You can use a `for` loop …
d = new Drone(); for ( var i = 0; i < 4; i++ ) { d.cottage().right(8); }
While this will fit on the in-game prompt, it's awkward. You need to
declare a new Drone object first, then write a for loop to create the
4 cottages. It's also error prone, even the `for` loop is too much
declare a new Drone object first, then write a `for` loop to create the
4 cottages. It's also error prone &ndash; even the `for` loop is too much
syntax for what should really be simple.
* You can use a while loop...
* You can use a `while` loop &hellip;
d = new Drone(); var i=4; while (i--) { d.cottage().right(8); }
... which is slightly shorter but still too much syntax. Each of the
&hellip; which is slightly shorter but still too much syntax. Each of the
above statements is fine for creating a 1-dimensional array of
structures. But what if you want to create a 2-dimensional or
3-dimensional array of structures? Enter the `times()` method.
The `times()` method lets you repeat commands in a chain any number of
times. So to create 4 cottages in a row you would use the following
statement...
statement:
cottage().right(8).times(4);
...which will build a cottage, then move right 8 blocks, then do it
&hellip; which will build a cottage, then move right 8 blocks, then do it
again 4 times over so that at the end you will have 4 cottages in a
row. What's more the `times()` method can be called more than once in
row. What's more, the `times()` method can be called more than once in
a chain. So if you wanted to create a *grid* of 20 houses ( 4 x 5 ),
you would do so using the following statement...
you would do so using the following statement:
cottage().right(8).times(4).fwd(8).left(32).times(5);
... breaking it down...
&hellip; breaking it down &hellip;
1. The first 3 calls in the chain ( `cottage()`, `right(8)`, `times(4)` ) build a single row of 4 cottages.
2. The last 3 calls in the chain ( `fwd(8)`, `left(32)`, `times(5)` ) move the drone forward 8 then left 32 blocks (4 x 8) to return to the original x coordinate, then everything in the chain is repeated again 5 times so that in the end, we have a grid of 20 cottages, 4 x 5. Normally this would require a nested loop but the `times()` method does away with the need for loops when repeating builds.
2. The last 3 calls in the chain ( `fwd(8)`, `left(32)`, `times(5)` ) move the drone forward 8 then left 32 blocks (4 x 8) to return to the original X coordinate, then everything in the chain is repeated again 5 times so that in the end, we have a grid of 20 cottages, 4 x 5. Normally this would require a nested loop but the `times()` method does away with the need for loops when repeating builds.
Another example: This statement creates a row of trees 2 by 3 ...
Another example: This statement creates a row of trees 2 by 3:
oak().right(10).times(2).left(20).fwd(10).times(3)
... You can see the results below.
&hellip; You can see the results below.
![times example 1](img/times-trees.png)