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Use the new REPL functions in the tutorial

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oakes
2014-08-10 23:04:10 -04:00
parent 8965588d98
commit 12bfdd6a94
1 changed files with 3 additions and 3 deletions
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TUTORIAL.md
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@@ -376,13 +376,13 @@ First, switch the REPL into the right namespace by typing `(in-ns 'hello-world.c
`(on-gl (set-screen! hello-world main-screen))`
The next thing to try is reading and modifying state. Let's peek into the entities vector by typing the following into the REPL:
The next thing to try is reading and modifying state. We'll be using some REPL-specific functions, so type `(use 'play-clj.repl)` to bring them in. Let's peek into the entities vector by typing the following into the REPL:
`(-> main-screen :entities deref)`
`(e main-screen)`
That should print out a vector with a single map inside of it. Now try moving your image and then run the command again. The `:x` and `:y` values should now be updated. You're looking at your game in real-time! Lastly, let's try moving the entity from the REPL:
`(-> main-screen :entities (swap! #(vector (assoc (first %) :x 200 :y 200))))`
`(e! identity main-screen :x 200 :y 200)`
Lastly, one common issue people have with play-clj in a REPL is that it if you make an error that causes an exception, it's difficult to restart the game after fixing it. To deal with this, there is the `set-screen-wrapper!` function, which lets you catch errors that occur in any screen function and handle them gracefully. For example, here we make it switch to a blank screen if any error occurs: