<p>It's a functor map which is essentially an fmap function for the functor class. This might be of some use: <a href="https://www.fpcomplete.com/haskell/tutorial/operators/" rel="noreferrer">https://www.fpcomplete.com/haskell/tutorial/operators/</a></p>

CC BY-SA 4.0
2022-01-30T03:06:32.767Z
Hoogle is also a great resource for searching Haskell's syntax. https://hoogle.haskell.org/?hoogle=%3C%24%3E (edit: Oh I see your link immediately references Hoogle haha)
Travis
CC BY-SA 4.0
2022-01-30T02:36:36.620Z
2022-01-30T02:36:36.620Z
Samuel Leathers
<p>For Haskell questions of this sort <a href="https://hoogle.hackage.org/" rel="nofollow noreferrer">Hoogle</a> is the ultimate resource.</p>
<p>For operators like <code>&lt;$&gt;</code> you need to enclose them in parenthesis eg <code>(&lt;$&gt;)</code>.</p>

CC BY-SA 4.0
2022-01-30T21:20:27.810Z
2022-01-30T21:20:27.810Z
Erik de Castro Lopo
<p>I see the &lt;$&gt; notation often in the Plutus/Haskell code but have no idea what it means. I understand that $ alone is a parenthesis replacement. Is &lt;$&gt; similar? Does it suggest enclosing parenthesis?</p>
<p>Example from the deploy.hs script in week 3.</p>
<blockquote><pre>
dataToScriptData :: Data -> ScriptData
dataToScriptData (Constr n xs) = ScriptDataConstructor n $ dataToScriptData  xs
dataToScriptData (Map xs)      = ScriptDataMap [(dataToScriptData x, dataToScriptData y) | (x, y)  xs
dataToScriptData (I n)         = ScriptDataNumber n
dataToScriptData (B bs)        = ScriptDataBytes bs
<p></pre></blockquote></p>
<p>So hard to do a Google search on Haskell's cryptic syntax!</p>

<plutus-pioneer-program><haskell>
Meaning of <$> notation
# Meaning of <$> notation

(Asked by: username_0 on 2022-01-30)

I see the <$> notation often in the Plutus/Haskell code but have no idea what it means. I understand that $ alone is a parenthesis replacement. Is <$> similar? Does it suggest enclosing parenthesis?
Example from the deploy.hs script in week 3.

dataToScriptData :: Data -> ScriptData
dataToScriptData (Constr n xs) = ScriptDataConstructor n $ dataToScriptData  xs
dataToScriptData (Map xs)      = ScriptDataMap [(dataToScriptData x, dataToScriptData y) | (x, y)  xs
dataToScriptData (I n)         = ScriptDataNumber n
dataToScriptData (B bs)        = ScriptDataBytes bs

So hard to do a Google search on Haskell's cryptic syntax!

**Tags:** plutus-pioneer-program, haskell

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## 2 answers

### Answer by username_1 on 2022-01-30. Score: 5 | Accepted answer

It's a functor map which is essentially an fmap function for the functor class. This might be of some use: <https://www.fpcomplete.com/haskell/tutorial/operators/>

> **Comments:**
> **username_2**: Hoogle is also a great resource for searching Haskell's syntax. https://hoogle.haskell.org/?hoogle=%3C%24%3E (edit: Oh I see your link immediately references Hoogle haha)  

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### Answer by username_3 on 2022-01-30. Score: 3

For Haskell questions of this sort [Hoogle](https://hoogle.hackage.org/) is the ultimate resource.

For operators like `<$>` you need to enclose them in parenthesis eg `(<$>)`.


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