+The following site may be useful; it lets you run a Scheme interpreter inside your web browser: [Try Scheme in your web browser](http://tryscheme.sourceforge.net/). See also our links about [[learning Scheme]] and [[learning OCaml]].
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+1. Function application and parentheses
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+ In Scheme and the lambda calculus, the functions you're applying always go to the left. So you write `(foo 2)` and also `(+ 2 3)`.
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+ Mostly that's how OCaml is written too:
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+ foo 2
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+ But a few familiar binary operators can be written infix, so:
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+ 2 + 3
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+ You can also write them operator-leftmost, if you put them inside parentheses to help the parser understand you:
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+ ( + ) 2 3
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+ I'll mostly do this, for uniformity with Scheme and the lambda calculus.
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+ In OCaml and the lambda calculus, this:
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+ foo 2 3
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+ means the same as:
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+ ((foo 2) 3)
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+ These functions are "curried". `foo 2` returns a `2`-fooer, which waits for an argument like `3` and then foos `2` to it. `( + ) 2` returns a `2`-adder, which waits for an argument like `3` and then adds `2` to it. For further reading:
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+* [[!wikipedia Currying]]