56 lines
1.7 KiB
Markdown
56 lines
1.7 KiB
Markdown
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# Garden
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An experiment in combining [Fennel](https://fennel-lang.org) and [Terra](https://terralang.org).
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## Rationale
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Idk, seemed cool
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## Usage
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At the top of your file, include the following:
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```fennel
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(import-macros {: def : q : ttype} :terra)
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```
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The `def` macro defines a new terra function. The `q` macro defines a quoted terra expression.
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The `ttype` macro allows you to specify terra type definitions that can't be expressed with
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regular lua syntax.
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Notably, all of these macros return values, and none of them define new variables, local or global.
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I could maybe be persuaded to make `def` work like `fn` and optionally define a local, but for now,
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eh, whatever.
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### def
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Defines a function, compiling down to the `terra` keyword.
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Syntax:
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```fennel
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(def [argname1 argtype1 argname2 argtype2... : rettype1 rettype2...] statement...)
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```
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Simple example:
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```fennel
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(local add (def [x int y int : int]
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(return (+ x y))))
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(add 1 2) ; returns 3
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```
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To define a function as returning "void", simply end the argument list with a `:`.
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To make terra infer the return type, do not include a `:` in the argument list at all.
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Unlike Fennel, we do not implement implicit return semantics, and early returns are A-OK.
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Sorry Phil.
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### q
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Defines a terra quotation, compiling down to the `\`` operator if given one argument, and
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`quote` / `end` if given more than one.
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### syntax within `def` and `q` forms
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```fennel
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(var name initial-value)
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(var name type initial-value)
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```
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Define a local variable named `var`, and set its initial value to `initial-value`. You can
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manually specify a `type`, or you can let terra infer it from `initial-value`. There is no
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syntax for _not_ initalizing the variable on declaration.
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```fennel
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```
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