39 lines
1.2 KiB
Markdown
39 lines
1.2 KiB
Markdown
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# Reflection Functions
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Sprig provides rudimentary reflection tools. These help advanced template
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developers understand the underlying Go type information for a particular value.
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Go has several primitive _kinds_, like `string`, `slice`, `int64`, and `bool`.
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Go has an open _type_ system that allows developers to create their own types.
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Sprig provides a set of functions for each.
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## Kind Functions
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There are two Kind functions: `kindOf` returns the kind of an object.
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```
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kindOf "hello"
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```
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The above would return `string`. For simple tests (like in `if` blocks), the
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`isKind` function will let you verify that a value is a particular kind:
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```
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kindIs "int" 123
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```
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The above will return `true`
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## Type Functions
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Types are slightly harder to work with, so there are three different functions:
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- `typeOf` returns the underlying type of a value: `typeOf $foo`
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- `typeIs` is like `kindIs`, but for types: `typeIs "*io.Buffer" $myVal`
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- `typeIsLike` works as `kindIs`, except that it also dereferences pointers.
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**Note:** None of these can test whether or not something implements a given
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interface, since doing so would require compiling the interface in ahead of time.
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