mirror of https://github.com/docker/buildx.git
29 lines
871 B
Markdown
29 lines
871 B
Markdown
# HCL User Functions Extension
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This HCL extension allows a calling application to support user-defined
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functions.
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Functions are defined via a specific block type, like this:
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```hcl
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function "add" {
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params = [a, b]
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result = a + b
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}
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function "list" {
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params = []
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variadic_param = items
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result = items
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}
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```
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The extension is implemented as a pre-processor for `cty.Body` objects. Given
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a body that may contain functions, the `DecodeUserFunctions` function searches
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for blocks that define functions and returns a functions map suitable for
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inclusion in a `hcl.EvalContext`. It also returns a new `cty.Body` that
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contains the remainder of the content from the given body, allowing for
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further processing of remaining content.
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For more information, see [the godoc reference](https://pkg.go.dev/github.com/hashicorp/hcl/v2/ext/userfunc?tab=doc).
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