25 lines
733 B
Markdown
25 lines
733 B
Markdown
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# ppx_get_env
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This folder contains an example of a very simple ppx rewriter that will expand
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`[%get_env "SOME_ENV_VAR"]` into the value of the env variable `SOME_ENV_VAR` at compile time,
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as a string.
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E.g., assuming we set `MY_VAR="foo"`, it will turn:
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```ocaml
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let () = print_string [%get_env "MY_VAR"]
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```
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into:
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```ocaml
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let () = print_string "foo"
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```
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Note that this is just a toy example and we'd actually advise you against this type of ppx
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that have side effects or rely heavily on the file system or env variables unless you absolutely know
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what you are doing.
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In particular in this case it won't work well with dune since dune won't know about the dependency
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on the env variables specified in the extension's payload.
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