21 lines
603 B
Plaintext
21 lines
603 B
Plaintext
!import "base" !Local
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!import "list" !Local
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!import "io" !Local
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-- Environment effects: ask and local.
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-- ask reads the current environment value.
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-- local f action runs action with the env transformed by f.
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--
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-- The CLI starts with an empty (Leaf) environment. This demo uses
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-- local to inject a real string so that ask returns something readable.
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main = io <|
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(bind
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local (_ : "sandbox")
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(bind ask (env :
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bind (putStrLn (append "working in env: " env)) (_ :
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pure "inside-done"))))
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(outside :
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bind (putStrLn (append "local returned: " outside)) (_ :
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pure t))
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