51 lines
1.5 KiB
Racket
51 lines
1.5 KiB
Racket
#lang typed/racket/base
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(provide (all-defined-out))
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;;;;;;;;;;;;;;
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;; Lexical environments
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;; A toplevel prefix contains a list of toplevel variables. Some of the
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;; names may be masked out by #f.
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(define-struct: Prefix ([names : (Listof (U Symbol False))])
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#:transparent)
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(define-struct: NamedBinding ([name : Symbol]
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[parameter? : Boolean]
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[boxed? : Boolean])
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#:transparent)
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(define-type CompileTimeEnvironmentEntry (U Prefix ;; a prefix
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NamedBinding
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False))
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;; A compile-time environment is a (listof (listof symbol)).
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;; A lexical address is either a 2-tuple (depth pos), or 'not-found.
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(define-type CompileTimeEnvironment (Listof CompileTimeEnvironmentEntry))
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;; A lexical address is a reference to an value in the environment stack.
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(define-type LexicalAddress (U EnvLexicalReference EnvPrefixReference))
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(define-struct: EnvLexicalReference ([depth : Natural]
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[unbox? : Boolean])
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#:transparent)
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(define-struct: EnvPrefixReference ([depth : Natural]
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[pos : Natural])
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#:transparent)
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(define-struct: EnvWholePrefixReference ([depth : Natural])
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#:transparent)
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;; An environment reference is either lexical or referring to a whole prefix.
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(define-type EnvReference (U EnvLexicalReference
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EnvWholePrefixReference)) |