25 lines
827 B
Racket
25 lines
827 B
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.
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(define-struct: Prefix ([names : (Listof Symbol)])
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#:transparent)
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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 (U Symbol
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Prefix)))
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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 LocalAddress PrefixAddress))
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(define-struct: LocalAddress ([depth : Natural])
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#:transparent)
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(define-struct: PrefixAddress ([depth : Natural]
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[pos : Natural]
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[name : Symbol])
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#:transparent) |