30 lines
873 B
Racket
30 lines
873 B
Racket
#lang racket
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(provide explicate-control)
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(require racket/fixnum)
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(require "lvar.rkt")
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(require "cvar.rkt")
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(define (explicate-control program)
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(match program
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[(Program info body)
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(CProgram info (list `(start . ,(explicate-control-tail body))))]))
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; after a remove-complex-opera*, all expressions
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; are in monadic normal form
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(define (explicate-control-tail exp)
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(match exp
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[(Int _) (Return exp)]
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[(Var _) (Return exp)]
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[(Prim _ _) (Return exp)]
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[(Let varname rexp body)
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(explicate-control-assign varname rexp (explicate-control-tail body))]))
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; stmt := (assign var exp)
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; tail := (return exp) / (seq stmt tail)
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(define (explicate-control-assign varname exp cvar-body)
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(match exp
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[(Let v x b) (explicate-control-assign v x (explicate-control-assign varname b cvar-body))]
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[_ (Seq (Assign (Var varname) exp) cvar-body)]))
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