You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
|
|
|
|
|
#lang br
|
|
|
|
|
|
(require "go.rkt")
|
|
|
|
|
|
(provide b-if b-comp-expr b-logic-expr)
|
|
|
|
|
|
|
|
|
|
|
|
;; b-if : /"if" b-expr /"then" b-expr [/"else" b-expr]
|
|
|
|
|
|
(define (b-if cond-expr then-expr [else-expr #f])
|
|
|
|
|
|
(cond
|
|
|
|
|
|
[(not (zero? cond-expr)) (b-goto then-expr)]
|
|
|
|
|
|
[else-expr => b-goto]))
|
|
|
|
|
|
|
|
|
|
|
|
(define bool-int (λ (val) (if val 1 0)))
|
|
|
|
|
|
(define bi= (compose1 bool-int =))
|
|
|
|
|
|
(define bi< (compose1 bool-int <))
|
|
|
|
|
|
(define bi> (compose1 bool-int >))
|
|
|
|
|
|
|
|
|
|
|
|
;; b-comp-expr : b-cond-expr [("and" | "or") b-cond-expr]
|
|
|
|
|
|
(define-macro-cases b-logic-expr
|
|
|
|
|
|
[(_ ARG) #'ARG]
|
|
|
|
|
|
[(_ LEFT "and" RIGHT) #'(and LEFT RIGHT)]
|
|
|
|
|
|
[(_ LEFT "or" RIGHT) #'(or LEFT RIGHT)])
|
|
|
|
|
|
|
|
|
|
|
|
;; b-cond-expr : b-expr [("=" | "<" | ">") b-expr]
|
|
|
|
|
|
(define-macro-cases b-comp-expr
|
|
|
|
|
|
[(_ ARG) #'ARG]
|
|
|
|
|
|
[(_ LEFT "=" RIGHT) #'(bi= LEFT RIGHT)]
|
|
|
|
|
|
[(_ LEFT "<" RIGHT) #'(bi< LEFT RIGHT)]
|
|
|
|
|
|
[(_ LEFT ">" RIGHT) #'(bi> LEFT RIGHT)])
|
