Assignment 8.

Author: dvanhorn

www/assignments.scrbl

@@ -11,7 +11,7 @@
 @include-section{assignments/6.scrbl}
 @include-section{assignments/7.scrbl}
 @include-section{assignments/8.scrbl}
-@include-section{assignments/9.scrbl}
+@;include-section{assignments/9.scrbl}
 @;include-section{assignments/10.scrbl}
 
 

www/assignments/8.scrbl

@@ -1,9 +1,123 @@
 #lang scribble/manual
 @(require "../defns.rkt")
-@title[#:tag "Assignment 8" #:style 'unnumbered]{Assignment 8: Functions with default arguments}
+@title[#:tag "Assignment 8" #:style 'unnumbered]{Assignment 8: Patterns}
+
+@(require (for-label (except-in racket ...)))
+@(require "../notes/ev.rkt"
+          "../notes/utils.rkt")
 
-@(require (for-label a86 (except-in racket ...)))
 
 @bold{Due: @assign-deadline[8]}
 
-Details of this assignment will be released later in the semester.
+The goal of this assignment is to extend a compiler with new pattern
+matching forms for matching lists, vectors, and predicates.
+
+You are given a file @tt{knock-plus.zip} on ELMS with a starter
+compiler similar to the @seclink["Knock"]{Knock} language we studied
+in class.  You are tasked with:
+
+@itemlist[
+
+@item{implementing the @tt{list} pattern,}
+
+@item{implementing the @tt{vector} pattern, and}
+
+@item{implementing the @tt{?} pattern.}
+]
+
+The following files have already been updated for you @bold{and should
+not be changed by you}:
+
+@itemlist[ @item{@tt{ast.rkt}}
+           @item{@tt{parse.rkt}}
+	   @item{@tt{interp.rkt}}
+           @item{@tt{interp-prim.rkt}}
+           @item{@tt{compile-op.rkt}}	   
+]
+
+So you will only need to modify:
+@itemlist[
+@item{@tt{compile.rkt}}
+]
+to correctly implement the new features. These features are described below.
+
+As a convenience, two new n-ary primitives have been added (and fully
+implemented): @racket[list] and @racket[vector].  The @racket[list]
+primitive takes any number of arguments and produces a list containing
+the arguments as elements; the @racket[vector] primitive does the
+same, but constructs a vector.
+
+@ex[
+(list)
+(list 1 2 3)
+(list 1 #t #\c)
+(vector)
+(vector 1 2 3)
+(vector 1 #t #\c)]
+
+These are not directly useful in implementing the patterns above, but
+do make it easier to write examples and tests.
+
+@section[#:tag-prefix "a5-" #:style 'unnumbered #:tag "list"]{List patterns}
+
+The @racket[(list _p1 ... _pn)] pattern matches a list of elements.  The
+pattern matches a list with as many elements as there are patterns
+@racket[_p1] through @racket[_pn] and each element must match the
+respective pattern.
+
+
+@ex[
+(match (list)
+  [(list) #t]
+  [_ #f])
+(match (list 1 2 3)
+  [(list x y z) x])
+(match (list (list 1) (list 2))
+  [(list (list x) (list 2)) x])
+]
+
+@section[#:tag-prefix "a5-" #:style 'unnumbered #:tag "vector"]{Vector patterns}
+
+The @racket[(vector _p1 ... _pn)] pattern matches a vector of elements.  The
+pattern matches a vector with as many elements as there are patterns
+@racket[_p1] through @racket[_pn] and each element must match the
+respective pattern.
+
+
+@ex[
+(match (vector)
+  [(vector) #t]
+  [_ #f])
+(match (vector 1 2 3)
+  [(vector x y z) x])
+(match (vector (vector 1) (vector 2))
+  [(vector (vector x) (vector 2)) x])
+]
+
+@section[#:tag-prefix "a5-" #:style 'unnumbered #:tag "vector"]{Predicate patterns}
+
+The @racket[(? _f)] pattern matches any value for which the predicate
+@racket[_f] returns a true value (any value other than @racket[#f])
+when applied to the value being matched.  In Knock+, @racket[_f] must be
+the name of a user defined function.
+
+@ex[
+(define (is-eight? x) (= x 8))
+(define (id x) x)
+
+(match 8
+  [(? is-eight?) #t]
+  [_ #f])
+(match (vector 1 2 3)
+  [(and (? id) x) x])
+(match 16
+  [(? is-eight?) #t]
+  [_ #f])
+]
+
+
+@section[#:tag-prefix "a5-" #:style 'unnumbered]{Submitting}
+
+Submit a zip file containing your work to Gradescope.  Use @tt{make
+submit.zip} from within the @tt{knock-plus} directory to create a zip
+file with the proper structure.

www/defns.rkt

@@ -61,8 +61,8 @@
               "Thursday, October 23, 11:59PM"
               "Tuesday, November 4, 11:59PM"
               "Tuesday, November 11, 11:59PM"
-              "Thursday, November 20, 11:59PM"
-              "Thursday, December 4, 11:59PM")
+              "Thursday, December 4, 11:59PM"
+              #;"Thursday, December 4, 11:59PM")
             (sub1 i)))
 
 (define office-hours