takikawa

#lang racket

(require rackunit)

;; int -> string
(define (line n)
  (list->string (build-list n (λ (x) #\*))))

(check-equal? (line 3) "***")
(check-equal? (line 1) "*")

takikawa

. Type Checker: untyped identifier apply-contract imported from module <private/base.rkt> in: #%module-begin
. Type Checker: untyped identifier coerce-contract imported from module <private/guts.rkt> in: #%module-begin
. Type Checker: untyped identifier flat-named-contract imported from module <racket/contract> in: #%module-begin
. Type Checker: untyped identifier build-source-location imported from module <syntax/srcloc> in: #%module-begin
. Type Checker: Summary: 4 errors encountered in:
  #%module-begin
  #%module-begin
  #%module-begin
  #%module-begin

takikawa

plt/racket-git/collects/typed-racket/utils/tc-utils.rkt:154:0: Internal Typechecker Error: funapp with keyword args ((Unknown Type: #(struct:Keyword 952 #(struct:combined-frees #hasheq() ()) #(struct:combined-frees #hasheq() ()) #f #f #:foo Integer #t))) NYI
while typechecking:
(#%app f)
originally:
(f)

takikawa

#lang racket

(require (for-syntax syntax/parse))

(define-match-expander list-or
  (lambda (stx)
    (syntax-parse stx
      [(_ pat) #'(app (lambda (lst)
                        (for/or ([elem lst])
                          (match elem [pat elem] [_ #f])))

takikawa

$ raco pkg install pfds
=: contract violation
  expected: number?
  given: #<eof>
  argument position: 1st
  other arguments...:
   31
  context...:
   /home/asumu/plt/racket-git/collects/file/untgz.rkt:27:3
   /home/asumu/plt/racket-git/collects/planet2/lib.rkt:400:17

takikawa

#lang racket

(require rackunit)

(test-begin 
 (parameterize ([current-check-around 
                 (λ (thunk) 
                   (with-handlers ([exn? (λ (e) ((error-display-handler) "check" e))])
                     (thunk)))]) 
   (check-equal? 1 2)))

takikawa

#lang scribble/lp

@chunk[<a> (module main racket (provide x) (define x 3))]
@chunk[<b> (module test racket
             (require rackunit (submod ".." main))
             (check-equal? x 3))]
@chunk[<*> (begin <a> <b>)]

takikawa

Context: the package taglib is installed in shared scope, but not
         in the default user scope. The user is trying to remove the
         package (with the default --user option).

Old error message:

$ raco pkg remove taglib
raco pkg remove: package not currently installed
  package: taglib
  currently installed: [none]

takikawa

#lang racket

(require rackunit)

(define old-handler (current-check-handler))

(parameterize ([current-check-handler
                (λ (exn)
                  ;; put custom processing here
                  (displayln "do something")

takikawa

#lang racket

;; a fun implementation of balanced brackets from Rosetta Code
(define (balanced? str)
  (with-handlers ([exn:fail? (λ (exn) #f)])
    (define in (open-input-string str)
      (let loop ([x (read in)])
        (if (not (eof-object? x))
            (loop (read in))
            #t))))