racket/collects/scribblings/htdp-langs/intermediate-lambda.scrbl
Jay McCarthy 01a41a812e Closing pr11216. Adding one armed check-error to teaching languages.
[It will not bother me if we revert this commit. I liked SK's idea and found it easy to implement. I wonder if others will be worried that it is easy to unintentionally leave off the second argument to check-error. I also wonder if it is problematic to add new string constants, like I've done.]

Here is an example:

(check-error (/ 1 0) "/: division by zero")
(check-error (/ 1 0) "divide by zero")
(check-error (/ 1 0))
(check-error 1)

Here is the output:

Ran 4 tests.
2 of the 4 tests failed.

No signature violations.

Check failures:
	check-error encountered the following error instead of the expected divide by zero
   :: /: division by zero
in ex.rkt, line 2, column 0
	check-error expected an error, but instead received the value 1.
in ex.rkt, line 4, column 0
2010-09-16 21:00:05 -06:00

200 lines
6.0 KiB
Racket

#lang scribble/doc
@(require "common.ss"
"std-grammar.ss"
"prim-ops.ss"
(for-label lang/htdp-intermediate-lambda))
@(define-syntax-rule (bd intm-define intm-define-struct intm-local intm-letrec intm-let intm-let* intm-time)
(begin
(require (for-label lang/htdp-intermediate))
(define intm-define (scheme define))
(define intm-define-struct (scheme define-struct))
(define intm-local (scheme local))
(define intm-letrec (scheme letrec))
(define intm-let (scheme let))
(define intm-let* (scheme let*))
(define intm-time (scheme time))))
@(bd intm-define intm-define-struct intm-local intm-letrec intm-let intm-let* intm-time)
@(define-syntax-rule (bbd beg-define beg-define-struct beg-cond beg-if beg-and beg-or beg-check-expect beg-require)
(begin
(require (for-label lang/htdp-beginner))
(define beg-define (scheme define))
(define beg-define-struct (scheme define-struct))
(define beg-cond (scheme cond))
(define beg-if (scheme if))
(define beg-and (scheme and))
(define beg-or (scheme or))
(define beg-check-expect (scheme check-expect))
(define beg-require (scheme require))))
@(bbd beg-define beg-define-struct beg-cond beg-if beg-and beg-or beg-check-expect beg-require)
@title[#:style 'toc #:tag "intermediate-lam"]{Intermediate Student with Lambda}
@declare-exporting[lang/htdp-intermediate-lambda]
@schemegrammar*+qq[
#:literals (define define-struct lambda λ cond else if and or empty true false require lib planet
local let let* letrec time check-expect check-within check-error)
(check-expect check-within check-error require)
[program (code:line def-or-expr ...)]
[def-or-expr definition
expr
test-case
library-require]
[definition (define (id id id ...) expr)
(define id expr)
(define-struct id (id ...))]
[expr (lambda (id id ...) expr)
(λ (id id ...) expr)
(local [definition ...] expr)
(letrec ([id expr] ...) expr)
(let ([id expr] ...) expr)
(let* ([id expr] ...) expr)
(code:line (expr expr expr ...) (code:comment @#,seclink["intermediate-lambda-call"]{function call}))
(cond [expr expr] ... [expr expr])
(cond [expr expr] ... [else expr])
(if expr expr expr)
(and expr expr expr ...)
(or expr expr expr ...)
(time expr)
empty
(code:line id (code:comment @#,seclink["intermediate-id"]{identifier}))
(code:line prim-op (code:comment @#,seclink["intermediate-lambda-prim-op"]{primitive operation}))
(code:line @#,elem{@schemevalfont{'}@scheme[_quoted]} (code:comment @#,seclink["beginner-abbr-quote"]{quoted value}))
(code:line @#,elem{@schemevalfont{`}@scheme[_quasiquoted]} (code:comment @#,seclink["beginner-abbr-quasiquote"]{quasiquote}))
number
true
false
string
character]
]
@|prim-nonterms|
@prim-ops['(lib "htdp-intermediate-lambda.ss" "lang") #'here]
@; ----------------------------------------------------------------------
@section[#:tag "intermediate-lambda-define"]{@scheme[define]}
@deftogether[(
@defform[(define (id id id ...) expr)]
@defform/none[#:literals (define)
(define id expr)]
)]{
The same as Intermediate's @|intm-define|. No special case is needed
for @scheme[lambda], since a @scheme[lambda] form is an expression.}
@; ----------------------------------------------------------------------
@section[#:tag "intermediate-lambda"]{@scheme[lambda]}
@defform[(lambda (id id ...) expr)]{
Creates a function that takes as many arguments as given @scheme[id]s,
and whose body is @scheme[expr].}
@defform[(λ (id id ...) expr)]{
The Greek letter @scheme[λ] is a synonym for @scheme[lambda].}
@; ----------------------------------------------------------------------
@section[#:tag "intermediate-lambda-call"]{Function Calls}
@defform/none[(expr expr expr ...)]{
Like a Beginning @seclink["beginner-call"]{function call}, except that
the function position can be an arbitrary expression---perhaps a
@scheme[lambda] expression or a @scheme[_prim-op].}
@defform[(#%app expr expr expr ...)]{
A function call can be written with @scheme[#%app], though it's
practically never written that way.}
@; ----------------------------------------------------------------------
@section[#:tag "intermediate-lambda-prim-op"]{Primitive Operation Names}
@defform/none[prim-op]{
The name of a primitive operation can be used as an expression. It
produces a function version of the operation.}
@prim-op-defns['(lib "htdp-intermediate-lambda.ss" "lang") #'here '()]
@; ----------------------------------------------------------------------
@section[#:tag "intermediate-lambda-unchanged"]{Unchanged Forms}
@defform[(define-struct structid (fieldid ...))]{
The same as Intermediate's @|intm-define-struct|.}
@deftogether[(
@defform[(local [definition ...] expr)]
@defform[(letrec ([id expr-for-let] ...) expr)]
@defform[(let ([id expr-for-let] ...) expr)]
@defform[(let* ([id expr-for-let] ...) expr)]
)]{
The same as Intermediate's @|intm-local|, @|intm-letrec|, @|intm-let|,
and @|intm-let*|.}
@deftogether[(
@defform[(cond [expr expr] ... [expr expr])]
@defidform[else]
)]{
The same as Beginning's @|beg-cond|.}
@defform[(if expr expr expr)]{
The same as Beginning's @|beg-if|.}
@deftogether[(
@defform[(and expr expr expr ...)]
@defform[(or expr expr expr ...)]
)]{
The same as Beginning's @|beg-and| and @|beg-or|.}
@defform[(time expr)]{
The same as Intermediate's @|intm-time|.}
@deftogether[(
@defform[(check-expect expr expr)]
@defform[(check-within expr expr expr)]
@defform*[[(check-error expr expr)
(check-error expr)]]
@defform[(check-member-of expr expr expr ...)]
@defform[(check-range expr expr expr)]
)]{
The same as Beginning's @|beg-check-expect|, etc.}
@deftogether[(
@defthing[empty empty?]
@defthing[true boolean?]
@defthing[false boolean?]
)]{
Constants for the empty list, true, and false.}
@defform[(require module-path)]{
The same as Beginning's @|beg-require|.}