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add #:contracts optional sub-form to defform

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svn: r13012
This commit is contained in:
Matthew Flatt 2009-01-05 14:00:07 +00:00
parent 08201a309d
commit 851c58ea50
7 changed files with 219 additions and 100 deletions
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135
collects/scribble/private/manual-form.ss
View File

@ -32,6 +32,7 @@
(syntax-case stx ()
[(_ #:id defined-id #:literals (lit ...) [spec spec1 ...]
([non-term-id non-term-form ...] ...)
#:contracts ([contract-nonterm contract-expr] ...)
desc ...)
(with-syntax ([new-spec
(let loop ([spec #'spec])
@ -65,57 +66,83 @@
(lambda () (schemeblock0/form non-term-form))
...)
...)
(list (list (lambda () (scheme contract-nonterm))
(lambda () (schemeblock0 contract-expr)))
...)
(lambda () (list desc ...)))))]
[(fm #:id defined-id #:literals (lit ...) [spec spec1 ...]
([non-term-id non-term-form ...] ...)
desc ...)
(syntax/loc stx
(fm #:id defined-id #:literals (lit ...) [spec spec1 ...]
([non-term-id non-term-form ...] ...)
#:contracts ()
desc ...))]
[(fm #:id id [spec spec1 ...] ([non-term-id non-term-form ...] ...)
desc ...)
#'(fm #:id id #:literals () [spec spec1 ...]
(syntax/loc stx
(fm #:id id #:literals () [spec spec1 ...]
([non-term-id non-term-form ...] ...)
desc ...)]
#:contracts ()
desc ...))]
[(fm #:literals lits [(spec-id . spec-rest) spec1 ...]
([non-term-id non-term-form ...] ...)
desc ...)
(with-syntax ([(_ _ _ [spec . _] . _) stx])
#'(fm #:id spec-id #:literals lits [spec spec1 ...]
(syntax/loc stx
(fm #:id spec-id #:literals lits [spec spec1 ...]
([non-term-id non-term-form ...] ...)
desc ...))]
desc ...)))]
[(fm [spec spec1 ...] ([non-term-id non-term-form ...] ...) desc ...)
#'(fm #:literals () [spec spec1 ...] ([non-term-id non-term-form ...] ...)
desc ...)]))
(syntax/loc stx
(fm #:literals () [spec spec1 ...] ([non-term-id non-term-form ...] ...)
desc ...))]))
(define-syntax (defform* stx)
(syntax-case stx ()
[(_ #:id id #:literals lits [spec ...] desc ...)
#'(defform*/subs #:id id #:literals lits [spec ...] () desc ...)]
(syntax/loc stx
(defform*/subs #:id id #:literals lits [spec ...] () desc ...))]
[(_ #:literals lits [spec ...] desc ...)
#'(defform*/subs #:literals lits [spec ...] () desc ...)]
(syntax/loc stx
(defform*/subs #:literals lits [spec ...] () desc ...))]
[(_ [spec ...] desc ...)
#'(defform*/subs [spec ...] () desc ...)]))
(syntax/loc stx
(defform*/subs [spec ...] () desc ...))]))
(define-syntax (defform stx)
(syntax-case stx ()
[(_ #:id id #:literals (lit ...) spec desc ...)
#'(defform*/subs #:id id #:literals (lit ...) [spec] () desc ...)]
(syntax/loc stx
(defform*/subs #:id id #:literals (lit ...) [spec] () desc ...))]
[(_ #:id id spec desc ...)
#'(defform*/subs #:id id #:literals () [spec] () desc ...)]
(syntax/loc stx
(defform*/subs #:id id #:literals () [spec] () desc ...))]
[(_ #:literals (lit ...) spec desc ...)
#'(defform*/subs #:literals (lit ...) [spec] () desc ...)]
(syntax/loc stx
(defform*/subs #:literals (lit ...) [spec] () desc ...))]
[(_ spec desc ...)
#'(defform*/subs [spec] () desc ...)]))
(syntax/loc stx
(defform*/subs [spec] () desc ...))]))
(define-syntax (defform/subs stx)
(syntax-case stx ()
[(_ #:id id #:literals lits spec subs desc ...)
#'(defform*/subs #:id id #:literals lits [spec] subs desc ...)]
(syntax/loc stx
(defform*/subs #:id id #:literals lits [spec] subs desc ...))]
[(_ #:id id spec subs desc ...)
#'(defform*/subs #:id id #:literals () [spec] subs desc ...)]
(syntax/loc stx
(defform*/subs #:id id #:literals () [spec] subs desc ...))]
[(_ #:literals lits spec subs desc ...)
#'(defform*/subs #:literals lits [spec] subs desc ...)]
(syntax/loc stx
(defform*/subs #:literals lits [spec] subs desc ...))]
[(_ spec subs desc ...)
#'(defform*/subs [spec] subs desc ...)]))
(syntax/loc stx
(defform*/subs [spec] subs desc ...))]))
(define-syntax (defform/none stx)
(syntax-case stx ()
[(_ #:literals (lit ...) spec desc ...)
[(_ #:literals (lit ...) spec #:contracts ([contract-id contract-expr] ...) desc ...)
(begin
(for-each (lambda (id)
(unless (identifier? id)
@ -130,9 +157,16 @@
(*defforms #f
'(spec) (list (lambda (ignored) (schemeblock0/form spec)))
null null
(list (list (lambda () (scheme contract-id))
(lambda () (schemeblock0 contract-expr)))
...)
(lambda () (list desc ...)))))]
[(_ spec desc ...)
#'(defform/none #:literals () spec desc ...)]))
[(fm #:literals (lit ...) spec desc ...)
(syntax/loc stx
(fm #:literals (lit ...) spec #:contracts () desc ...))]
[(fm spec desc ...)
(syntax/loc stx
(fm #:literals () spec desc ...))]))
(define-syntax (defidform stx)
(syntax-case stx ()
@ -145,6 +179,7 @@
(list (lambda (x) (make-omitable-paragraph (list x))))
null
null
null
(lambda () (list desc ...))))]))
(define (into-blockquote s)
@ -164,6 +199,7 @@
(define-syntax spec?form/subs
(syntax-rules ()
[(_ has-kw? #:literals (lit ...) spec ([non-term-id non-term-form ...] ...)
#:contracts ([contract-nonterm contract-expr] ...)
desc ...)
(with-scheme-variables
(lit ...)
@ -175,7 +211,15 @@
(lambda () (schemeblock0/form non-term-form))
...)
...)
(lambda () (list desc ...))))]))
(list (list (lambda () (scheme contract-nonterm))
(lambda () (schemeblock0 contract-expr)))
...)
(lambda () (list desc ...))))]
[(_ has-kw? #:literals (lit ...) spec ([non-term-id non-term-form ...] ...)
desc ...)
(spec?form/subs has-kw? #:literals (lit ...) spec ([non-term-id non-term-form ...] ...)
#:contracts ()
desc ...)]))
(define-syntax specsubform
(syntax-rules ()
@ -220,7 +264,7 @@
(with-scheme-variables
()
([form/maybe (#f spec)])
(*specsubform 'spec null #f null null (lambda () (list desc ...)))))
(*specsubform 'spec null #f null null null (lambda () (list desc ...)))))
(define-syntax schemegrammar
(syntax-rules ()
@ -258,7 +302,7 @@
(define (meta-symbol? s) (memq s '(... ...+ ?)))
(define (*defforms kw-id forms form-procs subs sub-procs content-thunk)
(define (*defforms kw-id forms form-procs subs sub-procs contract-procs content-thunk)
(parameterize ([current-meta-list '(... ...+)])
(make-box-splice
(cons
@ -307,10 +351,11 @@
sub-procs)])
(*schemerawgrammars "specgrammar"
(map car l)
(map cdr l))))))))))
(map cdr l))))))))
(make-contracts-table contract-procs)))
(content-thunk)))))
(define (*specsubform form lits form-thunk subs sub-procs content-thunk)
(define (*specsubform form lits form-thunk subs sub-procs contract-procs content-thunk)
(parameterize ([current-meta-list '(... ...+)])
(make-blockquote
"leftindent"
@ -324,16 +369,18 @@
(if form-thunk
(form-thunk)
(make-omitable-paragraph (list (to-element form)))))))
(if (null? sub-procs)
null
(list (list flow-empty-line)
(list (make-flow
(list (let ([l (map (lambda (sub)
(map (lambda (f) (f)) sub))
sub-procs)])
(*schemerawgrammars "specgrammar"
(map car l)
(map cdr l))))))))))
(append
(if (null? sub-procs)
null
(list (list flow-empty-line)
(list (make-flow
(list (let ([l (map (lambda (sub)
(map (lambda (f) (f)) sub))
sub-procs)])
(*schemerawgrammars "specgrammar"
(map car l)
(map cdr l))))))))
(make-contracts-table contract-procs))))
(flow-paragraphs (decode-flow (content-thunk)))))))
(define (*schemerawgrammars style nonterms clauseses)
@ -374,3 +421,21 @@
(define (*var-sym id)
(string->symbol (format "_~a" id)))
(define (make-contracts-table contract-procs)
(if (null? contract-procs)
null
(append
(list (list flow-empty-line))
(list (list (make-flow
(map (lambda (c)
(make-table
"argcontract"
(list
(list (to-flow (hspace 2))
(to-flow ((car c)))
flow-spacer
(to-flow ":")
flow-spacer
(make-flow (list ((cadr c))))))))
contract-procs)))))))

2
collects/scribblings/quick/quick.scrbl
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@ -410,7 +410,7 @@ Modules are named and distributed in various ways:
@item{Some modules live relative to other modules, without
necessarily belonging to any particular collection or package.
For example, in DrScheme, if save your definitions so far in a
For example, in DrScheme, if you save your definitions so far in a
file @filepath{quick.ss} and add the line
@schemeblock[(provide rainbow square)]

9
collects/scribblings/reference/for.scrbl
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@ -14,7 +14,8 @@ The @scheme[for] iteration forms are based on SRFI-42
@defform/subs[(for (for-clause ...) body ...+)
([for-clause [id seq-expr]
[(id ...) seq-expr]
(code:line #:when guard-expr)])]{
(code:line #:when guard-expr)])
#:contracts ([seq-expr sequence?])]{
Iteratively evaluates @scheme[body]. The @scheme[for-clause]s
introduce bindings whose scope includes @scheme[body] and that
@ -242,7 +243,11 @@ Like @scheme[for*/fold], but the extra @scheme[orig-datum] is used as the source
@defform[(define-sequence-syntax id
expr-transform-expr
clause-transform-expr)]{
clause-transform-expr)
#:contracts
([expr-transform-expr (or/c (-> identifier?)
(syntax? . -> . syntax?))]
[clause-transform-expr (syntax? . -> . syntax?)])]{
Defines @scheme[id] as syntax. An @scheme[(id . _rest)] form is
treated specially when used to generate a sequence in a

4
collects/scribblings/reference/parameters.scrbl
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@ -45,7 +45,9 @@ reject a change to the parameter's value. The @scheme[guard] is not
applied to the initial @scheme[v].}
@defform[(parameterize ((parameter-expr value-expr) ...)
body ...+)]{
body ...+)
#:contracts
([parameter-expr parameter?])]{
@guideintro["parameterize"]{@scheme[parameterize]}

25
collects/scribblings/reference/syntax.scrbl
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@ -28,9 +28,11 @@ See @secref["fully-expanded"] for the core grammar.
Each syntactic form is described by a BNF-like notation that describes
a combination of (syntax-wrapped) pairs, symbols, and other data (not
a sequence of characters). These grammatical specifications are shown
as follows:
as in the following specification of a @schemekeywordfont{something}
form:
@specsubform[(#, @schemekeywordfont{some-form} id ...)]
@specsubform[(#, @schemekeywordfont{something} id thing-expr ...)
#:contracts ([thing-expr number?])]
Within such specifications,
@ -42,26 +44,31 @@ Within such specifications,
@item{@scheme[...+] indicates one or
more repetitions of the preceding datum.}
@item{italic meta-identifiers play the role of non-terminals; in
particular,
@item{Italic meta-identifiers play the role of non-terminals. Some
meta-identifier names imply syntactic constraints:
@itemize{
@item{a meta-identifier that ends in @scheme[_id] stands for an
@item{A meta-identifier that ends in @scheme[_id] stands for an
identifier.}
@item{a meta-identifier that ends in @scheme[_keyword] stands
@item{A meta-identifier that ends in @scheme[_keyword] stands
for a keyword.}
@item{a meta-identifier that ends with @scheme[_expr] stands
for a sub-form that is expanded as an expression.}
@item{A meta-identifier that ends with @scheme[_expr] (such as
@scheme[_thing-expr]) stands for a sub-form that is
expanded as an expression.}
@item{A meta-identifier that ends with @scheme[_body] stands
for a sub-form that is expanded in an
internal-definition context (see
@secref["intdef-body"]).}
}} }
}}
@item{Contracts indicate constraints on sub-expression results. For
example, @scheme[_thing-expr #, @elem{:} number?] indicates that
the expression @scheme[_thing-expr] must produce a number.}}
@;------------------------------------------------------------------------
@section[#:tag "module"]{Modules: @scheme[module], ...}

39
collects/scribblings/scribble/manual.scrbl
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@ -387,15 +387,19 @@ can also be defined by a single @scheme[defproc*], for the case that
it's best to document a related group of procedures at once.}
@defform/subs[(defform maybe-id maybe-literals form-datum pre-flow ...)
@defform/subs[(defform maybe-id maybe-literals form-datum maybe-contracts
pre-flow ...)
([maybe-id code:blank
(code:line #:id id)]
[maybe-literals code:blank
(code:line #:literals (literal-id ...))])]{
(code:line #:literals (literal-id ...))]
[maybe-contracts code:blank
(code:line #:contracts ([subform-datum contract-expr-datum]
...))])]{
Produces a sequence of flow elements (encapsulated in a
@scheme[splice]) to document a syntatic form named by @scheme[id]
whose syntax described by @scheme[form-datum]. If no @scheme[#:id] is used
whose syntax is described by @scheme[form-datum]. If no @scheme[#:id] is used
to specify @scheme[id], then @scheme[form-datum] must have the form
@scheme[(id . _datum)].
@ -414,16 +418,24 @@ non-terminal. If @scheme[#:literals] clause is provided, however,
instances of the @scheme[literal-id]s are typeset normally (i.e., as
determined by the enclosing context).
The typesetting of @scheme[form-datum] preserves the source layout,
like @scheme[schemeblock].}
If a @scheme[#:contracts] clause is provided, each
@scheme[subform-datum] (typically an identifier that serves as a
meta-variable in @scheme[form-datum]) is shown as producing a value
that must satisfy the contract described by @scheme[contract-expr-datum].
@defform[(defform* maybe-id maybe-literals [form-datum ...+] pre-flow ...)]{
The typesetting of @scheme[form-datum], @scheme[subform-datum], and
@scheme[contract-expr-datum] preserves the source layout, like
@scheme[schemeblock].}
@defform[(defform* maybe-id maybe-literals [form-datum ...+] maybe-contracts
pre-flow ...)]{
Like @scheme[defform], but for multiple forms using the same
@scheme[_id].}
@defform[(defform/subs maybe-id maybe-literals form-datum
([nonterm-id clause-datum ...+] ...)
maybe-contracts
pre-flow ...)]{
Like @scheme[defform], but including an auxiliary grammar of
@ -434,12 +446,14 @@ non-terminals shown with the @scheme[_id] form. Each
@defform[(defform*/subs maybe-id maybe-literals [form-datum ...]
maybe-contracts
pre-flow ...)]{
Like @scheme[defform/subs], but for multiple forms for @scheme[_id].}
@defform[(defform/none maybe-literal form-datum pre-flow ...)]{
@defform[(defform/none maybe-literal form-datum maybe-contracts
pre-flow ...)]{
Like @scheme[defform], but without registering a definition.}
@ -449,14 +463,16 @@ Like @scheme[defform], but without registering a definition.}
Like @scheme[defform], but with a plain @scheme[id] as the form.}
@defform[(specform maybe-literals datum pre-flow ...)]{
@defform[(specform maybe-literals datum maybe-contracts
pre-flow ...)]{
Like @scheme[defform], but without indexing or registering a
definition, and with indenting on the left for both the specification
and the @scheme[pre-flow]s.}
@defform[(specsubform maybe-literals datum pre-flow ...)]{
@defform[(specsubform maybe-literals datum maybe-contracts
pre-flow ...)]{
Similar to @scheme[defform], but without any specific identifier being
defined, and the table and flow are typeset indented. This form is
@ -472,13 +488,15 @@ procedure. In this description, a reference to any identifier in
@defform[(specsubform/subs maybe-literals datum
([nonterm-id clause-datum ...+] ...)
maybe-contracts
pre-flow ...)]{
Like @scheme[specsubform], but with a grammar like
@scheme[defform/subs].}
@defform[(specspecsubform maybe-literals datum pre-flow ...)]{
@defform[(specspecsubform maybe-literals datum maybe-contracts
pre-flow ...)]{
Like @scheme[specsubform], but indented an extra level. Since using
@scheme[specsubform] within the body of @scheme[specsubform] already
@ -488,6 +506,7 @@ without nesting a description.}
@defform[(specspecsubform/subs maybe-literals datum
([nonterm-id clause-datum ...+] ...)
maybe-contracts
pre-flow ...)]{
Like @scheme[specspecsubform], but with a grammar like

105
collects/teachpack/2htdp/scribblings/universe.scrbl
View File

@ -188,22 +188,24 @@ The design of a world program demands that you come up with a data
@itemize[
@item{
@defform[(on-tick
[tick-expr (-> (unsyntax @tech{World}) (unsyntax @tech{World}))])]{
@defform[(on-tick tick-expr)
#:contracts
([tick-expr (-> (unsyntax @tech{World}) (unsyntax @tech{World}))])]{
tell DrScheme to call the @scheme[tick-expr] function on the current
world every time the clock ticks. The result of the call becomes the
current world. The clock ticks at the rate of 28 times per second.}}
@item{
@defform/none[(on-tick
[tick-expr (-> (unsyntax @tech{World}) (unsyntax @tech{World}))]
@defform/none[(on-tick tick-expr rate-expr)
#:contracts
([tick-expr (-> (unsyntax @tech{World}) (unsyntax @tech{World}))]
[rate-expr natural-number/c])]{
tell DrScheme to call the @scheme[tick-expr] function on the current
world every time the clock ticks. The result of the call becomes the
current world. The clock ticks at the rate of @scheme[rate-expr].}}
@item{An @tech{KeyEvent} represents key board events, e.g., keys pressed or
@item{A @tech{KeyEvent} represents key board events, e.g., keys pressed or
released.
@deftech{KeyEvent} : @scheme[(or/c char? symbol?)]
@ -230,8 +232,9 @@ A character is used to signal that the user has hit an alphanumeric
@defproc[(key=? [x key-event?][y key-event?]) boolean?]{
compares two @tech{KeyEvent} for equality}
@defform[(on-key
[change-expr (-> (unsyntax @tech{World}) key-event? (unsyntax @tech{World}))])]{
@defform[(on-key change-expr)
#:contracts
([change-expr (-> (unsyntax @tech{World}) key-event? (unsyntax @tech{World}))])]{
tell DrScheme to call @scheme[change-expr] function on the current world and a
@tech{KeyEvent} for every keystroke the user of the computer makes. The result
of the call becomes the current world.
@ -282,8 +285,9 @@ All @tech{MouseEvent}s are represented via symbols:
@defproc[(mouse=? [x mouse-event?][y mouse-event?]) boolean?]{
compares two @tech{KeyEvent} for equality}
@defform[(on-mouse
[clack-expr
@defform[(on-mouse clack-expr)
#:contracts
([clack-expr
(-> (unsyntax @tech{World}) natural-number/c natural-number/c (unsyntax @tech{MouseEvent}) (unsyntax @tech{World}))])]{
tell DrScheme to call @scheme[clack-expr] on the current world, the current
@scheme[x] and @scheme[y] coordinates of the mouse, and and a
@ -297,16 +301,18 @@ All @tech{MouseEvent}s are represented via symbols:
@item{
@defform[(on-draw
[render-expr (-> (unsyntax @tech{World}) scene?)])]{
@defform[(on-draw render-expr)
#:contracts
([render-expr (-> (unsyntax @tech{World}) scene?)])]{
tell DrScheme to call the function @scheme[render-expr] whenever the
canvas must be drawn. The external canvas is usually re-drawn after DrScheme has
dealt with an event. Its size is determined by the size of the first
generated @tech{scene}.}
@defform/none[(on-draw
[render-expr (-> (unsyntax @tech{World}) scene?)]
@defform/none[(on-draw render-expr width-expr height-expr)
#:contracts
([render-expr (-> (unsyntax @tech{World}) scene?)]
[width-expr natural-number/c]
[height-expr natural-number/c])]{
@ -317,8 +323,9 @@ All @tech{MouseEvent}s are represented via symbols:
@item{
@defform[(stop-when
[last-world? (-> (unsyntax @tech{World}) boolean?)])]{
@defform[(stop-when last-world?)
#:contracts
([last-world? (-> (unsyntax @tech{World}) boolean?)])]{
tell DrScheme to call the @scheme[last-world?] function whenever the canvas is
drawn. If this call produces @scheme[true], the world program is shut
down. Specifically, the clock is stopped; no more
@ -328,8 +335,9 @@ All @tech{MouseEvent}s are represented via symbols:
@item{
@defform[(record?
[boolean-expr boolean?])]{
@defform[(record? boolean-expr)
#:contracts
([boolean-expr boolean?])]{
tell DrScheme to record all events and to enable a replay of the entire
interaction. The replay action also generates one png image per scene and
an animated gif for the entire sequence.
@ -728,21 +736,25 @@ Each world-producing callback in a world program---those for handling clock
As mentioned, all event handlers may return @tech{World}s or @tech{Package}s;
here are the revised specifications:
@defform/none[(on-tick
[tick-expr (-> (unsyntax @tech{World}) (or/c (unsyntax @tech{World}) package?))])]{
@defform/none[(on-tick tick-expr)
#:contracts
([tick-expr (-> (unsyntax @tech{World}) (or/c (unsyntax @tech{World}) package?))])]{
}
@defform/none[(on-tick
[tick-expr (-> (unsyntax @tech{World}) (or/c (unsyntax @tech{World}) package?))]
@defform/none[(on-tick tick-expr rate-expr)
#:contracts
([tick-expr (-> (unsyntax @tech{World}) (or/c (unsyntax @tech{World}) package?))]
[rate-expr natural-number/c])]{
}
@defform/none[(on-key
[change (-> (unsyntax @tech{World}) key-event? (or/c (unsyntax @tech{World}) package?))])]{
@defform/none[(on-key change-expr)
#:contracts
([change-expr (-> (unsyntax @tech{World}) key-event? (or/c (unsyntax @tech{World}) package?))])]{
}
@defform/none[(on-mouse
[clack
@defform/none[(on-mouse clack-expr)
#:contracts
([clack-expr
(-> (unsyntax @tech{World}) natural-number/c natural-number/c (unsyntax @tech{MouseEvent})
(or/c (unsyntax @tech{World}) package?))])]{
}
@ -780,14 +792,16 @@ following shapes:
@itemize[
@item{
@defform[(register [ip-expr string?])]{
@defform[(register ip-expr) #:contracts ([ip-expr string?])]{
connect this world to a universe server at the specified @scheme[ip-expr]
address and set up capabilities for sending and receiving messages.}
}
@item{
@defform/none[(register [ip-expr string?]
[name-expr (or/c symbol? string?)])]{
@defform/none[(register ip-expr name-expr)
#:contracts
([ip-expr string?]
[name-expr (or/c symbol? string?)])]{
connect this world to a universe server @emph{under a specific} @scheme[name-expr].}
}
@ -807,8 +821,9 @@ Finally, the receipt of a message from the server is an event, just like
The @scheme[on-receive] clause of a @scheme[big-bang] specifies the event handler
for message receipts.
@defform[(on-receive
[receive-expr (-> (unsyntax @tech{World}) sexp? (or/c (unsyntax @tech{World}) package?))])]{
@defform[(on-receive receive-expr)
#:contracts
([receive-expr (-> (unsyntax @tech{World}) sexp? (or/c (unsyntax @tech{World}) package?))])]{
tell DrScheme to call @scheme[receive-expr] for every message receipt, on the current
@tech{World} and the received message. The result of the call becomes the current
@tech{World}.
@ -993,15 +1008,17 @@ description. Two of them are mandatory:
@itemize[
@item{
@defform[(on-new
[new-expr (-> (unsyntax @tech{Universe}) world?
@defform[(on-new new-expr)
#:contracts
([new-expr (-> (unsyntax @tech{Universe}) world?
(cons (unsyntax @tech{Universe}) [listof mail?]))])]{
tell DrScheme to call the function @scheme[new-expr] every time another world joins the
universe.}}
@item{
@defform[(on-msg
[msg-expr (-> (unsyntax @tech{Universe}) world? sexp?
@defform[(on-msg msg-expr)
#:contracts
([msg-expr (-> (unsyntax @tech{Universe}) world? sexp?
(cons (unsyntax @tech{Universe}) [listof mail?]))])]{
tell DrScheme to apply @scheme[msg-expr] to the current state of the universe, the world
@ -1020,15 +1037,17 @@ optional handlers:
@itemize[
@item{
@defform/none[(on-tick
[tick-expr (-> (unsyntax @tech{Universe}) bundle?)])]{
@defform/none[(on-tick tick-expr)
#:contracts
([tick-expr (-> (unsyntax @tech{Universe}) bundle?)])]{
tell DrScheme to apply @scheme[tick-expr] to the current state of the
universe. The handler is expected to produce a bundle of the new state of
the universe and a list of mails.
}
@defform/none[(on-tick
[tick-expr (-> (unsyntax @tech{Universe}) bundle?)]
@defform/none[(on-tick tick-expr rate-expr)
#:contracts
([tick-expr (-> (unsyntax @tech{Universe}) bundle?)]
[rate-expr natural-number/c])]{
tell DrScheme to apply @scheme[tick-expr] as above but use the specified
clock tick rate instead of the default.
@ -1036,8 +1055,9 @@ optional handlers:
}
@item{
@defform[(on-disconnect
[dis-expr (-> (unsyntax @tech{Universe}) world? bundle?)])]{
@defform[(on-disconnect dis-expr)
#:contracts
([dis-expr (-> (unsyntax @tech{Universe}) world? bundle?)])]{
tell DrScheme to invoke @scheme[dis-expr] every time a participating
@tech{world} drops its connection to the server. The first argument is the
current state of the universe; the second one is the world that got
@ -1046,8 +1066,9 @@ optional handlers:
}
@item{
@defform[(to-string
[render-expr (-> (unsyntax @tech{Universe}) string?)])]{
@defform[(to-string render-expr)
#:contracts
([render-expr (-> (unsyntax @tech{Universe}) string?)])]{
tell DrScheme to render the state of the universe after each event and to
display this string in the universe console.
}