start txtadv tutorial

dev-elider-3
Matthew Butterick 8 years ago
parent 6a5e7a8366
commit 2d2ac10654

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#lang br
(module+ reader
(require "txtadv/reader.rkt")
(provide (all-from-out "txtadv/reader.rkt")))

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#lang racket/base
(require parser-tools/lex
syntax-color/scheme-lexer
(prefix-in : parser-tools/lex-sre))
(provide color-lexer)
(define-lex-abbrevs
[id (:: (:/ #\A #\Z #\a #\z) (:* (:or (:/ #\A #\Z #\a #\z #\0 #\9) #\-)))]
[digit8 (:/ "0" "7")]
[digit16 (:/ "af" "AF" "09")]
[unicode (:or (:: "u" (:** 1 4 digit16))
(:: "U" (:** 1 6 digit16)))]
[str (:: "\"" (:* string-element (:: "\\" unicode)) "\"")]
[string-element (:or (:~ "\"" "\\")
"\\\""
"\\\\"
"\\a"
"\\b"
"\\t"
"\\n"
"\\v"
"\\f"
"\\r"
"\\e"
"\\'"
(:: "\\" (:** 1 3 digit8))
(:: "\\x" (:** 1 2 digit16))
(:: "\\" #\newline))])
(define errors
(lexer
[any-char
(values lexeme 'error #f (position-offset start-pos) (position-offset end-pos)
1 (list inc-errors 1))]
[(eof)
(values lexeme 'eof #f #f #f 0 #f)]))
(define (inc-errors in back)
(define-values (lexeme type data new-token-start new-token-end backup mode)
(errors in))
(values lexeme type data new-token-start new-token-end
(+ 1 (car back))
(list inc-errors (+ 1 (car back)))))
(define-syntax-rule (lexer/error [pat (_values kind next)] ...)
(lexer
[pat
(values lexeme kind #f (position-offset start-pos) (position-offset end-pos) 0 next)]
...
[any-char
(values lexeme 'error #f (position-offset start-pos) (position-offset end-pos) 0 errors)]
[(eof)
(values lexeme 'eof #f #f #f 0 #f)]))
(define-syntax-rule (lexer/whitespace ws clause ...)
(lexer/error
[(:+ whitespace)
(values lexeme ws)]
clause ...))
(define section-color 'other)
(define id-color 'symbol)
(define start
(lexer/whitespace
#f
["===VERBS===" (values section-color verbs)]))
(define verbs
(lexer/whitespace
verbs
[id (values id-color verb-trans)]
["===EVERYWHERE===" (values section-color everywhere)]))
(define verb-trans
(lexer/whitespace
verb-body
[" _" (values 'symbol verb-comma)]
[", " (values 'other verbs)]))
(define verb-comma
(lexer/whitespace
verb-body
[", " (values 'other verbs)]))
(define verb-body
(lexer/whitespace
verb-body
[str (values 'string verbs)]
[id (values id-color verb-trans)]
["===EVERYWHERE===" (values section-color everywhere)]))
(define everywhere
(lexer/whitespace
everywhere
[id (values id-color (list global-action))]
["===THINGS===" (values section-color things)]))
(define things
(lexer/whitespace
things
[(:: "---" id "---") (values id-color thing-operations)]
["===PLACES===" (values section-color places)]))
(define thing-operations
(lexer/whitespace
thing-operations
[id (values id-color (list thing-action))]
[(:: "---" id "---") (values id-color thing-operations)]
["===PLACES===" (values section-color places)]))
(define places
(lexer/whitespace
places
[(:: "---" id "---") (values id-color place)]))
(define place
(lexer/whitespace
place
[str (values 'string place-things)]))
(define place-things
(lexer/whitespace
place-things
["[" (values 'string place-thing-seq)]))
(define place-thing-seq
(lexer/whitespace
errors
[id (values id-color place-thing-seq-next)]
["]" (values 'string place-operations)]))
(define place-thing-seq-next
(lexer/whitespace
errors
[", " (values 'other place-thing-seq)]
["]" (values 'string place-operations)]))
(define place-operations
(lexer/whitespace
place-operations
[(:: "---" id "---") (values id-color place)]
[id (values id-color (list place-action))]))
(define (global-action in mode)
(action in mode global-action everywhere))
(define (thing-action in mode)
(action in mode thing-action thing-operations))
(define (place-action in mode)
(action in mode place-action place-operations))
(define (action in mode self next)
(define-values (lexeme type data new-token-start new-token-end status)
(scheme-lexer/status in))
(let ([mode (next-mode mode type data status)])
(values lexeme
(if (eq? mode 'error) 'error type)
data new-token-start new-token-end 0
(cond
[(list? mode) (cons self mode)]
[(eq? mode 'error) errors]
[else next]))))
(define (next-mode mode type data status)
(case type
[(parenthesis)
(case data
[(|(|) (cons '|)| mode)]
[(|[|) (cons '|]| mode)]
[(|{|) (cons '|}| mode)]
[else (if (and (pair? mode)
(eq? (car mode) data))
(if (and (null? (cdr mode))
(not (eq? status 'continue)))
'done
(cdr mode))
'error)])]
[(white-space comment) mode]
[else (if (and (null? mode)
(not (eq? status 'continue)))
'done
mode)]))
(define (color-lexer in offset mode)
(cond
[(not mode) (start in)]
[(pair? mode)
((car mode) in (cdr mode))]
[else
(mode in)]))

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#lang racket
(provide define-verbs
define-thing
define-place
define-everywhere
show-current-place
show-inventory
save-game
load-game
show-help
have-thing?
take-thing!
drop-thing!
thing-state
set-thing-state!
(except-out (all-from-out racket) #%module-begin)
(rename-out [module-begin #%module-begin]))
;; ============================================================
;; Overall module:
(define-syntax module-begin
(syntax-rules (define-verbs define-everywhere)
[(_ (define-verbs all-verbs cmd ...)
(define-everywhere everywhere-actions act ...)
decl ...
id)
(#%module-begin
(define-verbs all-verbs cmd ...)
(define-everywhere everywhere-actions act ...)
decl ...
(init-game (check-type id "place")
all-verbs
everywhere-actions)
(provide do-verb do-place)
(module+ main
(cmd-line-mode? #t)
(do-place)))]))
;; ============================================================
;; Model:
;; Elements of the world:
(struct verb (aliases ; list of symbols
desc ; string
transitive?)) ; boolean
(struct thing (name ; symbol
[state #:mutable] ; any value
actions)) ; list of verb--thunk pairs
(struct place (desc ; string
[things #:mutable] ; list of things
actions)) ; list of verb--thunk pairs
;; Tables mapping names<->things for save and load
(define names (make-hash))
(define elements (make-hash))
(define (record-element! name val)
(hash-set! names name val)
(hash-set! elements val name))
(define (name->element name) (hash-ref names name #f))
(define (element->name obj) (hash-ref elements obj #f))
;; ============================================================
;; Simple type layer:
(begin-for-syntax
(struct typed (id type)
#:property prop:procedure (λ (self stx) (typed-id self))
#:omit-define-syntaxes))
(define-syntax (check-type stx)
(syntax-case stx ()
[(_ id type)
(let ([v (and (identifier? #'id)
(syntax-local-value #'id (λ _ #f)))])
(unless (and (typed? v)
(equal? (syntax-e #'type) (typed-type v)))
(raise-syntax-error
#f
(format "not defined as ~a" (syntax-e #'type))
#'id))
#'id)]))
;; ============================================================
;; Macros for constructing and registering elements:
(define-syntax-rule (define-verbs all-id
[id spec ...] ...)
(begin
(define-one-verb id spec ...) ...
(record-element! 'id id) ...
(define all-id (list id ...))))
(define-syntax define-one-verb
(syntax-rules (= _)
[(define-one-verb id (= alias ...) desc)
(begin
(define gen-id (verb (list 'id 'alias ...) desc #f))
(define-syntax id (typed #'gen-id "intransitive verb")))]
[(define-one-verb id _ (= alias ...) desc)
(begin
(define gen-id (verb (list 'id 'alias ...) desc #t))
(define-syntax id (typed #'gen-id "transitive verb")))]
[(define-one-verb id)
(define-one-verb id (=) (symbol->string 'id))]
[(define-one-verb id _)
(define-one-verb id _ (=) (symbol->string 'id))]))
(define-syntax-rule (define-thing id
[vrb expr] ...)
(begin
(define gen-id
(thing 'id #f (list (cons (check-type vrb "transitive verb")
(λ _ expr)) ...)))
(define-syntax id (typed #'gen-id "thing"))
(record-element! 'id id)))
(define-syntax-rule (define-place id
desc
(thng ...)
([vrb expr] ...))
(begin
(define gen-id
(place desc
(list (check-type thng "thing") ...)
(list (cons (check-type vrb "intransitive verb")
(λ _ expr))
...)))
(define-syntax id (typed #'gen-id "place"))
(record-element! 'id id)))
(define-syntax-rule (define-everywhere id ([vrb expr] ...))
(define id (list (cons (check-type vrb "intransitive verb")
(λ _ expr))
...)))
;; ============================================================
;; Game state
(define cmd-line-mode? (make-parameter #f))
;; Initialized on startup:
(define all-verbs null) ; list of verbs
(define everywhere-actions null) ; list of verb--thunk pairs
;; Things carried by the player:
(define stuff null) ; list of things
;; Current location:
(define current-place #f) ; place (or #f until started)
;; Fuctions to be used by verb responses:
(define (have-thing? t)
(memq t stuff))
(define (take-thing! t)
(set-place-things! current-place (remq t (place-things current-place)))
(set! stuff (cons t stuff)))
(define (drop-thing! t)
(set-place-things! current-place (cons t (place-things current-place)))
(set! stuff (remq t stuff)))
;; ============================================================
;; Game execution
;; Show the player the current place, then get a command:
(define (do-place)
(show-current-place)
(when (cmd-line-mode?)
(do-verb)))
;; Show the current place:
(define (show-current-place)
(printf "~a\n" (place-desc current-place))
(for-each (λ (thing)
(printf "There is a ~a here.\n" (thing-name thing)))
(place-things current-place)))
;; Get and handle a command:
(define (get-line)
(printf "> ")
(flush-output)
(read-line))
(define (do-verb [line (and (cmd-line-mode?) (get-line))])
(define input (if (eof-object? line)
'(quit)
(let ([port (open-input-string line)])
(for/list ([v (in-port read port)]) v))))
(if (and (list? input)
(andmap symbol? input)
(<= 1 (length input) 2))
(let* ([vrb (car input)]
[response
(cond
[(= 2 (length input))
(handle-transitive-verb vrb (cadr input))]
[(= 1 (length input))
(handle-intransitive-verb vrb)])]
[result (response)])
(cond
[(place? result)
(set! current-place result)
(do-place)]
[(string? result)
(printf "~a\n" result)
(when (cmd-line-mode?) (do-verb))]
[else (when (cmd-line-mode?) (do-verb))]))
(begin
(printf "I don't undertand what you mean.\n")
(when (cmd-line-mode?) (do-verb)))))
;; Handle an intransitive-verb command:
(define (handle-intransitive-verb verb)
(or
(find-verb verb (place-actions current-place))
(find-verb verb everywhere-actions)
(using-verb
verb all-verbs
(λ (verb)
(λ _ (if (verb-transitive? verb)
(format "~a what?" (string-titlecase (verb-desc verb)))
(format "Can't ~a here." (verb-desc verb))))))
(λ _ (format "I don't know how to ~a." verb))))
;; Handle a transitive-verb command:
(define (handle-transitive-verb vrb obj)
(or (using-verb
vrb all-verbs
(λ (verb)
(and
(verb-transitive? verb)
(cond
[(ormap (λ (thing)
(and (eq? (thing-name thing) obj)
thing))
(append (place-things current-place)
stuff))
=> (λ (thing)
(or (find-verb vrb (thing-actions thing))
(λ _
(format "Don't know how to ~a ~a."
(verb-desc verb) obj))))]
[else
(λ _ (format "There's no ~a here to ~a." obj
(verb-desc verb)))]))))
(λ _ (format "I don't know how to ~a ~a." vrb obj))))
;; Show what the player is carrying:
(define (show-inventory)
(printf "You have")
(if (null? stuff)
(printf " no items.")
(for-each (λ (thing)
(printf "\n a ~a" (thing-name thing)))
stuff))
(printf "\n"))
;; Look for a command match in a list of verb--response pairs,
;; and returns the response thunk if a match is found:
(define (find-verb cmd actions)
(ormap (λ (a)
(and (memq cmd (verb-aliases (car a)))
(cdr a)))
actions))
;; Looks for a command in a list of verbs, and
;; applies `success-k' to the verb if one is found:
(define (using-verb cmd verbs success-k)
(ormap (λ (vrb)
(and (memq cmd (verb-aliases vrb))
(success-k vrb)))
verbs))
;; Print help information:
(define (show-help)
(printf "Use `look' to look around.\n")
(printf "Use `inventory' to see what you have.\n")
(printf "Use `save' or `load' to save or restore your game.\n")
(printf "There are some other verbs, and you can name a thing after some verbs.\n"))
;; ============================================================
;; Save and load
;; Prompt the user for a filename and apply `proc' to it,
;; catching errors to report a reasonably nice message:
(define (with-filename proc)
(printf "File name: ")
(flush-output)
(let ([v (read-line)])
(unless (eof-object? v)
(with-handlers ([exn? (λ (exn)
(printf "~a\n" (exn-message exn)))])
(unless (path-string? v)
(raise-user-error "bad filename"))
(proc v)))))
;; Save the current game state:
(define (save-game)
(with-filename
(λ (v)
(with-output-to-file v
(λ _
(write
(list
(map element->name stuff)
(element->name current-place)
(hash-map names
(λ (k v)
(cons k
(cond
[(place? v) (map element->name (place-things v))]
[(thing? v) (thing-state v)]
[else #f])))))))))))
;; Restore a game state:
(define (load-game)
(with-filename
(λ (v)
(let ([v (with-input-from-file v read)])
(set! stuff (map name->element (car v)))
(set! current-place (name->element (cadr v)))
(for-each
(λ (p)
(let ([v (name->element (car p))]
[state (cdr p)])
(cond
[(place? v) (set-place-things! v (map name->element state))]
[(thing? v) (set-thing-state! v state)])))
(caddr v))))))
;; ============================================================
;; To go:
(define (init-game in-place
in-all-verbs
in-everywhere-actions)
(set! current-place in-place)
(set! all-verbs in-all-verbs)
(set! everywhere-actions in-everywhere-actions))

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#lang br
(module+ reader
(require "reader.rkt")
(provide (all-from-out "reader.rkt")))

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#lang racket
(require syntax/readerr)
(provide (rename-out [txtadv-read-syntax read-syntax])
;; added at the end to link syntax to colorer:
get-info)
(define (txtadv-read-syntax src in)
(expect-section src in "VERBS")
(define verbs (in-section src in read-verb))
(expect-section src in "EVERYWHERE")
(define actions (in-section src in read-action))
(expect-section src in "THINGS")
(define things (in-section src in read-thing))
(expect-section src in "PLACES")
(define places (in-section src in read-place))
(datum->syntax
#f
`(module world br/demo/txtadv/expander
(define-verbs all-verbs
,@verbs)
(define-everywhere everywhere-actions
,actions)
,@things
,@places
,(if (null? places)
(complain src in "no places defined")
(cadar places)))))
(define (complain src in msg)
(define-values (line col pos) (port-next-location in))
(raise-read-error msg src line col pos 1))
(define (skip-whitespace in)
(regexp-try-match #px"^\\s+" in))
(define (expect-section src in name)
(skip-whitespace in)
(unless (regexp-match-peek (pregexp (format "^===~a===\\s" name))
in)
(complain src in (format "expected a ===~a=== section" name)))
(read-line in)
(read-line in))
(define (in-section src in reader)
(skip-whitespace in)
(if (or (regexp-match-peek #rx"^===" in)
(eof-object? (peek-byte in)))
null
(cons (reader src in)
(in-section src in reader))))
(define (in-defn src in reader)
(skip-whitespace in)
(if (or (regexp-match-peek #rx"^(===|---)" in)
(eof-object? (peek-byte in)))
null
(cons (reader src in)
(in-defn src in reader))))
(define (read-name src in)
(if (regexp-match-peek #px"^[A-Za-z-]+(?=:$|\\s|[],])" in)
(read-syntax src in)
(complain src in "expected a name")))
(define (read-name-sequence src in transitive)
(let loop ([names null] [transitive transitive])
(define s (read-name src in))
(define is-trans?
(cond
[(regexp-match-peek #rx"^ _" in)
(if (or (eq? transitive 'unknown)
(eq? transitive #t))
(begin
(read-char in)
(read-char in)
#t)
(begin
(read-char in)
(complain src in "unexpected underscore")))]
[else
(if (eq? transitive #t)
(complain src in "inconsistent transitivity")
#f)]))
(if (regexp-match-peek #rx"^, " in)
(begin
(read-char in)
(read-char in)
(loop (cons s names) is-trans?))
(values (reverse (cons s names)) is-trans?))))
(define (read-verb src in)
(skip-whitespace in)
(define-values (names is-transitive?)
(read-name-sequence src in 'unknown))
(skip-whitespace in)
(define desc
(if (regexp-match-peek #rx"^\"" in)
(read-syntax src in)
(symbol->string (syntax-e (car names)))))
`[,(car names)
,@(if is-transitive? '(_) '())
(= ,@(cdr names))
,desc])
(define (read-action src in)
(skip-whitespace in)
(define name (read-name src in))
(define expr (read-syntax src in))
`[,name ,expr])
(define (read-defn-name src in what)
(skip-whitespace in)
(unless (regexp-match-peek #px"^---[A-Za-z][A-Za-z0-9-]*---\\s"
in)
(complain src in (format "expected a ~a definition of the form ---name---" what)))
(read-string 3 in)
(define-values (line col pos) (port-next-location in))
(define name-str (bytes->string/utf-8 (cadr (regexp-match #px"^(.*?)---\\s" in))))
(datum->syntax #f
(string->symbol name-str)
(vector src line col pos (string-length name-str))
orig-props))
(define orig-props (read-syntax 'src (open-input-string "orig")))
(define (read-thing src in)
(define name (read-defn-name src in "thing"))
(define actions (in-defn src in read-action))
`(define-thing ,name
,@actions))
(define (read-place src in)
(define name (read-defn-name src in "place"))
(skip-whitespace in)
(define desc (if (regexp-match-peek #rx"^\"" in)
(read-syntax src in)
(complain src in "expected description string")))
(skip-whitespace in)
(unless (regexp-match-peek #rx"^[[]" in)
(complain src in "expected a square bracket to start a list of things for a place"))
(read-char in)
(define-values (things _)
(if (regexp-match-peek #rx"^[]]" in)
(values null #f)
(read-name-sequence src in #f)))
(unless (regexp-match-peek #rx"^[]]" in)
(complain src in "expected a square bracket to end a list of things for a place"))
(read-char in)
(define actions (in-defn src in read-action))
`(define-place ,name ,desc ,things ,actions))
;; DrRacket asks `get-info' for a 'color-lexer module:
(require racket/runtime-path)
(define-runtime-path color-lexer-path "color.rkt")
(define (get-info in mod line col pos)
(lambda (key default)
(case key
[(color-lexer)
(dynamic-require color-lexer-path 'color-lexer)]
[else default])))

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#lang at-exp racket
(require rackunit)
(require "world.rkt")
(check-equal? (with-output-to-string (λ _ (do-place)))
"You're standing in a meadow. There is a house to the north.\n")
(define-syntax-rule (check-cmd? cmd result)
(check-equal? (with-output-to-string (λ _ (do-verb cmd))) result))
(check-cmd?
"s"
"You're in a desert. There is nothing for miles around.\nThere is a cactus here.\nThere is a key here.\n")
(check-cmd?
"get cactus"
"Ouch!\n")
(check-cmd?
"get key"
"You now have the key.\n")
(check-cmd?
"n"
"You're standing in a meadow. There is a house to the north.\n")
(check-cmd?
"n"
"You are standing in front of a house.\nThere is a door here.\n")
(check-cmd?
"open door"
"The door is now unlocked and open.\n")
(check-cmd?
"enter"
"You're in the house.\nThere is a trophy here.\n")
(check-cmd?
"get trophy"
"You win!\n")

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#lang br/demo/txtadv
===VERBS===
north, n
"go north"
south, s
"go south"
east, e
"go east"
west, w
"go west"
up
"go up"
down
"go down"
in, enter
"enter"
out, leave
"leave"
get _, grab _, take _
"take"
put _, drop _, leave _
"drop"
open _, unlock _
"open"
close _, lock _
"close"
knock _
quit, exit
"quit"
look, show
"look"
inventory
"check inventory"
help
save
load
===EVERYWHERE===
quit
(begin
(printf "Bye!\n")
(exit))
look
(show-current-place)
inventory
(show-inventory)
save
(save-game)
load
(load-game)
help
(show-help)
===THINGS===
---cactus---
get
"Ouch!"
---door---
open
(if (have-thing? key)
(begin
(set-thing-state! door 'open)
"The door is now unlocked and open.")
"The door is locked.")
close
(begin
(set-thing-state! door #f)
"The door is now closed.")
knock
"No one is home."
---key---
get
(if (have-thing? key)
"You already have the key."
(begin
(take-thing! key)
"You now have the key."))
put
(if (have-thing? key)
(begin
(drop-thing! key)
"You have dropped the key.")
"You don't have the key.")
---trophy---
get
(begin
(take-thing! trophy)
"You win!")
===PLACES===
---meadow---
"You're standing in a meadow. There is a house to the north."
[]
north
house-front
south
desert
---house-front---
"You are standing in front of a house."
[door]
in
(if (eq? (thing-state door) 'open)
room
"The door is not open.")
south
meadow
---desert---
"You're in a desert. There is nothing for miles around."
[cactus, key]
north
meadow
south
desert
east
desert
west
desert
---room---
"You're in the house."
[trophy]
out
house-front
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