#lang racket/base
;; For legal info, see file "info.rkt".

(require "main.rkt")

(doc (require scriblib/footnote))

(doc (section "Introduction")

     (para (italic "Note: This is an alpha-quality release of the McFly runtime
package, since some other packages the author wants to release depend on this
one.  This alpha release will also help detect any integration problems with
making PLaneT packages dependent on this runtime.  The McFly Tools development
package, which helps a developer author packages using this runtime, might not
yet be available at the time you read this."))

     (para "McFly began as a way for developers of reusable Racket packages to
embed API documentation in the source code of the package.  One documentation
convenience is that McFly can reuse some information from the code in the
documentation, such as optionally getting procedure type informaion from some
contracts, and argument names from "
           (racket lambda)
           " forms.")

     (para "McFly itself is actually implemented in two separate PLaneT packages: this package, "
           (bold "mcfly")
           ", on which packages that use McFly depend; and "
           (hyperlink "" "McFly Tools")
           ", which provides "
           (tt "raco")
           "-based tools to help develop packages that use McFly, including things
not strictly documentation-related, such as maintaining PLaneT development
links based on information that is also used for documentation.")

     (para "A package that uses McFly will typically include lots of "
           (racket (doc ...))
           " forms sprinkled throughout at least one of its Racket source code files. "
           (note "McFly is so-named due to users of McFly "
                 (hyperlink ""
                            "saying ``doc'' all the time")
           " The package will also generally have a few McFly-specific variables
added to its top "
           (tt "info.rkt")
           " file."))

(doc (subsection "Example")

     (para "The example file "
           (filepath "main.rkt")
           " below shows a use of McFly.")



       (UNSYNTAX (code "#lang racket/base"))

       (require racket/contract
                (planet neil/mcfly))

       (provide/contract (celsius->fahrenheit (-> number? number?))
                         (fahrenheit->celsius (-> number? number?)))

       (doc (section "Introduction")

            (para "This package provides procedures for temperature conversion. The Wikipedia entries for "
                  (hyperlink ""
                  " and "
                  (hyperlink ""
                  " were used as authoritative references."))

       (doc (section "Interface"))

       (doc procedure celsius->fahrenheit
            "Returns Celsius temperature "
            (racket c-degrees)
            " as Fahrenheit.  For example:"
            (racketinput (celsius->fahrenheit 0)
                         #,(racketresult 32))
            "Celsius is named after the Swedish astronomer Anders Celsius.  Sweden is historically part of the Vodka Belt, with high consumption of distilled beverages, and binge drinking.  That is not to imply anything about validity of Swedish temperature units (cough, cough); just sayin'...")

       (define (celsius->fahrenheit c-degrees)
         (+ (* c-degrees 9/5) 32))

       (doc procedure fahrenheit->celsius
            "Returns Fahrenheit temperature "
            (racket f-degrees)
            " as Celsius.  ``Fahrenheit'' starts with `F'.  You know what else starts with `F'? "
            (italic "Freedom")
            ".  That's right: "
            (italic "America!  Freedom!  Freedom is the only way!"))

       (define (fahrenheit->celsius f-degrees)
         (* (- f-degrees 32) 5/9))

       (doc history

            (#:planet 1:1 #:date "2000-01-02"

                      "Fixes Y2K bug.")

            (#:planet 1:0 #:date "1997-08-29"

                      "Initial version. Judgment Day by Skynet."))))

     (para "When Scribble formats the documentation for the package of which this "
           (filepath "main.rkt")
           " is a part, the McFly runtime generates Scribble syntax from the "
           (racket doc)
           " forms in "
           (filepath "main.rkt")
           " and from metadata information in the corresponding "
           (filepath "info.rkt")
           " file.  This constitutes a complete formatted manual for the
package.  The package author does not typically edit a "
           (filepath "*.scrbl")
           " file."
           "  (McFly Tools generates a small "
           (filepath "doc.scrbl")
           " file that merely calls the McFly runtime to process "
           (filepath "main.rkt")
           " whenever Scribble goes to format the documentation.  McFly Tools includes this generated "
           (filepath "doc.scrbl")
           " file when making the "
           (filepath "*.plt")
           " archive for upload to the PLaneT server.)")

     (para "Note that the "
           (racket doc)
           " forms in "
           (filepath "main.rkt")
           " do not affect its normal compilation, and effectively are treated as comments.  This is because "
           (racket (require (planet neil/mcfly)))
           " imports a dummy "
           (racket doc)
           " syntax that merely transforms to an empty "
           (racket begin)
           " form."))

(doc (section "Interface")

     (para "The language of McFly is the "
           (racket doc)
           " form, as interpreted by the McFly runtime when formatting documentation."))

(doc (defform*/subs #:id doc
       #:literals (history procedure scribble)
       ((doc procedure id pre-flow ...)
        (doc history   history-entry ...)
        (doc scribble  pre-flow ...)
        (doc           pre-flow ...))
       ((history-entry (maybe-version planet date pre-flow ...))
        (maybe-version code:blank
                       (code:line #:version string))
        (planet        (code:line #:planet  number-colon-number-symbol))
        (date          (code:line #:date    yyyy-mm-dd-string)))

       "Someday, this will be documented, but it's pretty self-explanatory."))

(doc (section "Known Issues")

     "This alpha version of the McFly runtime has a number of known
issues (partly due to heavy reworking, on-and-off, as we learned more about
syntax objects and made some big design changes, without code cleanup) that we
have not yet gotten around to looking into:"


      (item "Scribble is not linking identifiers.  First assumption is that
some information used by Scribble, perhaps lexical context from the syntax
objects, is not preserved.")
      (item "There is a kludge involving "
            (racket mcfly:para-if-pre-content)
            " that we'd like to get rid of.")

      (item "The ability to infer information for turning "
            (racket (doc procedure ...))
            " to "
            (racket defproc)
            " syntax is limited.  Presently, McFly recognizes only a few forms,
such as "
            (racket define)
            (racket lambda)
            " and "
            (racket provide/contract)
            ".  "
            (racket lambda)
            " is handled pretty well.  The only procedure contract combinator
handled at the moment is "
            (racket ->)
            ".  The current internal representation and unification can support
some other things with few changes, but we have not yet gotten to it.")

      (item "It could use better testing.")))

(doc history

     (#:planet 1:0 #:date "2012-06-11"

               "First alpha release.  Not for general use."))

;; TODO: We might want to intercept errors on user-supplied expressions, to at
;; least give location info.  For example, "(italic not)" in "soundex.rkt"
;; resulted in:
;; (cd /home/user/racket/soundex && scribble soundex.scrbl)
;; italic: contract violation, expected <pre-content?>, given: #<procedure:not>
;;   contract from <collects>/scribble/base.rkt, blaming
;;     /home/user/racket/soundex/soundex.scrbl
;;   contract:
;;     (->* () #:rest (listof pre-content?) element?)
;;   at: <collects>/scribble/base.rkt:293.2
;;  === context ===
;; /usr/local/racket-5.1.2/lib/racket/collects/racket/contract/private/blame.rkt:58:0: raise-blame-error
;; /usr/local/racket-5.1.2/lib/racket/collects/racket/private/map.rkt:45:11: for-each
;; /usr/local/racket-5.1.2/lib/racket/collects/racket/contract/private/misc.rkt:565:14
;; /usr/local/racket-5.1.2/lib/racket/collects/racket/contract/private/prop.rkt:180:10
;; /usr/local/racket-5.1.2/lib/racket/collects/scribble/private/manual-proc.rkt:137:0: *defproc
;; /home/user/racket/soundex/soundex.scrbl: [running body]
;; /usr/local/racket-5.1.2/lib/racket/collects/racket/private/map.rkt:18:11: map
;; /usr/local/racket-5.1.2/lib/racket/collects/scribble/run.rkt: [running body]

;; TODO: Add "doc include".  Use "racket/include" for this?

;; TODO: Add "doc form" and "doc forms" (or "syntax" instead of "form").

;; TODO: Add "doc parameter"?

;; TODO: Add "doc struct". Different forms for "stuct" vs. "define-struct"?

;; TODO: Also save information from "provide"-like forms that rename the
;; identifiers.

;; TODO: Maybe don't keep the hash across file boundaries For each file, after
;; reading, do a pass and update the "doc procedure", "doc Syntax", and others.
;; See how the lexical context or whatever that Scribble seems to need works
;; out first.