1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
//! Can You See Me Now?
//!
//! - **Date:** April 26, 2019
//! - **Subject:** Item visibility and `pub(<restricted>)` as API design tools.
//! - [**download mp3**][mp3]
//! - [**script**][script]
//!
//! [mp3]: https://www.podtrac.com/pts/redirect.mp3/cdn.newrustacean.com/file/newrustacean/e030.mp3
//! [script]: https://newrustacean.com/show_notes/e030/struct.script
//!
//! <audio style="width: 100%" title="e030: Can You See Me Now?" controls preload=metadata src="https://www.podtrac.com/pts/redirect.mp3/cdn.newrustacean.com/file/newrustacean/e030.mp3">
//!
//! Show Notes
//! ----------
//!
//! The easiest and most effective way to understand the example in this case
//! will simply be to look directly at [the source code][src]. You *can* read
//! the docs for each of the nested modules, but you'll be doing a *lot* of
//! navigating around for that.
//!
//! [src]: /src/show_notes/e030.rs.html
//!
//! Also, I am using Cargo’s `--document-private-items` flag, so that you can
//! see *all* the items in *all* the modules, even those which are not public,
//! but note that usually you would not see docs for those!
//!
//! ### Links
//!
//! - [the reference on visibility]
//! - [RFC #1422]
//! - [episode source code]
//! - [e020]
//!
//! [the reference on visibility]: https://doc.rust-lang.org/reference/visibility-and-privacy.html
//! [RFC #1422]: https://github.com/rust-lang/rfcs/blob/master/text/1422-pub-restricted.md
//! [episode source code]: https://newrustacean.com/src/show_notes/e030.rs.html
//! [e020]: https://newrustacean.com/show_notes/e020/
//!
//! Sponsors
//! --------
//!
//! Thanks to Manning for sponsoring the show *and* giving all of you a 40%-off
//! discount on their whole store (but especially their [<cite>WebAssembly in
//! Action</cite> MEAP][MEAP]) at [deals.manning.com/new-rustacean][manning]!
//!
//! [manning]: http://bit.ly/2OXnlEb
//! [MEAP]: https://www.manning.com/books/webassembly-in-action
//!
//! ### Patreon Sponsors
//!
//! - Adam Green
//! - Aleksey Pirogov
//! - Alexander Kryvomaz
//! - Alexander Lozada
//! - Alexander Payne
//! - [Andrew Dirksen]
//! - Andrew Thompson
//! - [Anthony Deschamps]
//! - Anthony Scotti
//! - Arlen Haftevani
//! - [Arlo (Hyena)]
//! - Arun Kulshreshtha
//! - [Behnam Esfahbod]
//! - [Benjamin Manns]
//! - Benjamin Wasty
//! - Brandon 'Spanky' Mills
//! - Brian Casiello
//! - Brian Manning
//! - [Brian McCallister]
//! - [Bryan Stitt]
//! - Caryn Finkelman
//! - Cass Costello
//! - Cat Dad
//! - Chap Lovejoy
//! - [Charlie Egan]
//! - Chip
//! - [Chris Palmer]
//! - Christoffer Ceutz
//! - Cristian Paul
//! - Dan Abrams
//! - Daniel
//! - Daniel Bross
//! - [Daniel Collin]
//! - [Daniel Mason]
//! - David Carroll
//! - David Hewson
//! - [Derek Morr]
//! - Dominic Cooney
//! - Doug Reeves
//! - [Douglas Correa]
//! - Edmund Kump
//! - [Eduard Knyshov]
//! - [Embark Studios]
//! - Eugene Bulkin
//! - [Evan Stoll]
//! - [Fabio (decathorpe)]
//! - [Fabio Correa]
//! - [Gaveen Prabhasara]
//! - [Graham Wihlidal]
//! - [Henri Sivonen]
//! - [Ian Jones]
//! - Hoàng Đức Hiếu
//! - [Hugo Josefson]
//! - "Jake ""ferris"" Taylor"
//! - Jako Danar
//! - James Cooper
//! - James Hagans II
//! - [Jason Bowen]
//! - [Jeff May]
//! - [Jendrik Illner]
//! - Jerome Froelich
//! - JockeTF
//! - [Joar Wandborg]
//! - [Johan Andersson]
//! - [John Rudnick]
//! - Jon
//! - Jonah
//! - [Jonathan Knapp]
//! - Jonathan Turner
//! - Joseph Hain
//! - Joseph Mou
//! - Joseph Schrag
//! - [Joe Percy]
//! - Justin Ossevoort
//! - Kai Yao
//! - Kazutaka Mise
//! - Keith Gray
//! - Kilian Rault
//! - Lee Jenkins
//! - Luca Schmid
//! - [Luiz Irber]
//! - Lukas Eller
//! - [Malnormalulo]
//! - [Martin Heuschober]
//! - Masashi Fujita
//! - Matt Rudder
//! - Matthew Brenner
//! - Matthias Ruszala
//! - [Max Jacobson]
//! - Max R.R. Collada
//! - [Messense Lv]
//! - Micael Bergeron
//! - [Michael Mc Donnell]
//! - [Michael Melanson]
//! - Michael Sanders
//! - [Nathan Sculli]
//! - [Nick Coish]
//! - Nick Gideo
//! - [Nick Stevens]
//! - [Nicolas Pochet]
//! - Oladapo Fadeyi
//! - Olaf Leidinger
//! - Oliver Uvman
//! - [Oluseyi Sonaiya]
//! - Ovidiu Curcan
//! - [Pascal]
//! - [Patrick O'Doherty]
//! - Paul Naranja
//! - Paul Osborne
//! - Peter Scholtens
//! - Peter Tillemans
//! - Pierre-Antoine Champin
//! - Ralph Giles
//! - [Ramon Buckland]
//! - Randy MacLeod
//! - Raph Levien
//! - Richard Dallaway
//! - Rob Tsuk
//! - [Robbie Clarken]
//! - Robert Chrzanowski
//! - Romain Chossart
//! - [Ryan Blecher]
//! - [Ryan Osial]
//! - Scott Moeller
//! - [Sebastián Ramírez Magrí]
//! - [Simon Dickson]
//! - Simon G
//! - [Soren Bramer Schmidt]
//! - Steve Jenson
//! - Steven Knight
//! - Steven Murawski
//! - [Stuart Hinson]
//! - Tim Brooks
//! - Tim Süberkrüb
//! - Tom Prince
//! - Toolmaker's Guild
//! - Ty Overby
//! - Tyler Harper
//! - Victor Kruger
//! - Will Greenberg
//! - Zak van der Merwe
//! - Zachary Snyder
//! - [Zach Peters]
//! - Zaki
//!
//! [Andrew Dirksen]: https://github.com/bddap
//! [Anthony Deschamps]: https://github.com/adeschamps
//! [Arlo (Hyena)]: https://asonix.dog/@asonix
//! [Behnam Esfahbod]: https://github.com/behnam
//! [Benjamin Manns]: https://www.benmanns.com/
//! [Brian McCallister]: https://skife.org/
//! [Bryan Stitt]: http://www.stitthappens.com/
//! [Charlie Egan]: https://charlieegan3.com
//! [Chris Palmer]: http://red-oxide.org/
//! [Damien Stanton]: https://github.com/damienstanton
//! [Daniel Collin]: https://twitter.com/daniel_collin
//! [Daniel Mason]: https://github.com/gisleburt
//! [Daniel P. Clark]: https://6ftdan.com/
//! [David W. Allen]: http://GitHub.com/DataRiot
//! [Derek Morr]: https://twitter.com/derekmorr
//! [Douglas Correa]: http://learnrust.io/
//! [Eduard Knyshov]: https://github.com/edvorg
//! [Embark Studios]: https://www.embark-studios.com
//! [Evan Stoll]: https://github.com/evanjs
//! [Gaveen Prabhasara]: https://twitter.com/gaveen
//! [Fabio (decathorpe)]: https://decathorpe.com/
//! [Fabio Correa]: https://linkedin.com/in/feamcor
//! [Graham Wihlidal]: https://wihlidal.com/
//! [Henri Sivonen]: https://hsivonen.fi/
//! [Ian Jones]: https://www.ianmjones.com/
//! [Hugo Josefson]: https://www.hugojosefson.com
//! [Jason Bowen]: https://twitter.com/jwbowen
//! [Jeff May]: https://gitlab.com/jeffmay
//! [Jendrik Illner]: https://www.jendrikillner.com/
//! [Joar Wandborg]: http://github.com/joar
//! [Johan Andersson]: https://www.embark-studios.com
//! [Jonathan Knapp]: https://www.coffeeandcode.com/
//! [Joe Percy]: http://joetdc.com/
//! [John Rudnick]: http://www.cindur.com/
//! [Luiz Irber]: http://luizirber.org/
//! [Malnormalulo]: https://twitter.com/Malnormalulo
//! [Martin Heuschober]: https://github.com/epsilonhalbe
//! [Max Jacobson]: https://twitter.com/maxjacobson
//! [Messense Lv]: https://github.com/messense
//! [Michael Mc Donnell]: https://www.linkedin.com/in/michaelmcdonnell/
//! [Michael Melanson]: https://www.michaelmelanson.net
//! [Nathan Sculli]: http://influential.co/
//! [Nick Coish]: http://github.com/ncoish
//! [Nick Stevens]: https://github.com/nastevens
//! [Nicolas Pochet]: https://github.com/n-pochet
//! [Oluseyi Sonaiya]: http://oluseyi.info/
//! [Pascal]: https://pascalhertleif.de/
//! [Patrick O'Doherty]: https://twitter.com/patrickod
//! [Philipp Keller]: https://twitter.com/hansapla
//! [Ramon Buckland]: http://www.inosion.com
//! [Robbie Clarken]: https://github.com/RobbieClarken/
//! [Ryan Blecher]: http://notryanb.github.io/
//! [Ryan Osial]: https://github.com/osialr
//! [Sebastián Ramírez Magrí]: https://www.twitter.com/sebasmagri
//! [Simon Dickson]: https://www.simonhdickson.com/
//! [Soren Bramer Schmidt]: http://prisma.io/
//! [Stuart Hinson]: http://stuarth.github.io/
//! [Zach Peters]: https://github.com/zpeters
//!
//! (Thanks to the couple people donating who opted out of the reward tier, as
//! well. You know who you are!)
//!
//! ### Become a sponsor
//!
//! - [Patreon](https://www.patreon.com/newrustacean)
//! - [Venmo](https://venmo.com/chriskrycho)
//! - [Dwolla](https://www.dwolla.com/hub/chriskrycho)
//! - [Cash.me](https://cash.me/$chriskrycho)
//! - [Flattr](https://flattr.com/profile/chriskrycho)
//! - [PayPal.me](https://paypal.me/chriskrycho)
//!
//!
//! Contact
//! -------
//!
//! - New Rustacean:
//!     + Twitter: [@newrustacean](https://www.twitter.com/newrustacean)
//!     + Email: [[email protected]](mailto:[email protected])
//! - Chris Krycho
//!     + GitHub: [chriskrycho](https://github.com/chriskrycho)
//!     + Twitter: [@chriskrycho](https://www.twitter.com/chriskrycho)

#[doc(include = "../docs/e030-script.md")]
pub struct Script;

/// One of two internal modules (with `right`) for demonstrating visibility.
pub mod left {
    /// Visible to other items in `left`, including in sub-modules.
    fn local() {}

    /// `pub(crate) mod a` is visible everywhere within the crate that can see
    /// `left`, but hidden from all external callers.
    pub(crate) mod a {
        /// This is visible everywhere in the crate that can see `a`. Open the
        /// source to see all the other items it can interact with!
        pub fn demo() {
            // We can see other items in `left` or `a` regardless of visibility.
            super::local();
            sibling();

            // We can see other items which are marked as visible within `left`.
            crate::e030::left::b::demo();

            // We can see other items which are marked as visible within `e030`,
            // whether direct siblings to us or not.
            crate::e030::left::c::demo();
            super::c::demo();
            crate::e030::right::s::demo();

            // We can see other items which are marked as visible within the
            // crate.
            crate::e030::right::q::demo();

            // This won't compile because `crate::e030::right::r` is not visible
            // here: it is only visible within `crate::e030::right`.
            // crate::e030::right::r::demo();

            // We also cannot see items in `child` unless they are some `pub`
            // variant.
            // super::private_child::only_in_child();

            // But we can
            // super::private_child::also_only_in_child();
        }

        /// `fn sibling` is visible only to other items within `a`.
        fn sibling() {}

        /// `mod child` here is visible to `a`, but not outside `a` -- including
        /// even is siblings.
        mod private_child {
            /// `fn only_in_child` is not visible to anything outside `child`.
            fn only_in_child() {}

            /// `pub fn also_only_in_child` is also hidden to anything outside
            /// `child`.
            pub fn also_only_in_child() {}
        }
    }

    /// `pub(in crate::e030::left) mod b` is visible to
    pub(in crate::e030::left) mod b {

        /// This is visible everywhere in the crate that can see `b`. Open
        /// the source to see how all the other items it can interact with!
        pub fn demo() {}
    }

    pub(in crate::e030) mod c {
        /// This is visible everywhere in the crate that can see `b`. Open the
        /// source to see how all the other items it can interact with!
        pub fn demo() {}
    }
}

/// One of two internal modules (with `left`) for demonstrating visibility.
pub mod right {
    /// This is visible *within* the crate everywhere that can see `right`.
    pub(crate) mod q {
        /// This is visible everywhere in the crate that can see `q`. Visibility
        /// exactly mirrors `crate::e030::left::a::demo`.
        pub fn demo() {}
    }

    /// This is visible everywhere in `right`, including in `q`.
    pub(in crate::e030::right) mod r {
        /// This is visible everywhere in the crate that can see `s`. Open
        /// the source to see how all the other items it can interact with!
        pub fn demo() {}
    }

    /// This is visible everywhere in the e030 module.
    pub(in crate::e030) mod s {
        pub fn demo() {}
    }
}