Add hugo-easy-gallery (rev 2935729), try one post with it

drafts/2017-04-20-modularity.org

@@ -10,12 +10,12 @@ _Modularity_ and _abstraction_ feature prominently wherever computers
 are involved.  This is meant very broadly: it applies to designing
 software, using software, integrating software, and to a lot of
 hardware as well.  It applies elsewhere, and almost certainly
-originated there first, however, it appears to be particularly
-crucial around software.
+originated there first, however, it appears especially crucial around
+software.
 
 Definitions, though, are a bit vague (including anything in this
 post).  My goal in this post isn't to try to (re)define them, but to
-explain a bit of their essence, and expand on a few theses:
+explain their essence and expand on a few theses:
 
 - Modularity arises naturally in a wide array of places.
 - Modularity and abstraction are intrinsically connected.
@@ -60,9 +60,10 @@ different from being vague.  The purpose of abstraction is not to be
 vague, but to create a new semantic level in which one can be
 absolutely precise."  Joel Spolsky, in one of few instances of me
 actually caring what he said, also has a blog post from 2002 on the
-[[https://www.joelonsoftware.com/2002/11/11/the-law-of-leaky-abstractions/][Law of Leaky Abstractions]].  The [[https://en.wikipedia.org/wiki/Principle_of_least_privilege][principle of least privilege]] is
-likewise a thing. So, abstraction too has its practical and
-theoretical limitations.
+[[https://www.joelonsoftware.com/2002/11/11/the-law-of-leaky-abstractions/][Law of Leaky Abstractions]] ("All non-trivial abstractions, to some
+degree, are leaky.")  The [[https://en.wikipedia.org/wiki/Principle_of_least_privilege][principle of least privilege]] is likewise a
+thing. So, abstraction too has its practical and theoretical
+limitations.
 
 * How They Relate
 
@@ -112,15 +113,15 @@ some details implies that a module is handling those details, that the
 details shouldn't matter, and what does matter is the abstraction one
 is using.
 
-# -----
-Consider the information this module deals in, in essence.
+One of Rich Hickey's favorite topics is *composition*, and with good
+reason (and you should check out [[http://www.infoq.com/presentations/Simple-Made-Easy/][Simple Made Easy]] regardless).  This
+relates as well: to *compose* things together effectively into bigger
+parts requires that they support some common abstraction.
+
+In the same area, [[https://clojurefun.wordpress.com/2012/08/17/composition-over-convention/][Composition over convention]] is a good read on how
+/frameworks/ run counter to modularity: they aren't built to behave
+like modules of a larger system.
 
-What is the most general form this information could be expressed in,
-without being so general as to encompass other things that are
-irrelevant or so low-level as to needlessly constrain the possible
-contexts?
- 
-(Aristotle's theory of definitions?)
 
 # -----
 
@@ -152,6 +153,33 @@ contains fewer incidental details, and more essential details.
 
 # -------
 
+* Information
+
+I referred earlier to the abstractions themselves as both boundaries
+and communications channels.  Another common view is that abstractions
+are *contracts* with a communicated and agreed purpose, and I think
+this is a useful definition too: it conveys the notion that there are
+multiple parties involved and that they are free to behave as needed
+provided that they fulfill some obligation
+
+Some definitions refer directly to information, like the [[https://en.wikipedia.org/wiki/Abstraction_principle_(computer_programming)][abstraction
+principle]] which aims to reduce duplication of information which fits
+with [[https://en.wikipedia.org/wiki/Don%2527t_repeat_yourself][don't repeat yourself]] so that "a modification of any single
+element of a system does not require a change in other logically
+unrelated elements".
+
+
+
+# ----- FIXME
+Consider the information this module deals in, in essence.
+
+What is the most general form this information could be expressed in,
+without being so general as to encompass other things that are
+irrelevant or so low-level as to needlessly constrain the possible
+contexts?
+ 
+(Aristotle's theory of definitions?)
+
 * Less-Conventional Examples
 
 One thing I've watched with some interest is when new abstractions
@@ -256,9 +284,6 @@ machine learning conflicts with proper modularity and abstraction.
 a good post and shows some sorts of abstraction that still exist
 at least in neural networks.)
 
-[[https://clojurefun.wordpress.com/2012/08/17/composition-over-convention/][Composition over convention]] is an important read on why /frameworks/
-can also run completely counter to modularity.
-
 Submitted without further comment:
 https://github.com/stevemao/left-pad/issues/4
 
@@ -307,11 +332,6 @@ https://github.com/stevemao/left-pad/issues/4
 
 - https://twitter.com/fchollet/status/962074070513631232
 
-- How does this fit with /composition/? Does it?
-  - The ability to sensibly compose things depends on them having some
-    sort of well-defined, compatible boundary - right?
-  - Note also /decomposition/ here, as in /decomposing/ something into
-    parts.
 - [[https://mitpress.mit.edu/sites/default/files/sicp/full-text/book/book-Z-H-9.html#%25_chap_1][From SICP chapter 1 intro]]: "The acts of the mind, wherein it exerts
   its power over simple ideas, are chiefly these three: 1. Combining
   several simple ideas into one compound one, and thus all complex
@@ -338,14 +358,11 @@ https://github.com/stevemao/left-pad/issues/4
   boundaries, the abstractions that it interfaces with or that it
   implements) so that the 'inside' can change more or less freely
   without having any effect on the outside.
-- Abstractions as _contracts_ with a communicated/agreed purpose
 - Abstractions as a way of reducing the work required to add
   functionality (changes can be made just in the relevant modules, and
   other modules do not need to change to conform)
 - What is more key?  Communication, information content, contracts,
   details?
-- [[https://en.wikipedia.org/wiki/Abstraction_principle_(computer_programming)][Abstraction principle]]
-  - Reduce duplication of information
   - [[https://en.wikipedia.org/wiki/Don%2527t_repeat_yourself][Don't repeat yourself]]
 - [[https://simplyphilosophy.org/study/aristotles-definitions/][Aristotle & theory of definitions]]
   - this isn't right.  I need to find the quote in the Durant book