Add license and README

LICENSE.md

@@ -0,0 +1,21 @@
+# The MIT License (MIT)
+
+Copyright © 2019 David Moles
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the “Software”),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

README.md

@@ -0,0 +1,68 @@
+# propper
+
+A simplistic implementation of Vladimir Propp’s _Morphology of the Folktale_,
+based on [this exegesis](http://bactra.org/reviews/propp-morphology.html) by
+Cosma Shalizi, to generate a random folktale outline.
+
+## Usage
+
+```sh
+propper [-s seed]
+```
+
+Pass the same seed to repeat generation of the same “tale”.
+
+Example output:
+
+```
+seed: 1572475950978442000
+functions: ABC↑DEFGHJIK↓PrRsoLQExTUW
+```
+
+```
+One member of a family lacks something
+Misfortune or lack is made known; the hero is approached with a request; he is allowed to go
+The seeker agrees to counteraction
+The hero leaves home
+The hero is attacked, which prepares the way for receiving a magical agent
+The hero reacts to the actions of the future donor
+The hero acquires the use of a magical agent
+The hero is led to the whereabouts of an object of search
+The hero and the villain join in direct combat
+The hero is branded or marked
+The villain is defeated
+The initial misfortune or lack is liquidated
+The hero returns
+The hero is pursued
+Rescue of the hero from pursuit
+The hero, unrecognized, in another country
+A false hero presents unfounded claims
+The hero is recognized
+The false hero or villain is exposed
+The hero is given a new appearance
+The villain is punished
+The hero is married and ascends the throne
+```
+
+## Simplifying assumptions
+
+- where Propp presents an implicit choice, e.g. **_C_**, “The seeker agrees to or decides upon counteraction”,
+  this is decomposed into branches of equal probability:
+  1. “The seeker agrees to counteraction” (**_C₁_**)
+  2. “The seeker decides upon counteraction” (**_C₂_**)
+- for the explicit choice between **_A_** “The villain causes harm or injury to a member of a family”
+  and **_a_** “One member of a family either lacks something or desires to have something”, we unpack
+  the implicit choice and assume all branches have equal probability:
+  1. “The villain causes harm or injury to a member of a family” (**_A_**)
+  2. “One member of a family lacks something” (**_a₁_**)
+  3. “One member of a family desires to have something” (**_a₂_**)
+
+## Programmer laziness
+
+Where we make these implicit choices, we don't bother to document which branch was taken
+in the `functions:` output -- e.g. instead of **_A_**, **_a₁_**, and **_a₂_** we always output **_A_**.
+
+## Open questions
+
+- What is the significance of the em dash (**—**) in, e.g., **_ABC↑FH−IK↓LM−NQExUW_**?
+- Where and how should we interpolate Propp's "less essential" functions **_β_** — **_θ_**?