Flesh out README.

README.md

@@ -2,14 +2,69 @@
 
 A JavaScript interpreter written in Rust.
 
-A senior design project by Terry Sun and Saghm Rossi, in collaboration with
-David Mally and Professor Steve Zdancewic. Currently very in-progress.
+2015-2016 senior design project by Terry Sun and Saghm Rossi, in collaboration
+with David Mally (for his Master's Thesis) and Professor Steve Zdancewic.
+
+Our [poster] and [report] are included in PDF form under `report/` for
+convenience.
+
+  [poster]: https://github.com/rustoscript/js.rs/blob/master/report/poster.pdf
+  [report]: https://github.com/rustoscript/js.rs/blob/master/report/report.pdf
 
 ## Structure
 
-The parser and AST are currently defined in a secondary package at
-[rustoscript/js.rs-parser][parser]. We are using [lalrpop][lalrpop] as our parser
-generator.
+The parser is currently defined in a secondary package at
+[rustoscript/js.rs-parser][parser], and the AST is defined at
+[rustoscript/js.rs-common][common]. The garbage collection engine is implemented
+by David Mally at [rustoscript/french-press][french-press].
 
-  [parser]: https://github.com/saghm/jsrs-parser
+  [parser]: https://github.com/rustoscript/js.rs-parser
+  [common]: https://github.com/rustoscript/js.rs-common
+  [french-press]: https://github.com/rustoscript/french-press
   [lalrpop]: https://github.com/nikomatsakis/lalrpop
+
+## Instructions
+
+Build and run with Cargo. By default, this opens a REPL.
+
+```bash
+cargo build
+cargo run
+```
+
+You can pass in a JS file to evaluate code from a file.
+
+```bash
+cargo run <file>
+```
+
+Run the Sputnik test suite:
+
+```bash
+cargo run -- --test
+```
+
+## Evaluation
+
+Js.rs was tested using Google's Sputnik, an ECMAScript 5 conformance test suite.
+Sputnik defines several categories of tests, each with various depths of
+subcategories (e.g., the "Expressions" category looks like this:
+
+```
+11_Expressions/
+├── 11.3_PostfixExpressions
+│   ├── 11.3.1_Postfix_Increment_Operator
+│   │   ├── S11.3.1_A1.1_T1.js (a single test)
+│   │   ├── S11.3.1_A1.1_T2.js
+│   │   ├── ...
+```
+
+Overall, there are 111 leaf categories (categories which do not contain other
+categories). We considered the number of leaf categories in which we had passed
+at least one test. Of the 111 categories, we had coverage in 73 of the
+categories, or 65.8%. This indicates that we covered a sizable portion of the
+language's features. This metric represents the breadth of JavaScript that out
+interpreter can handle.
+
+Sputnik provides a total of 2427 distinct tests. Js.rs passes 18.2% of those
+tests.