Add 0.2.0 release notes + markdown lints

RELEASES.md

@@ -1,3 +1,50 @@
+Version 0.2  (2022-07-XX)
+=========================
+
+Various bug fixes, language and tooling improvements.
+
+Breaking changes
+----------------
+
+- Using a contract as part of a static type annotations will in most cases fail
+  with an appropriate error message. This is a temporary limitation in order to
+  fix previously unsound behavior in the typechecker. This will likely be fixed
+  in the upcoming 0.3.x release. For more details, see issues
+  [#701](https://github.com/tweag/nickel/issues/701) and
+  [#724](https://github.com/tweag/nickel/issues/724)
+
+Fixes
+-----
+
+- Fix unnecessarily restricted record contract for `record.update`
+- Fix wrong interpretation of long interpolation-like sequences `%..%{` in strings
+- Fix panic when evaluating a `switch` in specific cases
+- Fix fields without definition being assigned to `null`, instead of just being
+  marked as undefined
+
+Language features
+-----------------
+
+- Merge null values together give null, and merging empty lists together gives
+  an empty list, instead of failing with a `error: non mergeable terms`
+- Add recursive let-bindings (`let rec`)
+- Add type wildcard. Use `_` in place of a type to let the typechecker fill
+  the gap. Example: `let foo : _ = array.all ((==) 2) [1,2,3]`
+- Add `builtin.to_str` and `string.from` to convert generic values to a string
+
+Tooling
+-------
+
+- Add the `nickel pprint-ast` command to pretty print a parsed program (for
+  debugging purpose)
+- Add the `nickel doc` command to produce markdown documentation from the
+  in-code `doc` metadata
+
+Documentation
+-------------
+
+- Fix various typos and use of deprecated syntax in the user manual
+
 Version 0.1  (2022-03-10)
 =========================
 
@@ -6,46 +53,46 @@ First release! The main focus has been the design of the Nickel language itself.
 Language features
 -----------------
 
-   * Gradual type system with row types, polymorphism and type inference
-   * Contract system for data validation
-   * Merge system for recursive records that supports one level of overriding
-   * Metadata annotations (default values, documentation, etc.)
-   * Unified syntax for terms, types and contracts (RFC002)
-   * Record destructuring
- 
+- Gradual type system with row types, polymorphism and type inference
+- Contract system for data validation
+- Merge system for recursive records that supports one level of overriding
+- Metadata annotations (default values, documentation, etc.)
+- Unified syntax for terms, types and contracts (RFC002)
+- Record destructuring
+
 Tooling
 -------
 
-   * The main binary supports the following subcommands:
-      * `nickel query` to show metadata and documentation of library functions,
-        the field of a configuration, etc.
-      * `nickel export` to serialize to JSON, YAML, or TOML
-      * `nickel repl` to launch an REPL
-      * `nickel typecheck` to do typechecking without evaluating
+- The main binary supports the following subcommands:
+  - `nickel query` to show metadata and documentation of library functions,
+     the field of a configuration, etc.
+  - `nickel export` to serialize to JSON, YAML, or TOML
+  - `nickel repl` to launch an REPL
+  - `nickel typecheck` to do typechecking without evaluating
 
-   * An LSP-server is included
+- An LSP-server is included
 
 Documentation
 -------------
 
-   * User manual sections on syntax, correctness (types and contracts), and
-     merging
-   * The standard library has been documented in-code (use
-     `nickel query`/`:query` to retrieve it) 
+- User manual sections on syntax, correctness (types and contracts), and
+  merging
+- The standard library has been documented in-code (use
+     `nickel query`/`:query` to retrieve it)
 
 Known limitations
 -----------------
 
-   * The roadmap for overriding and the merge system (RFC001) has not been
-     implemented fully yet.
+- The roadmap for overriding and the merge system (RFC001) has not been
+  implemented fully yet.
 
-   * Performance has not been prioritized.
+- Performance has not been prioritized.
 
-   * Due to the use of reference counting as a memory management strategy,
-     mutually recursive record fields are currently leaking memory. This
-     shouldn't be an issue in a standard workflow.
+- Due to the use of reference counting as a memory management strategy,
+  mutually recursive record fields are currently leaking memory. This
+  shouldn't be an issue in a standard workflow.
 
-   * Standard library APIs and language features are subject to change. There
-     is no backward compatibility guarantees for this version. In general, this
-     release is meant for experimenting and getting user feedback, but isn't
-     intended to be used in production.
+- Standard library APIs and language features are subject to change. There
+  is no backward compatibility guarantees for this version. In general, this
+  release is meant for experimenting and getting user feedback, but isn't
+  intended to be used in production.