WIP

README.md

@@ -10,9 +10,7 @@ specification phase. There is no grammar, parser, compiler, or way to use any
 Ava code. Ava is a way to get ideas out of my head, challenged, and further
 explored.
 
-## Notes
+## Documentation
 
-These notes are not guaranteed to be up to date and represent a large amount of
+Please start with the [Documentation Contents](./docs), which provides links to
-brainstorming and trying/discarding of ideas.
+different iterations of the language.
-
-Please start with the [Table of Contents](./notes/table-of-contents.md)

docs/README.md

@@ -0,0 +1,6 @@
+# Ava Documentation
+
+This documentation is currently organized by revision, where major updates are
+made to the specification.
+
+- [R2](./revision2.md)

docs/revision2.md

@@ -0,0 +1,463 @@
+# Ava R2
+
+This document specifies the second revision of the Ava programming language,
+started 2024-07-18.
+
+## Table of Contents
+
+- [Names](#names)
+- [Reserved Keywords](#reserved-keywords)
+- [Reserved Symbols and Operators](#reserved-symbols-and-operators)
+- [Namespaces](#namespaces)
+- [Imports](#imports)
+- [Definitions](#definitions)
+- [Comments](#comments)
+- [Constants](#constants)
+
+## Names
+
+_Names_ in Ava source code are user-defined strings that provide some form of
+identifier to some component that may be named. All names in Ava follow the same
+rules.
+
+### Name Rules
+
+- Names are UTF-8 strings.
+- Names may **not** be a reserved keyword.
+- Names may **not** be a reserved symbol/operator.
+- Names may **not** include whitespace characters.
+- Names may **not** include `.`
+- Names may **not** include `"`
+- Names may **not** include `'`
+- Names may **not** include `,`
+- Names may **not** include `:`
+- Names may **not** include `\`
+- Names may **not** include `(`
+- Names may **not** include `)`
+- Names may **not** begin with a number.
+- Two definitions may **not** share the same name in scope.
+    - This implies that names may **not** reuse the name of any standard type
+      that is always considered in scope, such as `Int32` or `Boolean`.
+
+### Name Targets
+
+The following items may be named in Ava:
+
+- [Namespaces](#namespaces)
+- [Definitions](#definitions)
+- [Variables](#variables)
+- [Function Arguments](#function-arguments)
+- [Record Fields](#record-fields)
+- [Destructured Fields](#destructured-fields)
+
+### Name Examples
+
+- `foo`
+- `foo-bar`
+- `foo_bar`
+- `<=`
+- `>`
+- `==`
+- `%`
+- `f1`
+- `_foo`
+- `&&`
+- `||`
+
+## Reserved Keywords
+
+### `namespace`
+
+Used to specify the [Namespace](#namespaces) of a file.
+
+### `import`
+
+Used to declare an [Import](#imports) within a file.
+
+### `private`
+
+Used to mark a [Definition](#definitions) as [Private](#private-accessibility).
+
+### `internal`
+
+Used to mark a [Definition](#definitions) as
+[Internal](#internal-accessibility).
+
+### `let`
+
+Declares an immutable [Variable](#variables) binding.
+
+### `mut`
+
+Declares a mutable [Variable](#variables) binding.
+
+### `const`
+
+Declares a [Constant](#constants) definition.
+
+### `given`
+
+Used to define [type constructors](#type-constructors) within the scope of some
+definition.
+
+### `fn`
+
+Indicates a [function](#functions) definition. Each function may or may not be
+implemented.
+
+### `class`
+
+Indicates a [type class](#type-classes) definition.
+
+### `instance`
+
+Indicates the definition of a specific
+[type class instance](#type-class-instances).
+
+### `match`
+
+Keyword that identifies a [match expression](#match-expressions).
+
+### `λ`
+
+Alias for the [case](#case) keyword.
+
+### `case`
+
+Defines a [pattern matching](#pattern-matching) case within some pattern
+matching context (either a function implementation or a match expression).
+
+### `end`
+
+Used to indicate the end of some block.
+
+### `type`
+
+Declare a [type definition](#type-definitions).
+
+### `opaque`
+
+Declare an [opaque type](#opaque-types).
+
+### `record`
+
+Define a [record](#records) (immutable data structure).
+
+### `enum`
+
+Define a new [enumeration](#enumerations) (sum type).
+
+### `as`
+
+Used to rename a specific [import](#imports).
+
+### `if`
+
+Denotes an [if/then/else expression](#if-then-else-expressions).
+
+### `then`
+
+Required after the predicate of an
+[if/then/else expression](#if-then-else-expressions).
+
+### `else`
+
+Required after the first block of an
+[if/then/else expression](#if-then-else-expressions).
+
+### `true`
+
+The Boolean value `true`.
+
+### `false`
+
+The Boolean value `false`.
+
+### `object`
+
+Define a [singleton object](#singleton-objects).
+
+### MISSING SOME VALUES
+
+TODO: Things like `do`/`return`, `infix`, `const`
+
+TODO: Consider `abstract` to be used for abstract type class functions.
+
+## Reserved Symbols and Operators
+
+### `.` (Access Operator)
+### `=` (Assignment Operator)
+### `:` (Type Assignment Operator)
+### `::` (Type Class Membership Operator)
+### `(` (Open Parenthesis)
+### `)` (Close Parenthesis)
+### `,` (Comma)
+### `=>` (Case Implementation Operator)
+### `->` (Type Function Operator)
+### `_` (Anonymous Value Binding)
+### `|` (Type Union Operator)
+### `--` (Comment Prefix)
+
+## Namespaces
+
+The primary organizational concept in Ava is the _namespace_. Namespaces must be
+explicitly declared in _every_ Ava file.
+
+### Rules
+
+- Every Ava source file _must_ begin with a `namespace` declaration.
+- The first non-comment code in any Ava source file _must_ be a `namespace`
+  declaration.
+- Namespaces must contain at least one [name](#names).
+- Namespaces may concatenate names using the `.` character.
+- Multiple files may share the same namespace.
+- Namespaces are **public** by default. This means that if any
+  [definition](#definition) is not marked [private](#definition-accessibility)
+  or [internal](#definition-accessibility), all definitions will be exported.
+
+### Syntax Specification
+
+```
+namespace <name>[.<name>]*
+```
+
+### Syntax Examples
+
+```
+namespace foo
+namespace foo.bar
+namespace foo.bar.baz_buzz
+namespace foo.bar.v0
+```
+
+## Imports
+
+An `import` can be used to pull other namespaces, or [definitions](#definitions)
+from other namespaces, into the current scope.
+
+### Rules
+
+- Imports **must** follow the [namespace](#namespaces) declaration.
+- Imports may **not** be placed after any definition.
+- Glob imports may **not** use `as` to rename (since they have no specific
+  target to rename).
+
+### Syntax Specification
+
+```
+import <name>[.<name>]*[.\* | as <name>]
+```
+
+### Syntax Examples
+
+```
+-- import a namespace, which can be referenced by name
+import foo.bar
+
+-- import everything within some namespace
+import foo.bar.baz.*
+
+-- import a specific definition from within a namespace
+import foo.bar.SomeDef
+
+-- import and rename a namespace
+import baz.buzz as bb
+
+-- import and rename a specific definition from within a namespace
+import baz.buzz.FooBar as Foo
+```
+
+## Definitions
+
+A "definition" is something that might be _defined_ at the top level of any Ava
+source file. These include:
+
+- [Constants](#constants)
+- [Functions](#functions)
+- [Infix Functions](#infix-functions)
+- [Type Classes](#type-classes)
+- [Type Class Instances](#type-class-instances)
+- [Enumerations](#enumerations)
+- [Records](#records)
+- [Type Definitions](#type-definitions)
+- [Opaque Types](#opaque-types)
+
+### Definition Accessibility
+
+All definitions are **public** by default. All definitions **may** be modified
+to be either [internal](#internal-accessibility) or
+[private](#private-accessibility).
+
+### Internal Accessibility
+
+`internal` definitions are only accessible _within their namespace_. This means
+that they are shared across files that share a namespace.
+
+```
+internal fn foo: Int32 -> Int32
+    λ x => x + 1
+end fn
+```
+
+Unused `internal` definitions are considered errors.
+
+### Private Accessibility
+
+`private` definitions are only accessible _within their file_. Even if another
+file shares a namespace, `private` definitions are invisible to that file.
+
+```
+private fn foo: Int32 -> Int32
+    λ x => x + 1
+end fn
+```
+
+Unused `private` definitions are considered errors.
+
+## Comments
+
+_Comments_ are sections of code that are not parsed as code. They are used to
+add in-code documentation.
+
+### Rules
+
+- All comments begin with `--`. This is a _prefix_, `--` tells the parser to
+  ignore any following content on sight.
+- Multi-line comments are **not** supported.
+- Names may _not_ include the comment designator.
+
+### Standard Comment Syntax
+
+Comments start with `--`. If that string is detected, the comment initializer to
+the end of the line will be completely ignored.
+
+### Docstring Comment Syntax
+
+Docstrings start with `---` and must precede a _definition_ at the top level of
+some source file. Docstrings _may_ be parsed in a separate process to produce a
+documentation artifact.
+
+### Examples
+
+```
+--- This is a docstring for the function definition.
+fn foo: String -> String
+    -- This is a regular comment.
+    --- This is a regular comment, because it is not at the definition level.
+    λ x => x + x
+end fn
+```
+
+## Constants
+
+_Constants_ are top-level [definitions](#definitions) in Ava. They are named,
+concrete values with a concrete type.
+
+### Rules
+
+- Constants must be defined at the top level of Ava source files.
+- Constants must have an explicit type (they may not infer).
+- Constants must have a concrete type.
+- Constants must have a literal value.
+- Constants _may_ reference the value of another constant.
+- Constants _may_ be a record, itself defined in terms of literal values or
+  constant values.
+
+Note that these rules exist to permit constant definitions that are not limited
+to literal values.
+
+### Syntax
+
+Constants are defined using the [const](#const) keyword.
+
+```
+const <name>: <type> = <value>
+```
+
+### Examples
+
+```
+const foo: String = "foo"
+const bar: Int32 = 12
+
+record Foo
+    x: String,
+    y: Int32,
+end record
+
+const baz: Foo = Foo(foo, bar)
+```
+
+## Functions
+
+_Functions_ are top-level [definitions](#definitions) in Ava, values in Ava, and
+are the heart of programming in Ava. In general, functions have type `A -> B`,
+where input of type `A` produces a result of type `B`.
+
+### Functions Without Arguments
+
+Technically, there are _no_ functions without arguments in Ava. All functions
+are pure, and thus a function without arguments is just a value. The `Unit` type
+can be used as a "nothing" argument, as it's a singleton object.
+
+```
+given A
+record IO
+    thunk: Unit -> A
+end record
+
+given A
+fn io_new: (Unit -> A) -> IO A
+    λ thunk => IO(thunk = thunk)
+end fn
+
+fn demonstrate: Unit -> IO Int32
+    λ () =>
+        block
+            let foo: Int32 = 10
+            let bar: IO Int32 = io_new λ () => foo
+            bar
+        end block
+end fn
+```
+
+### Functions With Multiple Arguments
+
+Arguments should be chained with `->` in Ava:
+
+```
+import ava.string
+
+fn example: String -> Int32 -> Int32
+    λ x y => (string.length x) + y
+end fn
+```
+
+Technically, this represents a curried function with left associativity:
+
+```
+A -> B -> C -> D == ((A -> B) -> C) -> D
+```
+
+This means that Ava naturally supports curried functions with partial
+application:
+
+```
+fn example: Int32 -> Int32 -> Int32 -> Int32
+    λ x y z => x + y + z
+end fn
+
+let add1: Int32 -> Int32 -> Int32 = example 1
+
+-- Result: 6
+let result = add1 2 3
+```
+
+In this case, `example 1` invokes `example` with an input of literal value `1`,
+which results in a partial application of example that looks like:
+
+```
+fn partial: Int32 -> Int32 -> Int32
+    λ y z => 1 + y + z
+end fn
+```

docs/sketch-atomics-mutation.md

@@ -0,0 +1,63 @@
+# Sketch: Atomics and Mutation
+
+What does it look like to mutate state outside of the scope of a function?
+
+## Problem Statement
+
+I want the ability to _modify_, _in-place_, the value of some reference or some
+value on the stack. I want the ability to do this _outside_ of the scope of a
+single function.
+
+## Example Functionality
+
+What is a `State`? How is a `state_set` implementation possible?
+
+```
+fn example: State String -> String -> IO Unit
+    λ state newValue => state_set state newValue
+end fn
+```
+
+## Problem: Thread-Safe Access
+
+- All access to the `State` "thing" must be thread-safe.
+
+## Problem: Representation
+
+- Ava, to this point, has not had any record-mutable state or the notion of such
+  an object.
+- Ava does not and will not have inheritance (precondition).
+- Must Ava have a mutable primitive?
+- How could Ava support mutability without direct access? This implies that
+  something like `mut` as a `record` field modifier is not sufficient.
+
+## Idea: Support via Modifiers
+
+The following implementation is incomplete and does not enforce any thread
+safety, but illustrates how `private` access could help this work.
+
+Also, it demonstrates that anonymous function syntax needs to be considered.
+
+```
+given A
+record State
+    private mut data: A,
+end record
+
+given A
+fn state_get: State A -> IO A
+    λ state => defer (λ => state.data)
+end fn
+
+given A
+fn state_set: State A -> A -> IO State A
+    λ state newValue => map (defer (λ => state.data = newValue)) (λ => state)
+end fn
+
+given A
+fn state_modify: State A -> (A -> A) -> IO State A
+    λ state f =>
+        map
+            (defer λ => state.data = f state.data)
+            λ => state
+```