Value -> Value/Event/IO-Stream

Close 12

1 files changed, 79 insertions, 0 deletions

diff --git a/core/stream/base.moon b/core/stream/base.moon
new file mode 100644
index 0000000..ee4ee17
--- /dev/null
+++ b/core/stream/base.moon
@@ -0,0 +1,79 @@
+----
+-- base Stream interface.
+--
+-- implemented by `ValueStream`, `EventStream`, and `IOStream`.
+--
+-- @classmod Stream
+
+class Stream
+--- Stream interface.
+--
+-- Methods that have to be implemented by `Stream` implementations
+-- (`ValueStream`, `EventStream`, `IOStream`).
+--
+-- @section interface
+
+  --- return whether this Stream was changed in the current tick.
+  --
+  -- @function dirty
+  -- @treturn boolean
+
+  --- create a mutable copy of this Stream.
+  --
+  -- Used to insulate eval-cycles from each other.
+  --
+  -- @function fork
+  -- @treturn Stream
+
+  --- the type name of this Stream's value.
+  --
+  -- the following builtin typenames are used:
+  --
+  -- - `str` - strings, `value` is a Lua string
+  -- - `sym` - symbols, `value` is a Lua string
+  -- - `num` - numbers, `value` is a Lua number
+  -- - `bool` - booleans, `value` is a Lua boolean
+  -- - `bang` - trigger signals, `value` is a Lua boolean
+  -- - `opdef` - `value` is an `Op` subclass
+  -- - `builtin` - `value` is an `Action` subclass
+  -- - `fndef` - `value` is a `FnDef` instance
+  -- - `scope` - `value` is a `Scope` instance
+  --
+  -- @tfield string type
+
+  --- documentation metadata.
+  --
+  -- an optional table containing metadata for error messages and
+  -- documentation. The following keys are recognized:
+  --
+  -- - `name`: optional name
+  -- - `summary`: single-line description (markdown)
+  -- - `examples`: optional list of single-line code examples
+  -- - `description`: optional full-text description (markdown)
+  --
+  -- @tfield ?table meta
+
+  __tostring: =>
+    value = if @meta.name
+      @meta.name
+    else if 'table' == (type @value) and rawget @value, '__base'
+      @value.__name
+    else
+      tostring @value
+    "<#{@@__name} #{@type}: #{value}>"
+
+  __inherited: (cls) => cls.__base.__tostring = @__tostring
+
+--- static functions
+-- @section static
+
+  --- construct a new Stream.
+  --
+  -- @classmethod
+  -- @tparam string type the type name
+  -- @tparam ?table meta the `meta` table
+  new: (@type, @meta={}) =>
+
+{
+  :Stream
+}