define and annotate some language elements

1 files changed, 23 insertions, 0 deletions

diff --git a/language/type-definition.rst b/language/type-definition.rst
new file mode 100644
index 0000000..02616b8
--- /dev/null
+++ b/language/type-definition.rst
@@ -0,0 +1,23 @@
+Defining Types
+--------------
+
+.. crowbar:element:: TypeDefinition <- StructDefinition / EnumDefinition / UnionDefinition
+
+    Crowbar has three different kinds of user-defined types.
+
+.. crowbar:element:: StructDefinition <- 'struct' identifier '{' VariableDeclaration+ '}' ';'
+
+    A ``struct`` defines a composite type with several members.
+
+    .. todo::
+
+        define struct layout in memory
+
+.. crowbar:element:: EnumDefinition <- 'enum' identifier '{' EnumMember (',' EnumMember)* ','? '}' ';'
+                     EnumMember <- identifier ('=' Expression)?
+
+    An ``enum`` defines a type which can take one of several specified values.
+
+    .. todo::
+        
+        define enum value assignment, type-related behavior