xo-jit: doc: + glossary entries

docs/glossary.rst

@@ -4,6 +4,49 @@ Glossary
 --------
 
 .. glossary::
+    c.foo
+      | llvm typename for automatically-generated closure type for a lambda
+      | with name `foo`.
+
+    e.foo
+      | llvm typename for automatically-generated local environment for a
+      | lambda with name `foo`.
+
+    w.foo
+      | llvm typename for automatically-generated wrapper function for a
+      | primitive function `foo`.  The wrapper function accepts and ignores
+      | an extra initial argument supplying an environment pointer.
+      |
+      | We apply this practice so that lambdas and primitives support the
+      | same ABI,  so that we can support pointers to abstract functions
+      | that might at runtime turn out to be either primitives or lambdas
+
+    lambda
+      | Common use is for lambda to refer to an anonymous function.
+      | In llvm we need all functions to be named, and those names
+      | have to be unique.
+      |
+      | Since all functions have to be named, we cheerfully adopt
+      | the oxymoron 'named lambda'
+      |
+      | Practices:
+      | 1. Automatically generate unique names for anonymous lambdas.
+      | 2. Incorporate user-provided names for convenience, when provided.
+      | 3. Still have to uniqueify names for user-provided nested lambdas.
+
+    localenv
+      | Shorthand for local environment.
+      | Represents an explicit runtime repsentation for a struct that
+      | holds captured function arguments with the ability to be persisted
+      | (for example, moved to the the heap).
+      |
+      | Note that library `xo-expression` also uses the term environment, but differently.
+      | In that context describes all function arguments.
+
+    lvtype
+      | Shorthand for `llvm::Type`:
+      | llvm-owned representation for a datatype
+
     xsession
       | Shorthand for `llvm::orc::ExecutionSession`.
       | Manages running JIT-generated machine code in the host process