X-Git-Url: https://git.lukelau.me/?p=scheme.git;a=blobdiff_plain;f=abi.md;h=c2ff16575c1da283f8c4d9c63a06d24c5ebe96ce;hp=5f09227ae56f2b21e31e7eca856a2e9917f60eec;hb=8e106ca13666680051f91ab3f49ce2bd7e19ead7;hpb=91145e54f41ee88f1e279a80430b3f5ed4e7a8c6

diff --git a/abi.md b/abi.md
index 5f09227..c2ff165 100644
--- a/abi.md
+++ b/abi.md
@@ -4,6 +4,22 @@ a heap is allocated at the start, and the address to the next free
 space on it is stored in `heap_start`. it needs to be
 updated/decremented whenever you put anything on the heap
 
+## todo
+- how should allocation be managed?
+make free blocks a doubly linked list. (how big is a block?)
+when allocating, use first free block, move up free pointer
+when freeing, do ???
+
+
+# ownership
+
+```
+(let ([s "hello"])  <- s should be a linear string
+  (mkpair
+    (lambda () (print s))               <- two references to s?
+    (lambda () (print (reverse s)))))
+```
+
 # closures
 
 * lambda: actual function containing the code
@@ -19,6 +35,19 @@ lambda code  1st        2nd       3rd
 address      captive    captive   captive   ...
 ```
 
+## note on recursive closures
+
+The following example shows a recursive lambda, that results in a
+closure that captures itself.
+```
+(let ([f (closure lambda0 (f))])
+  (f 42))
+```
+When this happens, `codegen-let` will insert `(f . 'self-captive)`
+into the environment when codegen'ing the closure. `codegen-closure`
+will then pick this up, and use it to insert its own heap address into
+its inner environment.
+
 # lambdas
 
 lambdas use the system v amd64 calling convention.