errno stuff and defer words wheeeee

1 files changed, 19 insertions, 1 deletions

diff --git a/readme.md b/readme.md
index 73af8a2..b41ba3a 100644
--- a/readme.md
+++ b/readme.md
@@ -149,7 +149,6 @@ fetch the 64 bit value at memory address a.
 ### `=   ( n1 n2 -- ? )`
 return true if n1 and n2 are equal.
 
-
 ### `<   ( n1 n2 -- ? )`
 return true if n1 is less than n2.
 
@@ -177,6 +176,9 @@ return true if n1 is greater than or equal to n2.
 ### `>body   ( ht -- xt )`
 yield the code field of header token.
 
+### `>defer   ( xt -- a )`
+get the xt storage address of the deferred execution token.
+
 ### `>errno   ( u -- val err )`
 transform the result of a system call into a value/error pair.
 if no error occured, err is zero and val is the result,
@@ -337,6 +339,17 @@ store the 32 bit value u into the memory address a.
 ### `decimal ( -- )`
 set current base to decimal.
 
+### `defer   ( "name" -- )`
+create a new word, the behaviour of which can be controlled with
+`defer!`, `defer@`, `is` and `action-of`.
+initially it is set to yield an error.
+
+### `defer!   ( xt1 xt2 -- )`
+set the deferred word xt2's behaviour to xt1.
+
+### `defer@   ( xt -- xt' )`
+retrieve the xt' which the deferred word xt is set to execute.
+
 ### `does>   ( -- )`
 modify the behaviour of the most recent `create`d word.
 (non-`create`d words will be corrupted.)
@@ -426,6 +439,9 @@ until it runs out.
 ### `invert   ( u -- u' )`
 invert all bytes in u.
 
+### `is   ( xt "name" -- ) IMMEDIATE`
+set the deferred word name to execute xt.
+
 ### `latest   ( -- a )`
 a variable containing the execution token of
 the most recently created word.
@@ -707,3 +723,5 @@ but it diverges in a few notable places:
 - PNO words (`<# # #>` etc.) work with single cell numbers.
     this is because this forth has no double number support.
     (128 bit integer arithmetic does not seem all that useful to me)
+- the dynamic allocation `free` word requires a length.
+    this is because munmap requires a length.