From acc36b195914887ed64799c203512c38d9f2a82f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Hru=C5=A1ka?= <ondra@ondrovo.com>
Date: Sat, 10 Oct 2020 18:56:35 +0200
Subject: [PATCH] document the eof, empty and full flags

---
 README.md | 49 ++++++++++++++++++++++++++++++-------------------
 1 file changed, 30 insertions(+), 19 deletions(-)

diff --git a/README.md b/README.md
index 7bf9d54..2b4163a 100644
--- a/README.md
+++ b/README.md
@@ -62,30 +62,39 @@ Arithmetic and other operations set status flags that can be used for conditiona
 - Negative … Value is negative
 - Overflow … Arithmetic overflow or underflow, buffer underflow, etc.
 - Invalid … Invalid arguments for an instruction
-- Carry … Arithmetic carry *this is currently unused*
+- Carry … Arithmetic carry; used by extensions (currently unused, planned for the byte/halfword/word versions of the arith module)
+- Full … full condition; used by extensions
+- Empty … empty condition; used by extensions
+- EOF … end of a stream, file, etc; used by extensions
 
 ### Status tests (conditions)
 
 These keywords (among others) are used in conditional branches to specify flag tests:
 
-- `eq` … Equal,
-- `ne` … NotEqual,
-- `z` … Zero,
-- `nz` … NotZero,
-- `lt` … Lower,
-- `le` … LowerOrEqual,
-- `gt` … Greater,
-- `ge` … GreaterOrEqual,
-- `pos` … Positive,
-- `neg` … Negative,
-- `npos` … NonPositive,
-- `nneg` … NonNegative,
-- `c` … Carry,
-- `nc` … NotCarry,
-- `val`, `valid`, `ok` … Valid,
-- `inval`, `nok` … Invalid,
-- `ov` … Overflow,
-- `nov` … NotOverflow,
+- `eq` … Equal
+- `ne` … NotEqual
+- `z` … Zero
+- `nz` … NotZero
+- `lt` … Lower
+- `le` … LowerOrEqual
+- `gt` … Greater
+- `ge` … GreaterOrEqual
+- `pos` … Positive
+- `neg` … Negative
+- `npos` … NonPositive
+- `nneg` … NonNegative
+- `c` … Carry
+- `nc` … NotCarry
+- `val`, `valid`, `ok` … Valid
+- `inval`, `nok` … Invalid
+- `ov` … Overflow
+- `nov` … NotOverflow
+- `f`, `full` … Full
+- `nf`, `nfull` … Not full
+- `em`, `empty` … Empty
+- `nem`, `nempty` … Not empty
+- `eof` … EOF
+- `neof` … Not EOF
 
 # Syntax
 
@@ -561,6 +570,8 @@ such as animations.
 - They operate over unicode code points, which are a superset of ASCII.
 - The "_r" variants work with raw bytes. Do not combine them, or you may get problems with multi-byte characters.
 
+End of stream is reported by the 'eof' status flag when a stream is read or written.
+
 You can use these special handles in almost all instructions:
 
 ```lisp