runtime(doc): further improve docs about List/Blob += operator
closes: #13990
Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 3dbbbea..e3a9f20 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -1,4 +1,4 @@
-*eval.txt* For Vim version 9.1. Last change: 2024 Feb 07
+*eval.txt* For Vim version 9.1. Last change: 2024 Feb 08
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -303,12 +303,15 @@
*list-concatenation*
Two lists can be concatenated with the "+" operator: >
:let longlist = mylist + [5, 6]
-A list can be concatenated with another one in place using the "+=" operator or |extend()|: >
+ :let longlist = [5, 6] + mylist
+To prepend or append an item, turn it into a list by putting [] around it.
+
+A list can be concatenated with another one in-place using |:let+=| or
+|extend()|: >
:let mylist += [7, 8]
:call extend(mylist, [7, 8])
-
-To prepend or append an item, turn the item into a list by putting [] around
-it. To change a list in-place, refer to |list-modification| below.
+<
+See |list-modification| below for more about changing a list in-place.
Sublist ~
@@ -427,8 +430,7 @@
modified. The value must at least have the number of items in the range: >
:let list[3:5] = [3, 4, 5]
-To add items to a List in-place, you can use the += operator
-|list-concatenation|: >
+To add items to a List in-place, you can use |:let+=| (|list-concatenation|): >
:let listA = [1, 2]
:let listA += [3, 4]
<
@@ -760,12 +762,15 @@
Blob concatenation ~
-
+ *blob-concatenation*
Two blobs can be concatenated with the "+" operator: >
:let longblob = myblob + 0z4455
+ :let longblob = 0z4455 + myblob
+<
+A blob can be concatenated with another one in-place using |:let+=|: >
:let myblob += 0z6677
-
-To change a blob in-place see |blob-modification| below.
+<
+See |blob-modification| below for more about changing a blob in-place.
Part of a blob ~
@@ -808,6 +813,18 @@
modified. The value must have the same number of bytes in the range: >
:let blob[3:5] = 0z334455
+To add items to a Blob in-place, you can use |:let+=| (|blob-concatenation|): >
+ :let blobA = 0z1122
+ :let blobA += 0z3344
+<
+When two variables refer to the same Blob, changing one Blob in-place will
+cause the referenced Blob to be changed in-place: >
+ :let blobA = 0z1122
+ :let blobB = blobA
+ :let blobB += 0z3344
+ :echo blobA
+ 0z11223344
+<
You can also use the functions |add()|, |remove()| and |insert()|.
@@ -2824,6 +2841,8 @@
:let {var} ..= {expr1} Like ":let {var} = {var} .. {expr1}".
These fail if {var} was not set yet and when the type
of {var} and {expr1} don't fit the operator.
+ `+=` modifies a |List| or a |Blob| in-place instead of
+ creating a new one.
`.=` is not supported with Vim script version 2 and
later, see |vimscript-version|.
diff --git a/runtime/doc/tags b/runtime/doc/tags
index ebde436..d5ccb99 100644
--- a/runtime/doc/tags
+++ b/runtime/doc/tags
@@ -6124,6 +6124,7 @@
bitwise-function usr_41.txt /*bitwise-function*
bitwise-shift eval.txt /*bitwise-shift*
blob eval.txt /*blob*
+blob-concatenation eval.txt /*blob-concatenation*
blob-functions usr_41.txt /*blob-functions*
blob-identity eval.txt /*blob-identity*
blob-index eval.txt /*blob-index*