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[elpa] externals/dash 12ed9f6 100/439: Add destructive operations !cons
From: |
Phillip Lord |
Subject: |
[elpa] externals/dash 12ed9f6 100/439: Add destructive operations !cons og !cdr |
Date: |
Tue, 04 Aug 2015 20:26:52 +0000 |
branch: externals/dash
commit 12ed9f6622f66daffeb0c23d5497cd2933333225
Author: Magnar Sveen <address@hidden>
Commit: Magnar Sveen <address@hidden>
Add destructive operations !cons og !cdr
---
README.md | 20 ++++++++++++++++++++
dash.el | 8 ++++++++
examples.el | 8 ++++++++
3 files changed, 36 insertions(+), 0 deletions(-)
diff --git a/README.md b/README.md
index 419955b..1c309e5 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,8 @@ Or you can just dump `dash.el` in your load path somewhere.
* [->](#--x-optional-form-rest-more) `(x &optional form &rest more)`
* [->>](#--x-form-rest-more) `(x form &rest more)`
* [-->](#---x-form-rest-more) `(x form &rest more)`
+* [!cons](#-cons-car-cdr) `(car cdr)`
+* [!cdr](#-cdr-list) `(list)`
There are also anaphoric versions of these functions where that makes sense,
prefixed with two dashes instead of one.
@@ -461,6 +463,24 @@ in in second form, etc.
(--> "def" (concat "abc" it "ghi") upcase) ;; => "ABCDEFGHI"
```
+### !cons `(car cdr)`
+
+Destructive: Sets `cdr` to the cons of `car` and `cdr`.
+
+```cl
+(let (l) (!cons 5 l) l) ;; => '(5)
+(let ((l '(3))) (!cons 5 l) l) ;; => '(5 3)
+```
+
+### !cdr `(list)`
+
+Destructive: Sets `list` to the cdr of `list`.
+
+```cl
+(let ((l '(3))) (!cdr l) l) ;; => '()
+(let ((l '(3 5))) (!cdr l) l) ;; => '(5)
+```
+
## Development
diff --git a/dash.el b/dash.el
index a115338..2756529 100644
--- a/dash.el
+++ b/dash.el
@@ -27,6 +27,14 @@
;;; Code:
+(defmacro !cons (car cdr)
+ "Destructive: Sets CDR to the cons of CAR and CDR."
+ `(setq ,cdr (cons ,car ,cdr)))
+
+(defmacro !cdr (list)
+ "Destructive: Sets LIST to the cdr of LIST."
+ `(setq ,list (cdr ,list)))
+
(defun -map (fn list)
"Returns a new list consisting of the result of applying FN to the items in
LIST."
(mapcar fn list))
diff --git a/examples.el b/examples.el
index 1c8211a..bbe5654 100644
--- a/examples.el
+++ b/examples.el
@@ -189,3 +189,11 @@
(--> "def" (concat "abc" it "ghi")) => "abcdefghi"
(--> "def" (concat "abc" it "ghi") (upcase it)) => "ABCDEFGHI"
(--> "def" (concat "abc" it "ghi") upcase) => "ABCDEFGHI")
+
+(defexamples !cons
+ (let (l) (!cons 5 l) l) => '(5)
+ (let ((l '(3))) (!cons 5 l) l) => '(5 3))
+
+(defexamples !cdr
+ (let ((l '(3))) (!cdr l) l) => '()
+ (let ((l '(3 5))) (!cdr l) l) => '(5))
- [elpa] externals/dash 0e5c69b 089/439: Docs: more concise example for anaphoric functions., (continued)
- [elpa] externals/dash 0e5c69b 089/439: Docs: more concise example for anaphoric functions., Phillip Lord, 2015/08/04
- [elpa] externals/dash f8d74ff 091/439: Docs: update example text to match example code., Phillip Lord, 2015/08/04
- [elpa] externals/dash b0da7b2 093/439: Declare macros before using them., Phillip Lord, 2015/08/04
- [elpa] externals/dash 6931d8a 094/439: Remove Melpa from installation while waiting for it to be included., Phillip Lord, 2015/08/04
- [elpa] externals/dash 0c55a4b 090/439: 1.0.0, Phillip Lord, 2015/08/04
- [elpa] externals/dash 0bd26ac 096/439: Add aliases for -p instead of ?, Phillip Lord, 2015/08/04
- [elpa] externals/dash a2941cd 097/439: Typo, Phillip Lord, 2015/08/04
- [elpa] externals/dash dc6f46c 098/439: Simplify docs-generation using dash., Phillip Lord, 2015/08/04
- [elpa] externals/dash f1c8453 083/439: Rename to dash., Phillip Lord, 2015/08/04
- [elpa] externals/dash eacb6f2 092/439: Docs: Better generation of github urls., Phillip Lord, 2015/08/04
- [elpa] externals/dash 12ed9f6 100/439: Add destructive operations !cons og !cdr,
Phillip Lord <=
- [elpa] externals/dash 79b56cc 101/439: Use --each, !cons and !cdr to simplify implementations., Phillip Lord, 2015/08/04
- [elpa] externals/dash 81a3247 104/439: Let -each and -each-while take multiple forms., Phillip Lord, 2015/08/04
- [elpa] externals/dash ba60707 103/439: Use --each-while to simplify implementations., Phillip Lord, 2015/08/04
- [elpa] externals/dash eb50d17 106/439: Add Melpa back in., Phillip Lord, 2015/08/04
- [elpa] externals/dash 4fedd2e 099/439: Add -partition and -partition-all, Phillip Lord, 2015/08/04
- [elpa] externals/dash 38eed45 095/439: Add rainbow-dash, Phillip Lord, 2015/08/04
- [elpa] externals/dash 49512b9 107/439: Simplify -take and -drop with --dotimes, Phillip Lord, 2015/08/04
- [elpa] externals/dash ed47814 105/439: Add -dotimes, Phillip Lord, 2015/08/04
- [elpa] externals/dash a08fc14 102/439: Add -each-while, Phillip Lord, 2015/08/04
- [elpa] externals/dash c56925a 111/439: Add font-lock for new functions and the `it` token., Phillip Lord, 2015/08/04