[elpa] externals/dash b44140a 288/426: Add -is-prefix/suffix/infix-p

[Phillip Lord]

branch: externals/dash
commit b44140accde3cd6815558288a351190ee7c5ba6f
Author: Matus Goljer <address@hidden>
Commit: Matus Goljer <address@hidden>

    Add -is-prefix/suffix/infix-p
---
 README.md       |   35 +++++++++++++++++++++++++++++++++++
 dash.el         |   30 ++++++++++++++++++++++++++++++
 dev/examples.el |   21 ++++++++++++++++++++-
 3 files changed, 85 insertions(+), 1 deletions(-)

diff --git a/README.md b/README.md
index f52d46d..546c867 100644
--- a/README.md
+++ b/README.md
@@ -80,6 +80,9 @@ Include this in your emacs settings to get syntax 
highlighting:
 * [-only-some?](#-only-some-pred-list) `(pred list)`
 * [-contains?](#-contains-list-element) `(list element)`
 * [-same-items?](#-same-items-list-list2) `(list list2)`
+* [-is-prefix-p](#-is-prefix-p-prefix-list) `(prefix list)`
+* [-is-suffix-p](#-is-suffix-p-suffix-list) `(suffix list)`
+* [-is-infix-p](#-is-infix-p-infix-list) `(infix list)`
 
 ### Partitioning
 
@@ -635,6 +638,38 @@ The order of the elements in the lists does not matter.
 (-same-items? '(1 2 3) '(1 2 3 4)) ;; => nil
 ```
 
+#### -is-prefix-p `(prefix list)`
+
+Return non-nil if `prefix` is prefix of `list`.
+
+```cl
+(-is-prefix-p '(1 2 3) '(1 2 3 4 5)) ;; => t
+(-is-prefix-p '(1 2 3 4 5) '(1 2 3)) ;; => nil
+(-is-prefix-p '(1 3) '(1 2 3 4 5)) ;; => nil
+```
+
+#### -is-suffix-p `(suffix list)`
+
+Return non-nil if `suffix` is suffix of `list`.
+
+```cl
+(-is-suffix-p '(3 4 5) '(1 2 3 4 5)) ;; => t
+(-is-suffix-p '(1 2 3 4 5) '(3 4 5)) ;; => nil
+(-is-suffix-p '(3 5) '(1 2 3 4 5)) ;; => nil
+```
+
+#### -is-infix-p `(infix list)`
+
+Return non-nil if `infix` is infix of `list`.
+
+This operation runs in `o`(n^2) time
+
+```cl
+(-is-infix-p '(1 2 3) '(1 2 3 4 5)) ;; => t
+(-is-infix-p '(2 3 4) '(1 2 3 4 5)) ;; => t
+(-is-infix-p '(3 4 5) '(1 2 3 4 5)) ;; => t
+```
+
 
 ## Partitioning
 
diff --git a/dash.el b/dash.el
index 4d4ef4e..0022076 100644
--- a/dash.el
+++ b/dash.el
@@ -1016,6 +1016,30 @@ The order of the elements in the lists does not matter."
 
 (defalias '-same-items-p '-same-items?)
 
+(defun -is-prefix-p (prefix list)
+  "Return non-nil if PREFIX is prefix of LIST."
+  (--each-while list (equal (car prefix) it)
+    (!cdr prefix))
+  (not prefix))
+
+(defun -is-suffix-p (suffix list)
+  "Return non-nil if SUFFIX is suffix of LIST."
+  (-is-prefix-p (nreverse suffix) (nreverse list)))
+
+(defun -is-infix-p (infix list)
+  "Return non-nil if INFIX is infix of LIST.
+
+This operation runs in O(n^2) time"
+  (let (done)
+    (while (and (not done) list)
+      (setq done (-is-prefix-p infix list))
+      (!cdr list))
+    done))
+
+(defalias '-is-prefix? '-is-prefix-p)
+(defalias '-is-suffix? '-is-suffix-p)
+(defalias '-is-infix? '-is-infix-p)
+
 (defun -sort (comparator list)
   "Sort LIST, stably, comparing elements using COMPARATOR.
 Returns the sorted list.  LIST is NOT modified by side effects.
@@ -1355,6 +1379,12 @@ structure such as plist or alist."
                              "-contains-p"
                              "-same-items?"
                              "-same-items-p"
+                             "-is-prefix-p"
+                             "-is-prefix?"
+                             "-is-suffix-p"
+                             "-is-suffix?"
+                             "-is-infix-p"
+                             "-is-infix?"
                              "-sort"
                              "--sort"
                              "-list"
diff --git a/dev/examples.el b/dev/examples.el
index c0ae5bf..4568f60 100644
--- a/dev/examples.el
+++ b/dev/examples.el
@@ -233,7 +233,26 @@
     (-same-items? '(1 2 3) '(3 2 1)) => t
     (-same-items? '(1 2 3) '(1 2 3 4)) => nil
     (-same-items? '((a . 1) (b . 2)) '((a . 1) (b . 2))) => t
-    (-same-items? '(1 2 3) '(2 3 1)) => t))
+    (-same-items? '(1 2 3) '(2 3 1)) => t)
+
+  (defexamples -is-prefix-p
+    (-is-prefix-p '(1 2 3) '(1 2 3 4 5)) => t
+    (-is-prefix-p '(1 2 3 4 5) '(1 2 3)) => nil
+    (-is-prefix-p '(1 3) '(1 2 3 4 5)) => nil
+    (-is-prefix-p '(1 2 3) '(1 2 4 5)) => nil)
+
+  (defexamples -is-suffix-p
+    (-is-suffix-p '(3 4 5) '(1 2 3 4 5)) => t
+    (-is-suffix-p '(1 2 3 4 5) '(3 4 5)) => nil
+    (-is-suffix-p '(3 5) '(1 2 3 4 5)) => nil
+    (-is-suffix-p '(3 4 5) '(1 2 3 5)) => nil)
+
+  (defexamples -is-infix-p
+    (-is-infix-p '(1 2 3) '(1 2 3 4 5)) => t
+    (-is-infix-p '(2 3 4) '(1 2 3 4 5)) => t
+    (-is-infix-p '(3 4 5) '(1 2 3 4 5)) => t
+    (-is-infix-p '(2 3 4) '(1 2 4 5)) => nil
+    (-is-infix-p '(2 4) '(1 2 3 4 5)) => nil))
 
 (def-example-group "Partitioning" nil
   (defexamples -split-at