From 0a6bfa96e02140c76cd80219444ac1b9d42ea197 Mon Sep 17 00:00:00 2001
From: Fredrik Bergroth <fbergroth@gmail.com>
Date: Sat, 9 Jan 2016 18:36:32 +0100
Subject: [PATCH] company-capf: Add :company-prefix-length property function

---
 NEWS.md         |  1 +
 company-capf.el | 12 +++++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index af75ccb6a..fab296c84 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -2,6 +2,7 @@
 
 ## Next
 
+* `company-capf` accepts `:company-prefix-length` property function.
 * New face `company-tooltip-annotation-selection`, used for the annotation in
   the selected tooltip line.
 * `company-clang-objc-templatify` has been renamed to
diff --git a/company-capf.el b/company-capf.el
index 8e2868925..6554782d1 100644
--- a/company-capf.el
+++ b/company-capf.el
@@ -72,9 +72,15 @@
     (`prefix
      (let ((res (company--capf-data)))
        (when res
-         (if (> (nth 2 res) (point))
-             'stop
-           (buffer-substring-no-properties (nth 1 res) (point))))))
+         (let* ((f (plist-get (nthcdr 4 res) :company-prefix-length))
+                (beg (nth 1 res))
+                (end (nth 2 res))
+                (length (and f (funcall f beg (point))))
+                (prefix (buffer-substring-no-properties beg (point))))
+           (cond
+            ((> end (point)) 'stop)
+            (length (cons prefix length))
+            (t prefix))))))
     (`candidates
      (let ((res (company--capf-data)))
        (when res
-- 
2.39.2