Regular expression replacement using results of calling a procedure

0001-Add-regex-replacement-using-results-of-calling-a-pro.patch

From 6ae230f9c9809141deea110900a36242ac9256dc Mon Sep 17 00:00:00 2001
From: Oleh Prypin <[email protected]>
Date: Thu, 8 Jan 2015 00:09:07 +0200
Subject: [PATCH] Add regex replacement using results of calling a procedure

---
 lib/impure/re.nim | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/lib/impure/re.nim b/lib/impure/re.nim
index a7bebb8..be57c8f 100644
--- a/lib/impure/re.nim
+++ b/lib/impure/re.nim
@@ -327,6 +327,35 @@ proc replacef*(s: string, sub: Regex, by: string): string =
     prev = match.last + 1
   add(result, substr(s, prev))
 
+proc replace*(s: string, sub: Regex, by: proc(s: string): string): string =
+  ## Replaces `sub` in `s` by the results of calling the proc `by` with
+  ## each matched string.
+  result = ""
+  var prev = 0
+  while true:
+    var match = findBounds(s, sub, prev)
+    if match.first < 0: break
+    add(result, substr(s, prev, match.first-1))
+    add(result, by(substr(s, match.first, match.last)))
+    prev = match.last + 1
+  add(result, substr(s, prev))
+
+proc replacef*(s: string, sub: Regex, 
+               by: proc(m: openArray[string]): string): string =
+  ## Replaces `sub` in `s` by the results of calling the proc `by` with
+  ## each array of captures.
+  result = ""
+  var caps: array[0..MaxSubpatterns-1, string]
+  var prev = 0
+  while true:
+    var match = findBounds(s, sub, caps, prev)
+    if match.first < 0: break
+    add(result, substr(s, prev, match.first-1))
+    let capCount = find(caps, string(nil))
+    add(result, by(caps[0..capCount-1]))
+    prev = match.last + 1
+  add(result, substr(s, prev))
+
 proc parallelReplace*(s: string, subs: openArray[
                       tuple[pattern: Regex, repl: string]]): string =
   ## Returns a modified copy of `s` with the substitutions in `subs`
-- 
2.2.1

re_procs.nim

import re, strutils


proc replace*(s: string, sub: Regex, by: proc(s: string): string): string =
  ## Replaces `sub` in `s` by the results of calling the proc `by` with
  ## each matched string.
  result = ""
  var prev = 0
  while true:
    var match = findBounds(s, sub, prev)
    if match.first < 0: break
    add(result, substr(s, prev, match.first-1))
    add(result, by(substr(s, match.first, match.last)))
    prev = match.last + 1
  add(result, substr(s, prev))

echo "particles are particularly interesting".replace(re"part", toUpper)
# PARTicles are PARTicularly interesting


proc replacef*(s: string, sub: Regex, 
               by: proc(m: openArray[string]): string): string =
  ## Replaces `sub` in `s` by the results of calling the proc `by` with
  ## each array of captures.
  result = ""
  var caps: array[0..MaxSubpatterns-1, string]
  var prev = 0
  while true:
    let match = findBounds(s, sub, caps, prev)
    if match.first < 0: break
    add(result, substr(s, prev, match.first-1))
    let capCount = find(caps, string(nil))
    add(result, by(caps[0..capCount-1]))
    prev = match.last + 1
  add(result, substr(s, prev))

echo "RUMPF Andreas, DUMEZ Cristophe".replacef(
  re"\b([A-Z]{3,})\ ([A-Z][a-z]{2,})\b") do (m: openarray[string]) -> string:
    "$2 $1" % m.map(toLower).map(capitalize)
# Andreas Rumpf, Cristophe Dumez