Adding functions fr^$, fr^, fr$ and frr.

* regex.c (regex_range_full_fun, regex_range_left_fun,
regex_range_right_fun, regex_range_search_fun): New functions.
(regex_init): Register fr^$, fr^, fr$ and frr intrinsics.

* txr.1: Documented.

3 files changed, 109 insertions, 0 deletions

diff --git a/regex.c b/regex.c
index bd6ed971..1f645ead 100644
--- a/regex.c
+++ b/regex.c
@@ -2928,6 +2928,30 @@ val regex_range_all(val regex, val arg1, val arg2, val arg3)
   }
 }
 
+val regex_range_full_fun(val regex, val pos)
+{
+  return curry_123_3(func_n3(regex_range_full),
+                     regex, default_arg(pos, zero));
+}
+
+val regex_range_left_fun(val regex, val pos)
+{
+  return curry_123_3(func_n3(regex_range_left),
+                     regex, default_arg(pos, zero));
+}
+
+val regex_range_right_fun(val regex, val end)
+{
+  if (null_or_missing_p(end))
+    return curry_123_2(func_n3(regex_range_right), regex, end);
+  return curry_123_3(func_n3(regex_range_left), regex, end);
+}
+
+val regex_range_search_fun(val regex, val start, val from_end)
+{
+  return curry_1234_1(func_n4(range_regex), regex, start, from_end);
+}
+
 val read_until_match(val regex, val stream_in, val include_match_in)
 {
   regex_machine_t regm;
@@ -3116,6 +3140,10 @@ void regex_init(void)
   reg_fun(intern(lit("r$"), user_package), func_n3o(regex_range_right, 2));
   reg_fun(intern(lit("rr"), user_package), func_n4o(regex_range_search, 2));
   reg_fun(intern(lit("rra"), user_package), func_n4o(regex_range_all, 2));
+  reg_fun(intern(lit("fr^$"), user_package), func_n2o(regex_range_full_fun, 1));
+  reg_fun(intern(lit("fr^"), user_package), func_n2o(regex_range_left_fun, 1));
+  reg_fun(intern(lit("fr$"), user_package), func_n2o(regex_range_right_fun, 1));
+  reg_fun(intern(lit("frr"), user_package), func_n3o(regex_range_search_fun, 1));
   init_special_char_sets();
 }
 
diff --git a/regex.h b/regex.h
index 8d51669c..fd2cc196 100644
--- a/regex.h
+++ b/regex.h
@@ -55,6 +55,10 @@ val regex_range_left(val regex, val arg1, val arg2);
 val regex_range_right(val regex, val arg1, val arg2);
 val regex_range_search(val regex, val arg1, val arg2, val arg3);
 val regex_range_all(val regex, val arg1, val arg2, val arg3);
+val regex_range_full_fun(val regex, val pos);
+val regex_range_left_fun(val regex, val pos);
+val regex_range_right_fun(val regex, val end);
+val regex_range_search_fun(val regex, val start, val from_end);
 int wide_display_char_p(wchar_t ch);
 void regex_init(void);
 void regex_free_all(void);
diff --git a/txr.1 b/txr.1
index 309a1ea5..255e90ec 100644
--- a/txr.1
+++ b/txr.1
@@ -34623,6 +34623,83 @@ and
   --> nil
 .cble
 
+.coNP Functions @, fr^$ @, fr^ @ fr$ and @ frr
+.synb
+.mets (fr^$ < regex <> [ position ])
+.mets (fr^ < regex <> [ position ])
+.mets (fr$ < regex <> [ end-position ])
+.mets (frr < regex <> [[ start-position ] << from-end ])
+.syne
+.desc
+These regular expression functions do not directly
+perform regex operations. Rather, they each return
+a function of one argument which performs a regex
+operation.
+
+The returned functions perform the same operations as,
+respectively,
+.codn r^$ ,
+.codn r^ ,
+.code r$
+and
+.codn rr .
+
+The following equivalences nearly hold, except that some of the 
+functions on the right side produced by op
+.code op
+can accept additional arguments after the input string,
+whereas the functions on the left produced by
+.code f^$
+.I "et al."
+accept only one parameter: the input string.
+
+.cblk
+  [fr^$ r]     <-->  (op m^$ r)
+  [fr^$ r p]   <-->  (op m^$ r p)
+  [fr^ r]      <-->  (op m^ r)
+  [fr^ r p]    <-->  (op m^ r p)
+  [fr$ r]      <-->  (op m$ r)
+  [fr$ r p]    <-->  (op m$ r p)
+  [frr r]      <-->  (op m$ r)
+  [frr r s]    <-->  (op m$ r s)
+  [frr r s fe] <-->  (op m$ r s fe)
+.cble
+
+That is to say,
+.code fr^$
+returns a function which binds
+.meta regex
+and possibly the optional
+.metn position .
+When this function is invoked, it must be given an argument
+which is a string. It performs the same operation as
+.code r^$
+being called on
+.meta regex
+and possibly
+.metn position ,
+and the string.
+The same holds between
+.code fr^
+and
+.codn r^ ,
+between
+.code fr$
+and
+.codn r$ ,
+and between
+.code frr
+and
+.codn rr .
+
+.TP* Examples:
+
+.cblk
+  ;; Remove leading digits from "123A456", other than first digit:
+  (regsub (fr^ #/\ed+/ 1) "" "123A456")
+  --> "1A456"
+.cble
+
 .SS* Hashing Library
 .coNP Functions @ make-hash and @ hash
 .synb