* lib.c (num_str): Much more accurate test for deciding whether

to treat the number as floating or integer. We can't just look
for the presence of E, e or . because these coudl be part of
trailing junk for instance "123XYZE." should convert
to the integer 123, where "XYZE." is trailing junk.

* txr.1: Documented int-str, flo-str and num-str.

3 files changed, 57 insertions, 7 deletions

diff --git a/ChangeLog b/ChangeLog
index 6efe4902..25da9e32 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2012-03-30  Kaz Kylheku  <kaz@kylheku.com>
+
+	* lib.c (num_str): Much more accurate test for deciding whether
+	to treat the number as floating or integer. We can't just look
+	for the presence of E, e or . because these coudl be part of
+	trailing junk for instance "123XYZE." should convert
+	to the integer 123, where "XYZE." is trailing junk.
+
+	* txr.1: Documented int-str, flo-str and num-str.
+
 2012-03-29  Kaz Kylheku  <kaz@kylheku.com>
 
 	* arith.c (numeq): Fix misplaced parenthesis.
diff --git a/lib.c b/lib.c
index eb756086..186a4a8c 100644
--- a/lib.c
+++ b/lib.c
@@ -1998,9 +1998,12 @@ val flo_str(val str)
 val num_str(val str)
 {
   const wchar_t *wcs = c_str(str);
-  if (wcspbrk(wcs, L".eE"))
-    return flo_str(str);
-  return int_str(str, nil);
+  const wchar_t *nws = wcs + wcsspn(wcs, L"\f\n\r\t\v");
+  const wchar_t *dig = nws + wcsspn(wcs, L"+-");
+
+  if (wcsspn(dig, L"0123456789") == wcsspn(dig, L"0123456789eE."))
+    return int_str(str, nil);
+  return flo_str(str);
 }
 
 val chrp(val chr)
diff --git a/txr.1 b/txr.1
index 13724a41..3bcd65e9 100644
--- a/txr.1
+++ b/txr.1
@@ -7112,6 +7112,47 @@ however, the original unconverted values are returned. For instance
 If three or more arguments are given, max and min are left-associative.
 Thus (max a b c) is (max (max a b) c).
 
+.SS Functions int-str, flo-str and num-str
+
+.TP
+Syntax:
+
+  (int-str <string> <radix>)
+  (flo-str <string>)
+  (num-str <string>)
+
+.TP
+Description:
+
+These functions extract numbers from a string. Leading whitespace, if
+any, is skipped. If no digits can be successfully extracted, then nil is
+returned.  Trailing material which does not contribute to the number
+is ignored.
+
+The int-str function converts a string of digits in the specified
+radix to an integer value. For radices above 10, letters of the alphabet
+are used for digits: A represent a digit whose value is 10, B represents 11 and
+so forth until Z.  For values of radix above 36, the returned value is
+unspecified. Upper and lower case letters are recognized.
+Any character which is not a digit of the specified radix is regarded
+as the start of trailing junk at which the extraction of the digits stops.
+
+The flo-str function converts a floating-point decimal notation to a nearby
+floating point value. The material which contributes to the value
+is the longest match for optional leading space, followed by a
+mantissa which consists of an optional sign followed by a mixture of at least
+one digit, and at most one decimal point, optionally followed by an exponent
+part denoted by the letter E or e, an optional sign and one or more optional
+exponent digits.
+
+The num-str function converts a decimal notation to either an integer as if by
+a radix 10 application of int-str, or to a floating point value as if by
+flo-str. The floating point interpretation is chosen if the possibly empty
+initial sequence of digits (following any whitespace and optional sign) is
+followed by a period, e or E.
+
+.SS Functions int-flo and flo-int
+
 .SS Functions search-regex and match-regex
 
 .SS Function regsub
@@ -7230,10 +7271,6 @@ Thus (max a b c) is (max (max a b) c).
 
 .SS Function string-lt
 
-.SS Functions int-str, flo-str and num-str
-
-.SS Functions int-flo and flo-int
-
 .SS Function chrp
 
 .SS Function chr-isalnum