string.ss: String Utilities
To load: (require (lib "string.ss"))
(eval-string str [err-display err-result]) PROCEDURE
Reads and evaluates S-expressions from the string str, returning
a result for each expression. Note that if str contains only
whitespace and comments, zero values are returned, while if str
contains two expressions, two values are returned.
If err-display is not #f (the default), then errors are
caught and err-display is used as the error display handler. If
err-result is specified, it must be a thunk
that returns a value to be returned when an error is caught;
otherwise, #f is returned when an error is caught.
Prints expr into a string and returns the string.
(read-from-string str [err-display err-result]) PROCEDURE
Reads the first S-expression from the string str and returns it.
The err-display and err-result are as in eval-str.
(read-from-string-all str [err-display err-result]) PROCEDURE
Reads all S-expressions from the string str and returns them in a list.
The err-display and err-result are as in eval-str.
(regexp-match* pattern string-or-input-port [start-k end-k]) PROCEDURE
Like regexp-match (see section 10 in PLT MzScheme: Language Manual), but the result is
a list of strings corresponding to a sequence of matches of
pattern in string-or-input-port. (Unlike
regexp-match, results for parenthesized sub-patterns in
pattern are not returned.) If pattern matches a
zero-length string along the way, the exn:fail exception is raised.
If string-or-input-port contains no matches (in the range
start-k to end-k), null is returned. Otherwise,
each string in the resulting list is a distinct substring in
string-or-input-port that matches pattern. The
end-k argument can be #f to match to the end of
string-or-input-port.
(regexp-match/fail-without-reading pattern input-port [start-k end-k output-port]) PROCEDURE
Like regexp-match on input ports (see section 10 in PLT MzScheme: Language Manual),
except that if the match fails, no characters are read and discarded
from input-port.
This procedure is especially useful with a pattern that begins
with a start-of-string caret (``^'') or with a non-#f
end-k, since each limits the amount of peeking into the port.
(regexp-match-exact? pattern string-or-input-port) PROCEDURE
This procedure is like MzScheme's built-in regexp-match (see
section 10 in PLT MzScheme: Language Manual), but the result is always #t or
#f; #t is only returned when the entire content of
string-or-input-port matches pattern.
(regexp-match-peek-positions* pattern input-port [start-k end-k]) PROCEDURE
Like regexp-match-positions*, but it works only on input ports, and
the port is peeked instead of read for matches.
(regexp-match-positions* pattern string-or-input-port [start-k end-k]) PROCEDURE
Like regexp-match-positions (see section 10 in PLT MzScheme: Language Manual), but the
result is a list of integer pairs corresponding to a sequence of
matches of pattern in string-or-input-port. (Unlike
regexp-match-positions, results for parenthesized
sub-patterns in pattern are not returned.) If pattern
matches a zero-length string along the way, the exn:fail exception is raised.
If string-or-input-port contains no matches (in the range
start-k to end-k), null is returned. Otherwise,
each position pair in the resulting list corresponds to a distinct
substring in string-or-input-port that matches
pattern. The end-k argument can be #f to match
to the end of string-or-input-port.
(regexp-quote str [case-sensitive?]) PROCEDURE
Produces a string suitable for use with regexpstr. If case-sensitive? is true, the resulting regexp
matches letters in str case-insensitively, otherwise (and by
default) it matches case-sensitively.
(regexp-replace-quote str) PROCEDURE
Produces a string suitable for use as the third argument to
regexp-replacestr as a replacement. Concretely,
every backslash and ampersand in str is protected by a quoting
backslash.
(regexp-split pattern string-or-input-port [start-k end-k]) PROCEDURE
The complement of regexp-match* (see above): the result is a
list of sub-strings in string-or-input-port that are separated by
matches to pattern; adjacent matches are separated with
"". If pattern matches a zero-length string along the
way, the exn:fail exception is raised.
If string-or-input-port contains no matches (in the range
start-k to end-k), the result will be a list containing
string-or-input-port (from start-k to end-k). If a
match occurs at the beginning of string-or-input-port (at
start-k), the resulting list will start with an empty string,
and if a match occurs at the end (at end-k), the list will end
with an empty string. The end-k argument can be #f, in
which case splitting goes to the end of string-or-input-port.
(string-lowercase! str) PROCEDURE
Destructively changes str to contain only lowercase characters.
(string-uppercase! str) PROCEDURE
Destructively changes str to contain only uppercase characters.