A Regexp holds a regular expression, used to match a pattern against strings. Regexps are created using the /.../ and %r{...} literals, and by the Regexp::new constructor.
- #
- C
- E
- H
- I
- K
- L
- M
- N
- O
- Q
- S
- T
- U
- Y
- #
| IGNORECASE | = | INT2FIX(RE_OPTION_IGNORECASE) |
| EXTENDED | = | INT2FIX(RE_OPTION_EXTENDED) |
| MULTILINE | = | INT2FIX(RE_OPTION_MULTILINE) |
Synonym for Regexp.new
Escapes any characters that would have special meaning in a regular expression. Returns a new escaped string, or self if no characters are escaped. For any string, Regexp.escape(str)=~str will be true.
Regexp.escape('\\*?{}.') #=> \\\\\*\?\{\}\.
Source: show
static VALUE
rb_reg_s_quote(argc, argv)
int argc;
VALUE *argv;
{
VALUE str, kcode;
int kcode_saved = reg_kcode;
rb_scan_args(argc, argv, "11", &str, &kcode);
if (!NIL_P(kcode)) {
rb_set_kcode(StringValuePtr(kcode));
curr_kcode = reg_kcode;
reg_kcode = kcode_saved;
}
StringValue(str);
str = rb_reg_quote(str);
rb_kcode_reset_option();
return str;
}
The first form returns the MatchData object generated by the last successful pattern match. Equivalent to reading the global variable $~. The second form returns the nth field in this MatchData object.
/c(.)t/ =~ 'cat' #=> 0 Regexp.last_match #=> #<MatchData:0x401b3d30> Regexp.last_match(0) #=> "cat" Regexp.last_match(1) #=> "a" Regexp.last_match(2) #=> nil
Source: show
static VALUE
rb_reg_s_last_match(argc, argv)
int argc;
VALUE *argv;
{
VALUE nth;
if (rb_scan_args(argc, argv, "01", &nth) == 1) {
return rb_reg_nth_match(NUM2INT(nth), rb_backref_get());
}
return match_getter();
}
Constructs a new regular expression from pattern, which can be either a String or a Regexp (in which case that regexp’s options are propagated, and new options may not be specified (a change as of Ruby 1.8). If options is a Fixnum, it should be one or more of the constants Regexp::EXTENDED, Regexp::IGNORECASE, and Regexp::MULTILINE, or-ed together. Otherwise, if options is not nil, the regexp will be case insensitive. The lang parameter enables multibyte support for the regexp: `n’, `N’ = none, `e’, `E’ = EUC, `s’, `S’ = SJIS, `u’, `U’ = UTF-8.
r1 = Regexp.new('^a-z+:\\s+\w+') #=> /^a-z+:\s+\w+/
r2 = Regexp.new('cat', true) #=> /cat/i
r3 = Regexp.new('dog', Regexp::EXTENDED) #=> /dog/x
r4 = Regexp.new(r2) #=> /cat/i
Source: show
static VALUE
rb_reg_initialize_m(argc, argv, self)
int argc;
VALUE *argv;
VALUE self;
{
const char *s;
long len;
int flags = 0;
if (argc == 0 || argc > 3) {
rb_raise(rb_eArgError, "wrong number of arguments");
}
if (TYPE(argv[0]) == T_REGEXP) {
if (argc > 1) {
rb_warn("flags%s ignored", (argc == 3) ? " and encoding": "");
}
rb_reg_check(argv[0]);
flags = RREGEXP(argv[0])->ptr->options & 0xf;
if (FL_TEST(argv[0], KCODE_FIXED)) {
switch (RBASIC(argv[0])->flags & KCODE_MASK) {
case KCODE_NONE:
flags |= 16;
break;
case KCODE_EUC:
flags |= 32;
break;
case KCODE_SJIS:
flags |= 48;
break;
case KCODE_UTF8:
flags |= 64;
break;
default:
break;
}
}
s = RREGEXP(argv[0])->str;
len = RREGEXP(argv[0])->len;
}
else {
if (argc >= 2) {
if (FIXNUM_P(argv[1])) flags = FIX2INT(argv[1]);
else if (RTEST(argv[1])) flags = RE_OPTION_IGNORECASE;
}
if (argc == 3 && !NIL_P(argv[2])) {
char *kcode = StringValuePtr(argv[2]);
flags &= ~0x70;
switch (kcode[0]) {
case 'n': case 'N':
flags |= 16;
break;
case 'e': case 'E':
flags |= 32;
break;
case 's': case 'S':
flags |= 48;
break;
case 'u': case 'U':
flags |= 64;
break;
default:
break;
}
}
s = StringValuePtr(argv[0]);
len = RSTRING(argv[0])->len;
}
rb_reg_initialize(self, s, len, flags);
return self;
}
Escapes any characters that would have special meaning in a regular expression. Returns a new escaped string, or self if no characters are escaped. For any string, Regexp.escape(str)=~str will be true.
Regexp.escape('\\*?{}.') #=> \\\\\*\?\{\}\.
Source: show
static VALUE
rb_reg_s_quote(argc, argv)
int argc;
VALUE *argv;
{
VALUE str, kcode;
int kcode_saved = reg_kcode;
rb_scan_args(argc, argv, "11", &str, &kcode);
if (!NIL_P(kcode)) {
rb_set_kcode(StringValuePtr(kcode));
curr_kcode = reg_kcode;
reg_kcode = kcode_saved;
}
StringValue(str);
str = rb_reg_quote(str);
rb_kcode_reset_option();
return str;
}
Return a Regexp object that is the union of the given patterns, i.e., will match any of its parts. The patterns can be Regexp objects, in which case their options will be preserved, or Strings. If no patterns are given, returns /(?!)/.
Regexp.union #=> /(?!)/
Regexp.union("penzance") #=> /penzance/
Regexp.union("a+b*c") #=> /a\+b\*c/
Regexp.union("skiing", "sledding") #=> /skiing|sledding/
Regexp.union(["skiing", "sledding"]) #=> /skiing|sledding/
Regexp.union(/dogs/, /cats/i) #=> /(?-mix:dogs)|(?i-mx:cats)/
Source: show
static VALUE
rb_reg_s_union_m(VALUE self, VALUE args)
{
VALUE v;
if (RARRAY_LEN(args) == 1 &&
!NIL_P(v = rb_check_array_type(rb_ary_entry(args, 0)))) {
return rb_reg_s_union(self, v);
}
return rb_reg_s_union(self, args);
}
Source: show
# File lib/yaml/rubytypes.rb, line 255 255: def Regexp.yaml_new( klass, tag, val ) 256: if String === val and val =~ /^\/(.*)\/([mix]*)$/ 257: val = { 'regexp' => $1, 'mods' => $2 } 258: end 259: if Hash === val 260: mods = nil 261: unless val['mods'].to_s.empty? 262: mods = 0x00 263: mods |= Regexp::EXTENDED if val['mods'].include?( 'x' ) 264: mods |= Regexp::IGNORECASE if val['mods'].include?( 'i' ) 265: mods |= Regexp::MULTILINE if val['mods'].include?( 'm' ) 266: end 267: val.delete( 'mods' ) 268: r = YAML::object_maker( klass, {} ) 269: Regexp.instance_method(:initialize). 270: bind(r). 271: call( val.delete( 'regexp' ), mods ) 272: val.each { |k,v| r.instance_variable_set( k, v ) } 273: r 274: else 275: raise YAML::TypeError, "Invalid Regular expression: " + val.inspect 276: end 277: end
Source: show
# File lib/eregex.rb, line 29 29: def &(other) 30: RegAnd.new(self, other) 31: end
Equality—Two regexps are equal if their patterns are identical, they have the same character set code, and their casefold? values are the same.
/abc/ == /abc/x #=> false /abc/ == /abc/i #=> false /abc/u == /abc/n #=> false
Source: show
static VALUE
rb_reg_equal(re1, re2)
VALUE re1, re2;
{
if (re1 == re2) return Qtrue;
if (TYPE(re2) != T_REGEXP) return Qfalse;
rb_reg_check(re1); rb_reg_check(re2);
if (RREGEXP(re1)->len != RREGEXP(re2)->len) return Qfalse;
if (memcmp(RREGEXP(re1)->str, RREGEXP(re2)->str, RREGEXP(re1)->len) == 0 &&
rb_reg_cur_kcode(re1) == rb_reg_cur_kcode(re2) &&
RREGEXP(re1)->ptr->options == RREGEXP(re2)->ptr->options) {
return Qtrue;
}
return Qfalse;
}
Case Equality—Synonym for Regexp#=~ used in case statements.
a = "HELLO" case a when /^[a-z]*$/; print "Lower case\n" when /^[A-Z]*$/; print "Upper case\n" else; print "Mixed case\n" end
produces:
Upper case
Source: show
VALUE
rb_reg_eqq(re, str)
VALUE re, str;
{
long start;
if (TYPE(str) != T_STRING) {
str = rb_check_string_type(str);
if (NIL_P(str)) {
rb_backref_set(Qnil);
return Qfalse;
}
}
StringValue(str);
start = rb_reg_search(re, str, 0, 0);
if (start < 0) {
return Qfalse;
}
return Qtrue;
}
Returns a MatchData object describing the match, or nil if there was no match. This is equivalent to retrieving the value of the special variable $~ following a normal match.
/(.)(.)(.)/.match("abc")[2] #=> "b"
Source: show
VALUE
rb_reg_match(re, str)
VALUE re, str;
{
long start;
if (NIL_P(str)) {
rb_backref_set(Qnil);
return Qnil;
}
StringValue(str);
start = rb_reg_search(re, str, 0, 0);
if (start < 0) {
return Qnil;
}
return LONG2FIX(start);
}
Returns the value of the case-insensitive flag.
Source: show
static VALUE
rb_reg_casefold_p(re)
VALUE re;
{
rb_reg_check(re);
if (RREGEXP(re)->ptr->options & RE_OPTION_IGNORECASE) return Qtrue;
return Qfalse;
}
Equality—Two regexps are equal if their patterns are identical, they have the same character set code, and their casefold? values are the same.
/abc/ == /abc/x #=> false /abc/ == /abc/i #=> false /abc/u == /abc/n #=> false
Source: show
static VALUE
rb_reg_equal(re1, re2)
VALUE re1, re2;
{
if (re1 == re2) return Qtrue;
if (TYPE(re2) != T_REGEXP) return Qfalse;
rb_reg_check(re1); rb_reg_check(re2);
if (RREGEXP(re1)->len != RREGEXP(re2)->len) return Qfalse;
if (memcmp(RREGEXP(re1)->str, RREGEXP(re2)->str, RREGEXP(re1)->len) == 0 &&
rb_reg_cur_kcode(re1) == rb_reg_cur_kcode(re2) &&
RREGEXP(re1)->ptr->options == RREGEXP(re2)->ptr->options) {
return Qtrue;
}
return Qfalse;
}
Produce a hash based on the text and options of this regular expression.
Source: show
static VALUE
rb_reg_hash(re)
VALUE re;
{
int hashval, len;
char *p;
rb_reg_check(re);
hashval = RREGEXP(re)->ptr->options;
len = RREGEXP(re)->len;
p = RREGEXP(re)->str;
while (len--) {
hashval = hashval * 33 + *p++;
}
hashval = hashval + (hashval>>5);
return INT2FIX(hashval);
}
Produce a nicely formatted string-version of rxp. Perhaps surprisingly, inspect actually produces the more natural version of the string than to_s.
/ab+c/ix.to_s #=> /ab+c/ix
Source: show
static VALUE
rb_reg_inspect(re)
VALUE re;
{
rb_reg_check(re);
return rb_reg_desc(RREGEXP(re)->str, RREGEXP(re)->len, re);
}
Returns the character set code for the regexp.
Source: show
static VALUE
rb_reg_kcode_m(re)
VALUE re;
{
const char *kcode;
if (FL_TEST(re, KCODE_FIXED)) {
switch (RBASIC(re)->flags & KCODE_MASK) {
case KCODE_NONE:
kcode = "none"; break;
case KCODE_EUC:
kcode = "euc"; break;
case KCODE_SJIS:
kcode = "sjis"; break;
case KCODE_UTF8:
kcode = "utf8"; break;
default:
rb_bug("unknown kcode - should not happen");
break;
}
return rb_str_new2(kcode);
}
return Qnil;
}
Returns a MatchData object describing the match, or nil if there was no match. This is equivalent to retrieving the value of the special variable $~ following a normal match.
/(.)(.)(.)/.match("abc")[2] #=> "b"
Source: show
static VALUE
rb_reg_match_m(re, str)
VALUE re, str;
{
VALUE result = rb_reg_match(re, str);
if (NIL_P(result)) return Qnil;
result = rb_backref_get();
rb_match_busy(result);
return result;
}
Returns the set of bits corresponding to the options used when creating this Regexp (see Regexp::new for details. Note that additional bits may be set in the returned options: these are used internally by the regular expression code. These extra bits are ignored if the options are passed to Regexp::new.
Regexp::IGNORECASE #=> 1
Regexp::EXTENDED #=> 2
Regexp::MULTILINE #=> 4
/cat/.options #=> 128
/cat/ix.options #=> 131
Regexp.new('cat', true).options #=> 129
Regexp.new('cat', 0, 's').options #=> 384
r = /cat/ix
Regexp.new(r.source, r.options) #=> /cat/ix
Source: show
static VALUE
rb_reg_options_m(re)
VALUE re;
{
int options = rb_reg_options(re);
return INT2NUM(options);
}
Returns the original string of the pattern.
/ab+c/ix.source #=> "ab+c"
Source: show
static VALUE
rb_reg_source(re)
VALUE re;
{
VALUE str;
rb_reg_check(re);
str = rb_str_new(RREGEXP(re)->str,RREGEXP(re)->len);
if (OBJ_TAINTED(re)) OBJ_TAINT(str);
return str;
}
Returns a string containing the regular expression and its options (using the (?xxx:yyy) notation. This string can be fed back in to Regexp::new to a regular expression with the same semantics as the original. (However, Regexp#== may not return true when comparing the two, as the source of the regular expression itself may differ, as the example shows). Regexp#inspect produces a generally more readable version of rxp.
r1 = /ab+c/ix #=> /ab+c/ix s1 = r1.to_s #=> "(?ix-m:ab+c)" r2 = Regexp.new(s1) #=> /(?ix-m:ab+c)/ r1 == r2 #=> false r1.source #=> "ab+c" r2.source #=> "(?ix-m:ab+c)"
Source: show
static VALUE
rb_reg_to_s(re)
VALUE re;
{
int options;
const int embeddable = RE_OPTION_MULTILINE|RE_OPTION_IGNORECASE|RE_OPTION_EXTENDED;
long len;
const char* ptr;
VALUE str = rb_str_buf_new2("(?");
rb_reg_check(re);
options = RREGEXP(re)->ptr->options;
ptr = RREGEXP(re)->str;
len = RREGEXP(re)->len;
again:
if (len >= 4 && ptr[0] == '(' && ptr[1] == '?') {
int err = 1;
ptr += 2;
if ((len -= 2) > 0) {
do {
if (*ptr == 'm') {
options |= RE_OPTION_MULTILINE;
}
else if (*ptr == 'i') {
options |= RE_OPTION_IGNORECASE;
}
else if (*ptr == 'x') {
options |= RE_OPTION_EXTENDED;
}
else break;
++ptr;
} while (--len > 0);
}
if (len > 1 && *ptr == '-') {
++ptr;
--len;
do {
if (*ptr == 'm') {
options &= ~RE_OPTION_MULTILINE;
}
else if (*ptr == 'i') {
options &= ~RE_OPTION_IGNORECASE;
}
else if (*ptr == 'x') {
options &= ~RE_OPTION_EXTENDED;
}
else break;
++ptr;
} while (--len > 0);
}
if (*ptr == ')') {
--len;
++ptr;
goto again;
}
if (*ptr == ':' && ptr[len-1] == ')') {
Regexp *rp;
rb_kcode_set_option(re);
rp = ALLOC(Regexp);
MEMZERO((char *)rp, Regexp, 1);
err = re_compile_pattern(++ptr, len -= 2, rp) != 0;
rb_kcode_reset_option();
re_free_pattern(rp);
}
if (err) {
options = RREGEXP(re)->ptr->options;
ptr = RREGEXP(re)->str;
len = RREGEXP(re)->len;
}
}
if (options & RE_OPTION_MULTILINE) rb_str_buf_cat2(str, "m");
if (options & RE_OPTION_IGNORECASE) rb_str_buf_cat2(str, "i");
if (options & RE_OPTION_EXTENDED) rb_str_buf_cat2(str, "x");
if ((options & embeddable) != embeddable) {
rb_str_buf_cat2(str, "-");
if (!(options & RE_OPTION_MULTILINE)) rb_str_buf_cat2(str, "m");
if (!(options & RE_OPTION_IGNORECASE)) rb_str_buf_cat2(str, "i");
if (!(options & RE_OPTION_EXTENDED)) rb_str_buf_cat2(str, "x");
}
rb_str_buf_cat2(str, ":");
rb_reg_expr_str(str, ptr, len);
rb_str_buf_cat2(str, ")");
OBJ_INFECT(str, re);
return str;
}
Source: show
# File lib/yaml/rubytypes.rb, line 278 278: def to_yaml( opts = {} ) 279: YAML::quick_emit( nil, opts ) do |out| 280: if to_yaml_properties.empty? 281: out.scalar( taguri, self.inspect, :plain ) 282: else 283: out.map( taguri, to_yaml_style ) do |map| 284: src = self.inspect 285: if src =~ /\A\/(.*)\/([a-z]*)\Z/ 286: map.add( 'regexp', $1 ) 287: map.add( 'mods', $2 ) 288: else 289: raise YAML::TypeError, "Invalid Regular expression: " + src 290: end 291: to_yaml_properties.each do |m| 292: map.add( m, instance_variable_get( m ) ) 293: end 294: end 295: end 296: end 297: end
Source: show
# File lib/eregex.rb, line 26 26: def |(other) 27: RegOr.new(self, other) 28: end
Match—Matches rxp against the contents of $_. Equivalent to rxp =~ $_.
$_ = "input data" ~ /at/ #=> 7
Source: show
VALUE
rb_reg_match2(re)
VALUE re;
{
long start;
VALUE line = rb_lastline_get();
if (TYPE(line) != T_STRING) {
rb_backref_set(Qnil);
return Qnil;
}
start = rb_reg_search(re, line, 0, 0);
if (start < 0) {
return Qnil;
}
return LONG2FIX(start);
}