Class: MatchData

Inherits:
Object show all
Defined in:
re.c

Overview

MatchData is the type of the special variable $~, and is the type of the object returned by Regexp#match and Regexp#last_match. It encapsulates all the results of a pattern match, results normally accessed through the special variables $&, $', $`, $1, $2, and so on. Matchdata is also known as MatchingData.

Instance Method Summary collapse

Instance Method Details

#[](i) ⇒ Object #[](start, length) ⇒ Array #[](range) ⇒ Array

Match Reference---MatchData acts as an array, and may be accessed using the normal array indexing techniques. mtch[0] is equivalent to the special variable $&, and returns the entire matched string. mtch[1], mtch[2], and so on return the values of the matched backreferences (portions of the pattern between parentheses).

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m[0]       #=> "HX1138"
m[1, 2]    #=> ["H", "X"]
m[1..3]    #=> ["H", "X", "113"]
m[-3, 2]   #=> ["X", "113"]

Overloads:




# File 're.c'

static VALUE
match_aref(argc, argv, match)
int argc;
VALUE *argv;
VALUE match;
{
VALUE idx, rest;

rb_scan_args(argc, argv, "11", &idx, &rest);

if (!NIL_P(rest) || !FIXNUM_P(idx) || FIX2INT(idx) < 0) {
return rb_ary_aref(argc, argv, match_to_a(match));
}

#begin(n) ⇒ Integer

Returns the offset of the start of the nth element of the match array in the string.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.begin(0)   #=> 1
m.begin(2)   #=> 2

Returns:




# File 're.c'

static VALUE
match_begin(match, n)
    VALUE match, n;
{
    int i = NUM2INT(n);

    match_check(match);
    if (i < 0 || RMATCH(match)->regs->num_regs <= i)
    rb_raise(rb_eIndexError, "index %d out of matches", i);

    if (RMATCH(match)->regs->beg[i] < 0)
    return Qnil;

    return INT2FIX(RMATCH(match)->regs->beg[i]);
}

#captures ⇒ Array

Returns the array of captures; equivalent to mtch.to_a[1..-1].

f1,f2,f3,f4 = /(.)(.)(\d+)(\d)/.match("THX1138.").captures
f1    #=> "H"
f2    #=> "X"
f3    #=> "113"
f4    #=> "8"

Returns:




# File 're.c'

static VALUE
match_captures(match)
    VALUE match;
{
    return match_array(match, 1);
}

#end(n) ⇒ Integer

Returns the offset of the character immediately following the end of the nth element of the match array in the string.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.end(0)   #=> 7
m.end(2)   #=> 3

Returns:




# File 're.c'

static VALUE
match_end(match, n)
    VALUE match, n;
{
    int i = NUM2INT(n);

    match_check(match);
    if (i < 0 || RMATCH(match)->regs->num_regs <= i)
    rb_raise(rb_eIndexError, "index %d out of matches", i);

    if (RMATCH(match)->regs->beg[i] < 0)
    return Qnil;

    return INT2FIX(RMATCH(match)->regs->end[i]);
}

#initialize_copy ⇒ Object

:nodoc:




# File 're.c'

static VALUE
match_init_copy(obj, orig)
VALUE obj, orig;
{
if (obj == orig) return obj;

if (!rb_obj_is_instance_of(orig, rb_obj_class(obj))) {
rb_raise(rb_eTypeError, "wrong argument class");
}

#to_s ⇒ String

Returns a string representing obj. The default to_s prints the object's class and an encoding of the object id. As a special case, the top-level object that is the initial execution context of Ruby programs returns "main."

Returns:




# File 're.c'

VALUE
rb_any_to_s(obj)
    VALUE obj;
{
    char *cname = rb_obj_classname(obj);
    size_t len;
    VALUE str;

    len = strlen(cname)+6+16;
    str = rb_str_new(0, len); /* 6:tags 16:addr */
    snprintf(RSTRING(str)->ptr, len+1, "#<%s:0x%lx>", cname, obj);
    RSTRING(str)->len = strlen(RSTRING(str)->ptr);
    if (OBJ_TAINTED(obj)) OBJ_TAINT(str);

    return str;
}

#length ⇒ Integer #size ⇒ Integer

Returns the number of elements in the match array.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.length   #=> 5
m.size     #=> 5

Overloads:




# File 're.c'

static VALUE
match_size(match)
    VALUE match;
{
    match_check(match);
    return INT2FIX(RMATCH(match)->regs->num_regs);
}

#offset(n) ⇒ Array

Returns a two-element array containing the beginning and ending offsets of the nth match.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.offset(0)   #=> [1, 7]
m.offset(4)   #=> [6, 7]

Returns:




# File 're.c'

static VALUE
match_offset(match, n)
    VALUE match, n;
{
    int i = NUM2INT(n);

    match_check(match);
    if (i < 0 || RMATCH(match)->regs->num_regs <= i)
    rb_raise(rb_eIndexError, "index %d out of matches", i);

    if (RMATCH(match)->regs->beg[i] < 0)
    return rb_assoc_new(Qnil, Qnil);

    return rb_assoc_new(INT2FIX(RMATCH(match)->regs->beg[i]),
            INT2FIX(RMATCH(match)->regs->end[i]));
}

#post_match ⇒ String

Returns the portion of the original string after the current match. Equivalent to the special variable $'.

m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie")
m.post_match   #=> ": The Movie"

Returns:




# File 're.c'

VALUE
rb_reg_match_post(match)
    VALUE match;
{
    VALUE str;
    long pos;

    if (NIL_P(match)) return Qnil;
    match_check(match);
    if (RMATCH(match)->BEG(0) == -1) return Qnil;
    str = RMATCH(match)->str;
    pos = RMATCH(match)->END(0);
    str = rb_str_substr(str, pos, RSTRING(str)->len - pos);
    if (OBJ_TAINTED(match)) OBJ_TAINT(str);
    return str;
}

#pre_match ⇒ String

Returns the portion of the original string before the current match. Equivalent to the special variable $`.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.pre_match   #=> "T"

Returns:




# File 're.c'

VALUE
rb_reg_match_pre(match)
    VALUE match;
{
    VALUE str;

    if (NIL_P(match)) return Qnil;
    match_check(match);
    if (RMATCH(match)->BEG(0) == -1) return Qnil;
    str = rb_str_substr(RMATCH(match)->str, 0, RMATCH(match)->BEG(0));
    if (OBJ_TAINTED(match)) OBJ_TAINT(str);
    return str;
}

#select([index]) ⇒ Array

Uses each index to access the matching values, returning an array of the corresponding matches.

m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie")
m.to_a               #=> ["HX1138", "H", "X", "113", "8"]
m.select(0, 2, -2)   #=> ["HX1138", "X", "113"]

Returns:




# File 're.c'

static VALUE
match_select(argc, argv, match)
int argc;
VALUE *argv;
VALUE match;
{
if (argc > 0) {
rb_raise(rb_eArgError, "wrong number of arguments (%d for 0)", argc);
}

#length ⇒ Integer #size ⇒ Integer

Returns the number of elements in the match array.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.length   #=> 5
m.size     #=> 5

Overloads:




# File 're.c'

static VALUE
match_size(match)
    VALUE match;
{
    match_check(match);
    return INT2FIX(RMATCH(match)->regs->num_regs);
}

#string ⇒ String

Returns a frozen copy of the string passed in to match.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.string   #=> "THX1138."

Returns:




# File 're.c'

static VALUE
match_string(match)
    VALUE match;
{
    match_check(match);
    return RMATCH(match)->str;  /* str is frozen */
}

#to_a ⇒ Array

Returns the array of matches.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.to_a   #=> ["HX1138", "H", "X", "113", "8"]

Because to_a is called when expanding *variable, there's a useful assignment shortcut for extracting matched fields. This is slightly slower than accessing the fields directly (as an intermediate array is generated).

all,f1,f2,f3 = *(/(.)(.)(\d+)(\d)/.match("THX1138."))
all   #=> "HX1138"
f1    #=> "H"
f2    #=> "X"
f3    #=> "113"

Returns:




# File 're.c'

static VALUE
match_to_a(match)
    VALUE match;
{
    return match_array(match, 0);
}

#to_s ⇒ String

Returns the entire matched string.

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.to_s   #=> "HX1138"

Returns:




# File 're.c'

static VALUE
match_to_s(match)
    VALUE match;
{
    VALUE str = rb_reg_last_match(match);

    if (NIL_P(str)) str = rb_str_new(0,0);
    if (OBJ_TAINTED(match)) OBJ_TAINT(str);
    if (OBJ_TAINTED(RMATCH(match)->str)) OBJ_TAINT(str);
    return str;
}

#select([index]) ⇒ Array

Uses each index to access the matching values, returning an array of the corresponding matches.

m = /(.)(.)(\d+)(\d)/.match("THX1138: The Movie")
m.to_a               #=> ["HX1138", "H", "X", "113", "8"]
m.select(0, 2, -2)   #=> ["HX1138", "X", "113"]

Returns:




# File 're.c'

static VALUE
match_values_at(argc, argv, match)
    int argc;
    VALUE *argv;
    VALUE match;
{
    match_check(match);
    return rb_values_at(match, RMATCH(match)->regs->num_regs, argc, argv, match_entry);
}