StringScanner#match?

(::Regexp) -> ::Integer?

match?(pattern) → updated_position or nil

static VALUE
strscan_match_p(VALUE self, VALUE re)
{
    return strscan_do_scan(self, re, 0, 0, 1);
}

Attempts to match the given pattern at the beginning of the target substring; does not modify the positions.

If the match succeeds:

Sets match values.
Returns the size in bytes of the matched substring.

Example

scanner = StringScanner.new('foobarbaz')
scanner.pos = 3
scanner.match?(/bar/) => 3
put_match_values(scanner)
# Basic match values:
#   matched?:       true
#   matched_size:   3
#   pre_match:      "foo"
#   matched  :      "bar"
#   post_match:     "baz"
# Captured match values:
#   size:           1
#   captures:       []
#   named_captures: {}
#   values_at:      ["bar", nil]
#   []:
#     [0]:          "bar"
#     [1]:          nil
put_situation(scanner)
# Situation:
#   pos:       3
#   charpos:   3
#   rest:      "barbaz"
#   rest_size: 6

If the match fails:

Clears match values.
Returns nil.
Does not increment positions.

Example

scanner.match?(/nope/)         # => nil
match_values_cleared?(scanner) # => true

See also #inspect #matched #initialize_copy #matched? also in 4.1 · 4.0 · 3.3 · 3.2 · 3.1 · 3.0

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