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YAML + DBM = YDBM

YAML::DBM provides the same interface as ::DBM.

However, while DBM only allows strings for both keys and values, this library allows one to use most Ruby objects for values by first converting them to YAML. Keys must be strings.

Conversion to and from YAML is performed automatically.

See the documentation for ::DBM and ::YAML for more information.

Methods
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Instance Public methods

ydbm[key] → value

Return value associated with key from database.

Returns nil if there is no such key.

See fetch for more information.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 29
def []( key )
    fetch( key )
end

ydbm[key] = value

Set key to value in database.

value will be converted to YAML before storage.

See store for more information.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 41
def []=( key, val )
    store( key, val )
end

ydbm.delete(key)

Deletes value from database associated with key.

Returns value or nil.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 102
def delete( key )
    v = super( key )
    if String === v
        v = YAML.load( v )
    end
    v
end

ydbm.delete_if { |key, value| ... }

Calls the given block once for each key, value pair in the database. Deletes all entries for which the block returns true.

Returns self.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 117
def delete_if # :yields: [key, value]
    del_keys = keys.dup
    del_keys.delete_if { |k| yield( k, fetch( k ) ) == false }
    del_keys.each { |k| delete( k ) }
    self
end

each()

Alias for: each_pair

each_pair()

Calls the given block once for each key, value pair in the database.

Returns self.

Also aliased as: each

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 140
def each_pair # :yields: [key, value]
    keys.each { |k| yield k, fetch( k ) }
    self
end

ydbm.each_value { |value| ... }

Calls the given block for each value in database.

Returns self.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 151
def each_value # :yields: value
    super { |v| yield YAML.load( v ) }
    self
end

ydbm.fetch( key, ifnone = nil )
ydbm.fetch( key ) { |key| ... }

Return value associated with key.

If there is no value for key and no block is given, returns ifnone.

Otherwise, calls block passing in the given key.

See ::DBM#fetch for more information.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 56
def fetch( keystr, ifnone = nil )
    begin
        val = super( keystr )
        return YAML.load( val ) if String === val
    rescue IndexError
    end
    if block_given?
        yield keystr
    else
        ifnone
    end
end

ydbm.has_value?(value)

Returns true if specified value is found in the database.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 168
def has_value?( val )
    each_value { |v| return true if v == val }
    return false
end

index( keystr )

Deprecated, used YAML::DBM#key instead.

Note: YAML::DBM#index makes warning from internal of ::DBM#index. It says ‘DBM#index is deprecated; use DBM#key’, but DBM#key behaves not same as DBM#index.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 76
def index( keystr )
    super( keystr.to_yaml )
end

ydbm.invert → hash

Returns a Hash (not a DBM database) created by using each value in the database as a key, with the corresponding key as its value.

Note that all values in the hash will be Strings, but the keys will be actual objects.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 181
def invert
    h = {}
    keys.each { |k| h[ self.fetch( k ) ] = k }
    h
end

ydbm.key(value) → string

Returns the key for the specified value.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 84
def key( keystr )
    invert[keystr]
end

ydbm.reject { |key, value| ... }

Converts the contents of the database to an in-memory Hash, then calls Hash#reject with the specified code block, returning a new Hash.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 129
def reject
    hsh = self.to_hash
    hsh.reject { |k,v| yield k, v }
end

ydbm.replace(hash) → ydbm

Replaces the contents of the database with the contents of the specified object. Takes any object which implements the each_pair method, including Hash and DBM objects.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 193
def replace( hsh )
    clear
    update( hsh )
end

ydbm.select { |key, value| ... }
ydbm.select(*keys)

If a block is provided, returns a new array containing [key, value] pairs for which the block returns true.

Otherwise, same as values_at

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 219
def select( *keys )
    if block_given?
        self.keys.collect { |k| v = self[k]; [k, v] if yield k, v }.compact
    else
        values_at( *keys )
    end
end

ydbm.shift → [key, value]

Removes a [key, value] pair from the database, and returns it. If the database is empty, returns nil.

The order in which values are removed/returned is not guaranteed.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 205
def shift
    a = super
    a[1] = YAML.load( a[1] ) if a
    a
end

ydbm.store(key, value) → value

Stores value in database with key as the index. value is converted to YAML before being stored.

Returns value

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 234
def store( key, val )
    super( key, val.to_yaml )
    val
end

ydbm.to_a → array

Converts the contents of the database to an array of [key, value] arrays, and returns it.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 259
def to_a
    a = []
    keys.each { |k| a.push [ k, self.fetch( k ) ] }
    a
end

ydbm.to_hash → hash

Converts the contents of the database to an in-memory Hash object, and returns it.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 271
def to_hash
    h = {}
    keys.each { |k| h[ k ] = self.fetch( k ) }
    h
end

ydbm.update(hash) → ydbm

Updates the database with multiple values from the specified object. Takes any object which implements the each_pair method, including Hash and DBM objects.

Returns self.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 247
def update( hsh )
    hsh.each_pair do |k,v|
        self.store( k, v )
    end
    self
end

ydbm.values

Returns an array of values from the database.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 160
def values
    super.collect { |v| YAML.load( v ) }
end

ydbm.values_at(*keys)

Returns an array containing the values associated with the given keys.

Source: show | on GitHub 

# File ruby/lib/yaml/dbm.rb, line 92
def values_at( *keys )
    keys.collect { |k| fetch( k ) }
end