Class: Funkr::Types::SimpleRecord

Inherits:
Array show all
Defined in:
lib/funkr/types/simple_record.rb

Overview

Simple records are a simple way to create records with named AND positional fields. Records can be updated on a per-field basis and pattern-matched as arrays. SimpleRecord has the following advantages above plain Hash :

- fields are strict, you can't update an unexisting field by
  mistyping it or by combining it with a different structure
- you have easy access to fields : named AND positional

usage :

r = SimpleRecord.new( name: "Paul", age: 27 )
r.name # => "Paul"
r.age  # => 27
name, age = r  # => [ "Paul", 27 ]
r.with(age: 29)  # => [ "Paul", 29 ]

other usage :

class Person < SimpleRecord; fields :name, :age; end
Person.new( name: Paul ) => Error, missing :age

Class Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Array

#apply, #bind, box, #mplus, mzero, #or_else, #unbox, unit

Constructor Details

#initialize(key_vals) ⇒ SimpleRecord

Create a new SimpleRecord. Pass a Hash of keys and associated values if you want an inline record.



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# File 'lib/funkr/types/simple_record.rb', line 42

def initialize(key_vals)
  fields = self.class.fields_list
  if not fields.nil? then # record paramétré
    if fields == key_vals.keys then # tout va bien
      @allowed_keys = fields
      @key_vals = key_vals
      rebuild_array
    else raise "#{self.class.to_s} wrong initialization, expected #{fields}" end
  else  # record anonyme
    @allowed_keys = key_vals.keys
    @key_vals = key_vals
    key_vals.each do |k,v|
      getter = k.to_sym
      setter = format("%s=", k.to_s).to_sym
      define_singleton_method(getter){ @key_vals[k] }
      define_singleton_method(setter){|nv| @key_vals[k] = nv; rebuild_array}
      self.push(v)
    end
  end
end

Class Attribute Details

.fields_list ⇒ Object

Returns the value of attribute fields_list.



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# File 'lib/funkr/types/simple_record.rb', line 27

def fields_list
  @fields_list
end

Class Method Details

.fields(*flds) ⇒ Object 



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# File 'lib/funkr/types/simple_record.rb', line 30

def self.fields(*flds)
  self.fields_list = flds
  flds.each do |f|
    getter = f.to_sym
    setter = format("%s=", f.to_s).to_sym
    define_method(getter){ @key_vals[f] }
    define_method(setter){|nv| @key_vals[f] = nv; rebuild_array}
  end
end

Instance Method Details

#to_hash ⇒ Object 



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# File 'lib/funkr/types/simple_record.rb', line 77

def to_hash; @key_vals; end

#to_s ⇒ Object 



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# File 'lib/funkr/types/simple_record.rb', line 79

def to_s; @key_vals.to_s; end

#update!(new_key_vals) ⇒ Object

Update a simple record destructively !!



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# File 'lib/funkr/types/simple_record.rb', line 70

def update!(new_key_vals)
  check_keys(new_key_vals.keys)
  @key_vals.merge!(new_key_vals)
  rebuild_array
  self
end

#with(new_key_vals) ⇒ Object

Update a simple record non-destructively



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# File 'lib/funkr/types/simple_record.rb', line 64

def with(new_key_vals)
  check_keys(new_key_vals.keys)
  self.class.new(@key_vals.merge(new_key_vals))
end