matchlist.tiny

######################################################
#
# Pattern matching using patterns as objects and the
# .matchlist() method
#
#######################################################

# A database of people and relationships
rels = [
    ['parent-of', 'Bob',    'Sue'],
    ['gender',    'Bob',    'Male'],
    ['parent-of', 'Bob',    'John'],
    ['gender',    'John',   'Male'],
    ['parent-of', 'Sue',    'Bill'],
    ['gender',    'Sue',    'FeMale'],
    ['gender',    'Bill',   'Male'],
    ['parent-of', 'Sue',    'Mary'],
    ['gender',    'Alice',  'FeMale'],
    ['gender',    'Mary',   'FeMale'],
    ['parent-of', 'John',   'george'],
    ['gender',    'George', 'Male'],
    ['parent-of', 'John',   'Alice'],
    ['parent',    'Male',   'Father'],
    ['parent',    'FeMale', 'Mother']
]

# Function to find the gender of a person
fn genderOf person ->
    ('gender' :: {it == person} :: gender :: _)
    .matchlist(rels, { gender })
    .first()

# Function to find a person's parents
fn parentsOf person ->
    ('parent-of' :: {it == person} :: parent :: _)
    .matchlist(rels, { parent })

# Function to find a person's grandparents
fn grandParentsOf person ->
    parentsOf( person )
    .flatmap{ parentsOf(it) }

# Function to find a person't grandfather
fn grandFathersOf person ->
    grandParentsOf( person )
    .where{ genderOf(it) == 'Male' }
 
println("Bob's grandparents are " + grandParentsOf('Bob'))
println("Bob's grandfathers are " + grandFathersOf('Bob'))