countries.yml

--- !yamlscript/v0

ns: schemays

defn validate(val checks err='Validation error'):
  checks =: checks:seqable?.if(checks [checks])
  mapv _ checks:
    fn(check):
      when-not check(val):
        die: err
  =>: val

defn mktype(name fns):
  intern NS name:symbol:
    fn(val):
      each f fns:
        f(val) || die("failed $name")
      =>: val

defn mklist(name check):
  intern NS name:symbol:
    fn(vals):
      if vals:coll?:
        each val vals:
          check: val
        else:
          die: "Failed $name. Not a list: $val"

defn mktypes(specs):
  each spec specs:
    key val =: spec:first
    foo =: val:first
    if foo:map? && (foo:keys.0 == '-list'):
      then:
        mklist key: foo.get('-list')
      else:
        mktype key: val

--- !yamlscript/v0

schemays/mktypes::
- non-empty-string?:
  - ! string?
  - ! comp(not empty?)
- positive-int?:
  - ! int?
  - ! gt(0)
- positive-num?:
  - ! number?
  - ! gt(0)

--- !yamlscript/v0

declare: country

schemays/mktypes::
- country:
  - ! \(_.name:non-empty-string?)
  - ! \(_.area:positive-num?)
  - ! \(_.population:positive-int?)

schemays/mktypes::
- countries:
  - -list:: country

--- !yamlscript/v0/data

countries: !:countries
# - type: Triangle
#   sides: [3,4,5]

- name: foo
  population: 1000
  area: 42334.11
  climate: Foggy wet.

- name: bar
  population: 2000
  area: 44242
  incomeTax: 55

- name: baz
  population: 100
  area: 1234.432
  planet: mars