Sah::Examples - Example Sah schemas


This document describes version 0.05 of Sah::Examples (from Perl distribution Sah-Examples), released on 2017-05-22.


This distribution contains various examples of Sah schemas in its per-dist share dir.

This POD also contains examples of schemas.


The examples are written in JSON with Javascript-style comments (// comment).

Various simple examples

 // integer, optional

 // required integer

 // same thing
 ["int", {"req": 1}]

 // integer between 1 and 10
 ["int*", {"min": 1, "max": 10}]

 // same thing, the curly brace is optional (unless for advanced stuff)
 ["int*", "min", 1, "max", 10]

 // array of integers between 1 and 10
 ["array*", {"of": ['int*', "between": [1, 10]]}]

 // a byte (let's assign it to a new type 'byte')
 ["int", {"between": [0,255]}]

 // a byte that's divisible by 3
 ["byte", {"div_by": 3}]

 // a byte that's divisible by 3 *and* 5
 ["byte", {'div_by&": [3, 5]}]

 // a byte that's divisible by 3 *or* 5
 ["byte", {"div_by|": [3, 5]}]

 // a byte that's *in*divisible by 3
 ["byte", {"!div_by": 3}]

Type: array

 // minimum number of elements
 ["array*", {"min_len": 1}]

 // maximum number of elements
 ["array*", {"max_len": 10}]

Type: hash

 // hash must only contain keys a, b, or c
 // Valid: {}, {"a": 1}, {"a": 1, "b": "x", "c": [1]}
 // Invalid: {"d": 1} (unknown key), {"a": 1.1} (key 'a' is not int)
 ["hash", {"keys": {"a": "int", "b": "str*", "c": ["array", "min_len", 1]}}]

 // hash can contain a, b, c or other keys
 // Valid: {"d": 1}, {"d": null}
 // Invalid: {"a": 1.1} (key 'a' is not int)
 ["hash", {"keys": {"a": "int", "b": "str*", "c": ["array", "min_len", 1]}, "keys.restrict": 0}]

 // hash must contain keys a, b; can contain also c but no other keys
 ["hash", {"req_keys": ["a","b"], "keys": {"a": "int", "b": "str*", "c": ["array", "min_len", 1]}}]

 // hash must contain keys a, b; can contain c or other keys
 ["hash", {"req_keys": ["a","b"], "keys": {"a": "int", "b": "str*", "c": ["array", "min_len", 1]}, "keys.restrict": 0}]

Clause attribute

Coercion rule

Explicitly enable rule(s) that is (are) not enabled by default:

 // allow input as comma-separated string, e.g. "1,20,3,4"
 ["array", {"of": "int", "x.perl.coerce_rules": ["str_comma_sep"]}]

Explicitly disable rule(s) that is (are) enabled by default:

 // don't allow duration to be coerced from integer (number of seconds)
 ["duration", {"x.perl.coerce_rules": ["!float_secs"]}]




 // an address hash (let's assign it to a new type called 'address')
 ["hash", {
     // recognized keys
     "keys": {
         "line1":    ["str*", {"max_len": 80}],
         "line2":    ["str*", {"max_len": 80}],
         "city":     ["str*", {"max_len": 60}],
         "province": ["str*", {"max_len": 60}],
         "postcode": ["str*", {"len_between": [4, 15], "match": "^[\w-]{4,15}$"}],
         "country":  ["str*", {"len": 2, "match": "^[A-Z][A-Z]$"}]
     // keys that must exist in data
     "req_keys": ["line1", "city", "province", "postcode", "country"]

  // a US address, let's base it on 'address' but change 'postcode' to
  // 'zipcode'. also, require country to be set to 'US'
  ["address", {
      "merge.subtract.keys": {"postcode": null},
      "merge.normal.keys": {
          "zipcode": ["str*", "len", 5, "match", "^\d{5}$"],
          "country": ["str*", "is", "US"]
      "merge.subtract.req_keys": ["postcode"],
      "merge.add.req_keys": ["zipcode"]


Please visit the project's homepage at


Source repository is at


Please report any bugs or feature requests on the bugtracker website

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.


Sah specification, which contains a spectest in its per-dist share dir.

Data::Sah, Perl implementation for Sah.

Data::Sah::Coerce for more information about coercion.

Various Sah::Schema::* modules (in Sah::Schema::* or Sah::Schemas::* distributions) which contain schemas in Perl modules.


perlancar <>


This software is copyright (c) 2017, 2015 by

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.