NAME

Sah::Type - Standard types

VERSION

This document describes version 0.9.51 of Sah::Type (from Perl distribution Sah), released on 2022-10-21.

DESCRIPTION

This document specifies Sah standard types.

TYPE: undef

This type does not have any clauses. The only value it knows is the undefined value (like undef in Perl, or null in PHP).

ROLE: BaseType

This is the base type role, all Sah types (except undef) must implement this role.

Clauses

The list below is ordered by priority, from highest to lowest.

defhash_v

Value: float.

Priority: 0 (checked first before everything else).

Category: metadata.

From DefHash. Normally there is no need to set this.

v

Value: float, default: 1.

Priority: 0 (checked first before everything else).

Category: metadata.

From DefHash. Specify Sah version. Should be 1 at the moment.

schema_v

Value: float, default 1.

Priority: 0 (checked first before everything else).

Category: metadata.

Specify schema version. By default assumed to be 1 if not set.

base_v

Value: float, default 1.

Priority: 0 (checked first before everything else).

Category: metadata.

Specify base schema version. By default assumed to be 1 if not set. Using a base schema with a different value will fail. Can be used to force child schemas to update whenever we change our schema. For example:

 // schema: vocal
 ["str", {"in": ["a", "e", "i", "o", "u"]}]

 // schema: consonant, defined in terms of "vocal", by
 ["vocal", {"match": "\\A[a-z]\\z", "in.op": "not"}]

However, if vocal changes its implementation or structure to:

 // the new vocal
 ["str", {"match": "\\A[aeiou]\\z"}]

then consonant will silently break because of clash (overriding) in the match clause. To force consonant to fail (so its author can update it, should the authors of vocal and consonant are two different persons):

 // the new vocal
 ["str", {"schema_v": 2, "match": "\\A[aeiou]\\z"}]

Since vocal's schema_v is now 2, it is not the same as 1 (which is implied by consonant, having the default value of that of "base_v"). consonant's author might then update its own implementation to match vocal:

 // the adjusted consonant
 ["vocal", {"base_v":2, "clset":{"match":"\\A[a-z]\\z"}, "match.op":"not"}]

Notice the matching of consonant's "base_v" against vocal's "schema_v". consonant might also add its own "schema_v":2 so other schemas depending on it are forced to adjust, if needed.

c

Value: any.

Priority: 0 (checked first before anything else).

Category: metadata

Used to store compiler-specific options in its attributes. Example:

 "c.perl.use_defined_or": 0

ok

Value: true.

Return value: true (always succeeds).

Priority: 1 (very high). This is processed before all other clauses.

Category: constraint.

Will do nothing. This clause is just a convenience if you want to do nothing (or perhaps just use the attributes of this clause to do things). It is the default in the else section of the "if" clause.

To force failure, you can use "!ok": true.

default

Value: any.

Priority: 1 (very high). This is processed before all other clauses except "ok".

Category: default.

Attributes specific to this clause: temp (bool, default 0, if set to true then default value will only be used during validation and at the end data will not use this value).

Supply a default value.

Example: Given schema ["int", {"req": 1}] an undef data is invalid, but given schema ["int", {"req": 1, "default": 3}] an undef data is valid because it will be given default value first.

default_lang

Value: str (locale code)d default en_US.

Priority: 2 (very high), after "default".

Category: metadata.

From DefHash. Set default language for this schema. Language-dependant attribute values (e.g. "summary", "description") will be assumed to be in the default language.

name

Value: str or [str, str].

Priority: 2 (very high), after "default".

Category: metadata.

From DefHash. A short noun (usually one or two words, without any formatting) to name the schema, useful for compiler that transform the schema to human description text.

Aside from string, it can also be a two-element string to set the singular and plural form of the noun.

To store translations, you can use DefHash's alt.lang.* clause attributes (or its shortcut form using (LANG) suffix).

Example:

 ["int", {
     "min": 0,
     "name": ["positive integer", "positive integers"],
     "name(id_ID)": "bilangan positif"
 }]

See also: "summary", "description", "tags".

caption

Value: str.

Priority: 2 (very high), after "default".

From DefHash.

summary

Value: str.

Priority: 2 (very high), after "default".

Category: metadata.

From DefHash. A one-line text (about 72 characters maximum, without any formatting) to describe the schema. This is useful, e.g. for manually describing a schema instead of using the human compiler. It can also be used in form field labels.

To store translations, you can use DefHash's alt.lang.* clause attributes (or its shortcut form using (LANG) suffix).

Example:

 // definition for 'single_dice_throw' schema/type
 ["int", {
     "req": 1,
     "summary":
         "A number representing result of single dice throw (1-6)",
     "summary(id_ID)":
         "Bilangan yang menyatakan hasil lempar sebuah dadu (1-6)",
     "between": [1, 6]
 }]

Without the summary, using a compiler to human text the above schema might be output as the standard, more boring "Integer, value between 1 and 6".

See also: "name", "description", "tags".

description

Value: str.

Priority: 2 (very high), after "default".

Category: metadata.

From DefHash. A longer text (a paragraph or more) to describe the schema, useful e.g. for help/usage text. Text should be in Markdown format.

To store translations, you can use DefHash's alt.lang.* clause attributes (or its shortcut form using (LANG) suffix).

Example (using Perl syntax because it supports heredoc):

 ["array", {
     name        => 'http_headers',
     description => <<EOT,
 HTTP headers should be specified as an array of 2-element arrays (pairs). Each
 pair should contain header name in the first element (all lowercase, *-*
 written as *_*) and header value in the second element.

 Example:

     [["content_type","text/html"], ["accept","text/html"], ["accept","*/*"]]

 EOT
     req         => 1,
     of          => 'http_header',
  },
  {}]

See also: "name", "summary", "tags".

tags

Value: array of str.

Priority: 2 (very high), after "default".

Category: metadata.

From DefHash. A list of tags, can be used to categorize schemas.

See also: "name", "summary", "description".

req

Value: bool.

Priority: 3 (very high), executed after "default".

Category: constraint.

If set to 1, require that data be defined. Otherwise, allow data to be undef (the default behaviour).

By default, undef will pass even elaborate schema, e.g. ["int", {"min": 0, "max": 10, "div_by": 3}] will still pass an undef. However, undef will not pass ["int": {"req": 1}].

This behaviour is much like NULLs in SQL: we *can't* (in)validate something that is unknown/unset.

See also: "forbidden"

forbidden

Value: bool.

Priority: 3 (very high), executed after "default".

Category: constraint.

This is the opposite of "req", requiring that data be not defined (i.e. undef).

Given schema ["int", {"forbidden": 1}], a non-undef value will fail. Another example: the schema ["int", {"req": 1, "forbidden": 1}] will always fail due to conflicting clauses.

See also: "req"

prefilters

Value: array of (filter rule name)s, or ([filter rule name, argument hash]).

Priority: 10 (high). Run after "default" and "req"/"forbidden".

Category: filter.

Attributes specific to this clause: temp (bool, default 0, if set to true then prefiltered value will only be used during validation and at the end of the clause set data will not use this value).

clause

Value: 2-element array [CLNAME, CLVAL].

Return value: clause return value.

Priority: 50 (normal)

Category: constraint.

Evaluate a clause. Example:

 ["int", "clause", ["div_by", 2]] // equivalent to ["int", "div_by", 2]

This clause is useful when combined with the .op attribute. Example:

 ["int", "clause|", [["div_by", 2], ["xmin", 10]]]
 // equivalent to:
 // ["int", "clause", [["div_by", 2], ["xmin", 10]], "clause.op", "or"]

The above schema says that the integer needs to be divisible by 2 or larger than 10.

clset

Value: hash.

Return value: int (number of successful clauses + 1) on success, false on failure.

Priority: 50 (normal)

Category: constraint.

Evaluate a clause set. Note that return value adds 1 to the number of successful clauses to avoid returning 0 (evaluates to false). And it will only be returned if clause is successful. Otherwise false (0) will be returned. Example:

 // require that data is between 1 and 10.
 // equivalent to ["int", "min", 1, "max", 10]
 ["int", "clset", {"min": 1, "max": 10}]

 // require that either data is between 1 and 10, or 90 and 100
 ["int", "clset|", [{"min": 1, "max": 10}, {"min": 90, "max": 100}]]

See also: "clause".

check

Value: expression string.

Return value: result of evaluated expression

Priority: 50 (normal)

Category: constraint.

Evaluate expression, which must evaluate to a true value for this clause to succeed. Examples:

 // require that string is a palindrome, using a Sah function
 ["str", "check", "is_palindrome($_)"]

 // require that the *length of* string is a prime number
 ["str", "check", "is_prime(len($_))"]

prop

Value: 2-element str [PROP, SCHEMA].

Return value: bool

Priority: 50 (normal)

Category: constraint

Validate property against a schema. Example:

 // require that the *length of* string is divisible by 2
 ["str", "prop", ["len", ["int", "div_by", 2]]]

See also: "check_prop"

check_prop

Value: 2-element str [PROP, SCHEMA].

Return value: result of evaluated expression

Priority: 50 (normal)

Category: constraint

Just like "check", but instead of checking data itself, check property PROP. Example:

 // require that the *length of* string is a prime number
 ["str", "check_prop", ["len", "is_prime($_)"]]

 // check that the email's Subject header is a palindrome
 ["email", "check_prop", [["headers", "subject"], "is_palindrome($_)"]]

See also: "prop"

if

Value:

 [COND, THEN] -> any
 [COND, THEN, ELSE] -> any

Return value: if condition is true, then the THEN result, otherwise the ELSE result.

Priority: 50 (normal)

Category: constraint.

A generic condition clause. COND, THEN, and ELSE are either boolean values, expressions (if they are string) or a clause set (if they are hash) or a schema (if they are array). COND is evaluated, if the result is true then THEN is evaluated, otherwise ELSE is evaluated. ELSE is optional.

Examples:

 // forbid the string to be lowercase
 "if": [{"match": "^[a-z]$"}, false]

 // if string is lowercase, it must be a palindrome
 "if": [{"match": "^[a-z]$"}, "is_palindrome($_)"]

 // if string is lowercase, it must be a palindrome, otherwise it must be longer
 // than 3 characters.
 "if": [{"match": "^[a-z]$"}, "is_palindrome($_)", "len($_) > 3"]

 // require the length of the string to be an even number
 "if": [{"prop": ["len", ["int", "div_by", 2]]}, true}

 // if string is a palindrome, then require it to have length > 5
 "if": [{"check": "is_palindrome($_)"}, ["len", ["int", "xmin": 5]]]

Note that you have to write schema in array form instead of string form, to avoid ambiguity with expression:

 // parsed as expression, wrong!
 "if": ["int", true]

 // correct
 "if": [["int"], true]

postfilters

Value: array of (filter rule name)s, or ([filter rule name, argument hash]).

Priority: 90 (very low). Run after all other clauses.

Category: filter.

From here on, the data will be permanently set to the postfiltered value.

examples

Value: array of (non-hash values|defhash)

Priority: 99 (informational)

Category: metadata.

A list of sample valid values. Can be used, e.g. for documentation, testing, or completion. Each element is sample value, except when value is a hash then it is assumed as a defhash (with the actual value in the value property). So if your sample value happens to be a hash like {}, it has to be specified as {"value":{}}.

Note that this clause is informational only and does not require the value to be in one of the specified examples (use "in" clause for this purpose).

See also: "invalid_examples", "in".

invalid_examples

Value: array of (non-hash values|defhash)

Priority: 99 (informational)

Category: metadata.

This is the counterpart of "examples", containing examples of invalid values.

See also: "examples".

ROLE: Comparable

This is the comparable type role. All types which have comparable values must implement this role. Most types implement this role, including str, all number types, etc.

Clauses

in

Value: array of any values.

Priority: 50 (normal)

Category: constraint

Require that the data be one of the specified choices.

Examples:

 ["int", {"in": [1, 2, 3, 4, 5, 6]}] // single dice throw value
 ["str", {"!in": ["root", "admin", "administrator"]}] // forbidden usernames

To provide sample valid values that are not binding, use the "examples" clause.

See also: "examples", "match" (for type str), "has" (for HasElems types).

is

Value: any.

Priority: 50 (normal)

Category: constraint

Require that the data is the same as VALUE. Will perform a numeric comparison for numeric types, or stringwise for string types, or deep comparison for deep structures.

Examples:

 ["int", {"is": 3}]
 ["int", {"is&": [1, 2, 3, 4, 5, 6]}] // effectively the same as 'in'

ROLE: HasElems

This is the role for types that have the notion of elements/length. It provides clauses like "max_len", "len", "len_between", "each_elem", etc. It is used by array, hash, and also str.

Properties

len (HasElems property)

Number.

elems (HasElems property)

Array.

indices (HasElems property)

Array.

Clauses

max_len

Value: uint.

Priority: 50 (normal)

Category: constraint

Requires that the data have at most the specified number of elements.

Example:

 ["str", {"req": 1, "max_len": 10}] // string with at most 10 characters

min_len

Value: uint.

Priority: 50 (normal)

Category: constraint

Requires that the data have at least the specified number of elements.

Example:

 ["array", {"min_len": 1}] // define an array with at least one element

len_between

Value: 2-element array ([NUM_MIN, NUM_MAX])

Priority: 50 (normal)

Category: constraint

A convenience clause that combines "min_len" and "max_len".

Example, the two schemas below are equivalent:

 ["str", {"len_between": [1, 10]}]
 ["str", {"min_len": 1, "max_len": 10}]

len

Value: uint.

Priority: 50 (normal)

Category: constraint

Requires that the data have exactly NUM elements.

has

Value: any.

Priority: 50 (normal)

Category: constraint

Requires that the data contains the element. This is the counterpart of the "in" clause.

Examples:

 // requires that array has element x
 ["array", {"has": "x"}]

 // requires that array has elements 'x', 'y', and 'z'
 ["array", {"has&": ["x", "y", "z"]}]

 // requires that string does not have character 'x'
 ["str", {"!has": "x"}]

uniq

Value: bool.

If set to 1, require that the element values be unique (like in a set). If set to 0, require that there are duplicates in the elements. For example, given this schema:

 ["array", "uniq", true]

this data passes: [1, 2, 3] but this one does not: [1, 2, 1].

each_elem

Value: schema.

Priority: 50 (normal)

Category: constraint, looping

Requires that every element of data validate to the specified schema. The first element that fails the schema will terminate the loop.

Examples:

 ["array", {"each_elem": "int"}]
 ["array", {"of": "int"}] // same thing, "of" is the same as "each_elem"

The above specifies an array of integers.

 ["hash", {"each_elem": ["str", {"match": "^[A-Za-z0-9]+$" }]}]

The above specifies hash with alphanumeric-only values.

check_each_elem

Value: expression string.

Priority: 50 (normal)

Category: constraint, looping

Just like "each_elem" but instead of using schema, each element is tested using expression.

each_index

Value: schema.

Priority: 50 (normal)

Category: constraint, looping

Like "each_elem" but iterates over the indices. For type like array, this is 0, 1, ... N. For hash, this is the keys of hash.

check_each_index

Value: expression string.

Priority: 50 (normal)

Category: constraint, looping

Like "each_index" but instead of using schema, each index is tested using expression.

exists

Value: schema.

Priority: 50 (normal)

Category: constraint, looping

Test that there is at least one element of data that validates to the schema. That element is returned. Be careful to not return element which has the value which evaluates to false.

check_exists

Value: expression string.

Priority: 50 (normal)

Category: constraint, looping

Just like "exists" but instead of using schema, each element is tested using expression.

ROLE: Sortable

This is the type role for sortable types. It provides clauses like "min", "max", and "between". It is used by many types, for example str, all numeric types, etc.

Clauses

min

Value: any.

Require that the value is not less than some specified minimum (equivalent in intention to the Perl string ge operator, or the numeric >= operator).

Example:

 ["int", "min", 0] // specify positive numbers

xmin

Value: any.

Require that the value is not less nor equal than some specified minimum (equivalent in intention to the Perl string gt operator, or the numeric > operator). The x prefix is for "exclusive".

max

Value: any.

Require that the value is less or equal than some specified maximum (equivalent in intention to the Perl string le operator, or the numeric <= operator).

xmax

Value: any.

Require that the value is less than some specified maximum (equivalent in intention to the Perl string lt operator, or the numeric < operator). The x prefix is for "exclusive".

between

Value: 2-element string ([ANY_MIN, ANY_MAX])

A convenient clause to combine "min" and "max".

Example, the following schemas are equivalent:

 ["float", {"between": [0.0, 1.5]}]
 ["float", {"min": 0.0, "max": 1.5}]

xbetween

Value: 2-element string ([ANY_MIN, ANY_MAX])

A convenient clause to combine "xmin" and "xmax".

TYPE: buf

buf stores binary data. Elements of buf data are bytes. It is derived from str.

TYPE: num

num stores numbers. This type assumes the Comparable and Sortable roles.

TYPE: float

float stores real (floating-point) numbers. This type is derived from num.

Clauses

is_nan

Value: bool.

If true, require that number is a NaN (e.g. "NaN" or "-NaN" in Perl). If false, forbid that the number is a NaN.

is_inf

Value: bool.

If true, require that number is a positive or negative infinity (e.g. "Inf" or "-Infinity" in Perl). If false, forbid that the number is an infinity (which can mean a finite number or a NaN).

is_pos_inf

Value: bool.

If true, require that number is a positive infinity (e.g. "Inf" or "+Infinity" in Perl). If false, forbid that number is a positive infinity (which can mean a finite number, negative infinity, or a NaN).

is_neg_inf

Value: bool.

If true, require that number is a negative infinity (e.g. "-Inf" or "-Infinity" in Perl). If false, forbid that number is a negative infinity (which can mean a finite number, positive infinity, or a NaN).

TYPE: int

int stores integers. This type is derived from num.

Clauses

mod

Value: 2-element array of ints ([INT1, INT2]).

Require that (data mod INT1) equals INT2. For example, "mod": [2, 1] effectively specifies odd numbers.

div_by

Value: int.

Require that data is divisible by the specified number. This is effectively just a shortcut for "mod": [INT, 0].

Example: Given schema ["int", {"div_by": 2}], null, 0, 2, 4, and 6 are valid but 1, 3, 5 are not.

TYPE: str

str stores strings (text). This type assumes the Comparable, Sortable, and HasElems roles (the elements are individual characters, the indices are integers from 0 to (length of string)-1). Default encoding is utf8.

Clauses

encoding

Value: str, default utf8.

Specify encoding. Currently the only supported value is utf8.

match

Value: string (regex) or hash of regexes (REGEX|{COMPILER=>REGEX, ...})

Require that string match the specified regular expression.

Since regular expressions might not be 100% compatible from language to language, instead of avoiding the use of regex entirely, you can specify different regex for each target language, e.g.:

 ["str", {"match": {
   "js":     "...",
   "perl":   "...",
   "python": "..."
 }}]

To match against multiple regexes:

 // string must match a, b, and c
 ["str", {"match&": ["a", "b", "c"]}]

 // string must match either a or b or c
 ["str", {"match|": ["a", "b", "c"]}

 // string must NOT match a
 ["str", {"!match": "a"}]

 // string must NOT match a nor b nor c (i.e. must match none of those)
 ["str", {"match": [a, b, c], "match.op": "none"}]

is_re

Value: bool.

If value is true, require that the string be a valid regular expression string. If value is false, require that the string not be a valid regular expression string.

TYPE: cistr

Just like str, but comparison between values will be done case-insensitively.

TYPE: bool

Boolean type. This type assumes the Comparable and Sortable roles.

Clauses

is_true

Value: bool.

Require that value is true. This is a more portable way than comparing to a value using "is". To require that value is false, set this clause to a false value. Alternatively you can also use "!is_true": 1.

TYPE: array

Array type. This type assumes the Comparable and HasElems roles (the elements are indexed by integers starting from 0).

Clauses

elems

Value: array of schema.

Attributes: create_default (bool, default: 1).

Specify schemas for each element of the array. Example:

 ["array", "elems", ["int*", "float"]]

Valid values include [1], [1, undef], [1, 1.1], [1, 1.1, "foo"]. Invalid values include [] (first element is a required int), [1, "foo"] (second element does not validate).

If there are not enough elements in the data, they will be assumed to be null (undefined value). Extra elements in the data are ignored.

The .create_default attribute regulates whether missing elements should be set with default values if they do not exist in the data. Example:

 ["array", "elems", ["int*", ["float", "default", 2]]]

In the last example, [1] will become [1, 2] after validation. However with:

 ["array",
     "elems", ["int*", ["float", "default", 2]],
     "elems.create_default", 0]

[1] will still become [1] after validation. In both cases, [1, undef] will become [1, 2].

of

Value: schema.

This is just an alias to "each_elem".

TYPE: hash

Hash (a.k.a. dictionary) type. This type assumes the "ROLE: Comparable" in Comparable and HasElems roles (the elements are hash values, the indices are hash keys).

Properties

keys (hash property)

Value: array.

Alias for HasElems's "indices".

values (hash property)

Value: array.

Alias for HasElems's "elems".

Clauses

keys

Value: hash.

Attributes: restrict (bool, default: 1), create_default (bool, default: 1).

Specify schema for specific pair value. Also, by default, restrict keys of hash to the list specified in this clause, except if the .restrict attribute is set to false. Example:

 ["hash*",
     "keys", {
         "name": "str",
         "address": ["any", "of", ["str", ["array", "of", "str"]]],
         "email": "email_address"
     },
 ]

The above schema requires data to be a hash with keys name, address, email. None of the keys are required to be present (use "req_keys" for that), but other keys are not allowed.

Another example:

 ["hash",
     "keys", {"a": "int", "b": "str", "c": "float"},
     "keys.restrict", 0
 ]

The above schema specifies a hash with definition for the value of its a, b, and c keys. But other keys like d are allowed since the "keys" clause is set to not restrict keys.

The .create_default attribute regulates whether keys should be created with default values if they do not exist in the data. For example:

 ["hash", "keys": {"a": "int", "b": ["int", "default": 2]}]

Given data {}, by default it will be given defaults so it becomes {"b": 2}. a is not created because it does not have a default value. However, if .create_default is set to false:

 ["hash",
     "keys", {"a": "int", "b": ["int", "default": 2]},
     "keys.create_default", 0
 ]

then {} will still become {} after validation. In both cases, {"b": null} will still become {"b": 2}.

re_keys

Value: hash

Attributes: restrict (bool, default: 1)

Just like keys, but specifies schemas for keys which match regexes. Example:

 ["hash", "re_keys", {"^[A-Za-z]": "str", "^[0-9]": "int"}]

The above schema specifies that for keys which begin with a letter the values must be strings, and for keys which begin with a digit the values must be integers. These hashes validate: {}, {"a": "x", "b": 1, "1": 1}. These hashes do not validate: {"1": "x"}, {"#": "x"} (key does not match any keys in "re_keys").

req_keys

Value: array

Specify which keys are required to be exist. Note that the values for those keys are not required to be defined (use "keys" for that). Example:

 ["hash", "req_keys", ["a", "b"]]

The above schema specifies that hash needs to have some keys, but the value can be null. This hash will validate: {"a": 1, "b": null}. However, given this schema:

 ["hash", "req_keys", ["a", "b"], "keys", {"a": "int", "b": "int*"}]

the previous hash will not validate since the value for b is required.

Note: you can also use the "keys" property to express the same thing, but "req_keys" is more convenient:

 ["hash", "prop", ["keys", ["array", "has&", ["a", "b"]]]]

See also: "allowed_keys", "forbidden_keys".

allowed_keys

Value: array

Specify which keys are allowed (can exist). Unlike "req_keys", keys specified in the value need not exist. Example:

 ["hash", "allowed_keys", ["a", "b"]]

Then hashes {}, {"a":1}, {"a":1,"b":2} all pass, but {"a":1,"c":3} fails because it contains keys outside the allowed list.

Note: you can also use the "keys" property to express the same thing, but "allowed_keys" is more convenient:

 ["hash", "prop", ["keys", ["array", "each_elem", ["str", "in", ["a", "b"]]]]]

See also: "req_keys", "forbidden_keys".

allowed_keys_re

Value: regex

Like "allowed_keys" but using regular expression.

forbidden_keys

Value: array

Specify which keys are forbidden (must not exist). Example:

 ["hash", "forbidden_keys", ["a", "b"]]

Then hashes {}, {"c":1} all pass, but {"a":1,"c":3} fails because it contains keys in the forbidden list.

Note: you can also use the keys property to express the same thing, but "forbidden_keys" is more convenient:

 ["hash", "prop", ["keys", ["array", "each_elem", ["str", "!in", ["a", "b"]]]]]

See also: "req_keys", "allowed_keys".

forbidden_keys_re

Value: regex

Like "forbidden_keys" but using regular expression.

each_key

Alias for "each_index".

each_value

Alias for "each_elem".

check_each_key

Alias for "check_each_index".

check_each_value

Alias for "check_each_elem".

choose_one_key

Value: array of str.

Specify that hash contains at most one out of a list of key names. Example:

 ["hash", "choose_one_key", ["exclude", "exclude_from"]]

Hash can contain either "exclude" or "exclude_from" but not both.

choose_one

Alias for "choose_one_key".

choose_all_keys

Value: array of str.

Specify that if hash contains any one of keys in a given list of key names, then hash must contain all of those keys. Example:

 ["hash", "choose_all_keys", ["password", "confirmation"]]

When hash contains "password", it must also contain "confirmation". And vice versa.

choose_all

Alias for "choose_all_keys".

choose_some_keys

Value: 3-element array ([MIN, MAX, KEYS]).

Require that hash has between MIN and MAX of keys in KEYS.

req_one_key

Value: array of str.

Specify that only exactly one key is required to exist. Example:

 ["hash", "req_one_key", ["input_value", "input_file"]] // either specify input value directly, or specify path to file that contains the value

When the two keys both exist, the clause fails.

req_one

Alias for "req_one_key".

req_all_keys

Alias for "req_keys".

req_all

Alias for "req_keys".

req_some_keys

Value: 3-element array ([MIN, MAX, KEYS])

Specify that between MIN and MAX of keys in KEYS are required.

req_some

Alias for "req_some_keys".

dep_any

Value: 2-element array ([ STR|ARRAY[STR], ARRAY[STR] ])

Specify that the first argument (either a string containing a key name, or a list of key names) can only exist when one of the keys given in the second argument exists. Example:

 ["hash", "dep_any", ["postcode", ["address"]]]

The "postcode" key can only be specified if "address" key exists.

Another example:

 ["hash", "dep_any", ["input_format", ["input_value", "input_file"]]

If "input_value" or "input_file" exists, then "input_format" is allowed to be specified.

Yet another example:

 ["hash", "dep_any", [["input_format", "input_is_yaml", "input_is_json"], ["input_value", "input_file"]]

If either "input_value" or "input_file" exists, then one of "input_format", "input_is_yaml", "input_is_json" is allowed to be specified.

dep_all

Value: 2-element array ([ STR|ARRAY[STR], ARRAY[STR] ])

Specify that the first argument (either a string containing a key name, or a list of key names) can only exist when all of the keys given in the second argument exist. Example:

 ["hash", "dep_all", ["postcode", ["address"]]]

In the above example, you can also use "dep_any" clause for the same effect since there is only one key to depend on. Another example:

 ["hash", "dep_all", ["postcode", ["address", "city"]]

In the above example, "postcode" can only be specified when both "address" and "city" exist. Yet another example:

req_dep_any

Value: 2-element array ([ STR|ARRAY[STR], ARRAY[STR] ])

Specify that the first argument (either a string containing a key name, or a list of key names) is required when one of the keys given in the second argument exist.

req_dep_all

Value: 2-element array ([ STR|ARRAY[STR], ARRAY[STR] ])

Specify that the first argument (either a string containing a key name, or a list of key names) is required when all of the keys given in the second argument exist.

TYPE: any

A type to specify alternate schemas, or a type that allows any value.

Clauses

of (any)

Value: array of schemas

Specify the schema(s) where the value will need to be valid to at least one of them.

TYPE: all

A type to specify co-schemas (all schemas that must be validated to value).

Clauses

of (all)

Value: array of schemas

Specify the schema(s) where the value will need to be valid to all of them.

TYPE: obj

Object.

Properties

meths (obj property)

attrs (obj property)

Clauses

can

Value: str.

isa

Value: str.

TYPE: date (not yet specified)

TYPE: datenotime (not yet specified)

TYPE: datetime (not yet specified)

TYPE: duration (not yet specified)

TYPE: timeofday (not yet specified)

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Sah.

SOURCE

Source repository is at https://github.com/perlancar/perl-Sah.

SEE ALSO

DefHash

Sah

AUTHOR

perlancar <perlancar@cpan.org>

CONTRIBUTING

To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:

 % prove -l

If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.

COPYRIGHT AND LICENSE

This software is copyright (c) 2022, 2020, 2019, 2017, 2016, 2015, 2014, 2013, 2012 by perlancar <perlancar@cpan.org>.

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

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Sah

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.