View Source Version (Elixir v1.18.0)

Functions for parsing and matching versions against requirements.

A version is a string in a specific format or a Version generated after parsing via Version.parse/1.

Although Elixir projects are not required to follow SemVer, they must follow the format outlined on SemVer 2.0 schema.

Versions

In a nutshell, a version is represented by three numbers:

MAJOR.MINOR.PATCH

Pre-releases are supported by optionally appending a hyphen and a series of period-separated identifiers immediately following the patch version. Identifiers consist of only ASCII alphanumeric characters and hyphens ([0-9A-Za-z-]):

"1.0.0-alpha.3"

Build information can be added by appending a plus sign and a series of dot-separated identifiers immediately following the patch or pre-release version. Identifiers consist of only ASCII alphanumeric characters and hyphens ([0-9A-Za-z-]):

"1.0.0-alpha.3+20130417140000.amd64"

Requirements

Requirements allow you to specify which versions of a given dependency you are willing to work against. Requirements support the common comparison operators such as >, >=, <, <=, and == that work as one would expect, and additionally the special operator ~> described in detail further below.

# Only version 2.0.0
"== 2.0.0"

# Anything later than 2.0.0
"> 2.0.0"

Requirements also support and and or for complex conditions:

# 2.0.0 and later until 2.1.0
">= 2.0.0 and < 2.1.0"

Since the example above is such a common requirement, it can be expressed as:

"~> 2.0.0"

~> will never include pre-release versions of its upper bound, regardless of the usage of the :allow_pre option, or whether the operand is a pre-release version. It can also be used to set an upper bound on only the major version part. See the table below for ~> requirements and their corresponding translations.

`~>`	Translation
`~> 2.0.0`	`>= 2.0.0 and < 2.1.0`
`~> 2.1.2`	`>= 2.1.2 and < 2.2.0`
`~> 2.1.3-dev`	`>= 2.1.3-dev and < 2.2.0`
`~> 2.0`	`>= 2.0.0 and < 3.0.0`
`~> 2.1`	`>= 2.1.0 and < 3.0.0`

The requirement operand after the ~> is allowed to omit the patch version, allowing us to express ~> 2.1 or ~> 2.1-dev, something that wouldn't be allowed when using the common comparison operators.

When the :allow_pre option is set false in Version.match?/3, the requirement will not match a pre-release version unless the operand is a pre-release version. The default is to always allow pre-releases but note that in Hex :allow_pre is set to false. See the table below for examples.

Requirement	Version	`:allow_pre`	Matches
`~> 2.0`	`2.1.0`	`true` or `false`	`true`
`~> 2.0`	`3.0.0`	`true` or `false`	`false`
`~> 2.0.0`	`2.0.5`	`true` or `false`	`true`
`~> 2.0.0`	`2.1.0`	`true` or `false`	`false`
`~> 2.1.2`	`2.1.6-dev`	`true`	`true`
`~> 2.1.2`	`2.1.6-dev`	`false`	`false`
`~> 2.1-dev`	`2.2.0-dev`	`true` or `false`	`true`
`~> 2.1.2-dev`	`2.1.6-dev`	`true` or `false`	`true`
`>= 2.1.0`	`2.2.0-dev`	`true`	`true`
`>= 2.1.0`	`2.2.0-dev`	`false`	`false`
`>= 2.1.0-dev`	`2.2.6-dev`	`true` or `false`	`true`

Summary

Types

build()

major()

minor()

patch()

pre()

requirement()

t()

version()

Functions

%Version{}

The Version struct.

compare(version1, version2)

Compares two versions.

compile_requirement(requirement)

Compiles a requirement to an internal representation that may optimize matching.

match?(version, requirement, opts \\ [])

Checks if the given version matches the specification.

parse(string)

Parses a version string into a Version struct.

parse!(string)

Parses a version string into a Version.

parse_requirement(string)

Parses a version requirement string into a Version.Requirement struct.

parse_requirement!(string)

Parses a version requirement string into a Version.Requirement struct.

to_string(version)

Converts the given version to a string.

Types

build()

@type build() :: String.t() | nil

major()

@type major() :: non_neg_integer()

minor()

@type minor() :: non_neg_integer()

patch()

@type patch() :: non_neg_integer()

pre()

@type pre() :: [String.t() | non_neg_integer()]

requirement()

@type requirement() :: String.t() | Version.Requirement.t()

t()

@type t() :: %Version{
  build: build(),
  major: major(),
  minor: minor(),
  patch: patch(),
  pre: pre()
}

version()

@type version() :: String.t() | t()

Functions

%Version{}

(struct)

The Version struct.

It contains the fields :major, :minor, :patch, :pre, and :build according to SemVer 2.0, where :pre is a list.

You can read those fields but you should not create a new Version directly via the struct syntax. Instead use the functions in this module.

compare(version1, version2)

@spec compare(version(), version()) :: :gt | :eq | :lt

Compares two versions.

Returns :gt if the first version is greater than the second one, and :lt for vice versa. If the two versions are equal, :eq is returned.

Pre-releases are strictly less than their corresponding release versions.

Patch segments are compared lexicographically if they are alphanumeric, and numerically otherwise.

Build segments are ignored: if two versions differ only in their build segment they are considered to be equal.

Raises a Version.InvalidVersionError exception if any of the two given versions are not parsable. If given an already parsed version this function won't raise.

Examples

iex> Version.compare("2.0.1-alpha1", "2.0.0")
:gt

iex> Version.compare("1.0.0-beta", "1.0.0-rc1")
:lt

iex> Version.compare("1.0.0-10", "1.0.0-2")
:gt

iex> Version.compare("2.0.1+build0", "2.0.1")
:eq

iex> Version.compare("invalid", "2.0.1")
** (Version.InvalidVersionError) invalid version: "invalid"

compile_requirement(requirement)

@spec compile_requirement(Version.Requirement.t()) :: Version.Requirement.t()

Compiles a requirement to an internal representation that may optimize matching.

The internal representation is opaque.

match?(version, requirement, opts \\ [])

@spec match?(version(), requirement(), keyword()) :: boolean()

Checks if the given version matches the specification.

Returns true if version satisfies requirement, false otherwise. Raises a Version.InvalidRequirementError exception if requirement is not parsable, or a Version.InvalidVersionError exception if version is not parsable. If given an already parsed version and requirement this function won't raise.

Options

:allow_pre (boolean) - when false, pre-release versions will not match unless the operand is a pre-release version. Defaults to true. For examples, please refer to the table above under the "Requirements" section.

Examples

iex> Version.match?("2.0.0", "> 1.0.0")
true

iex> Version.match?("2.0.0", "== 1.0.0")
false

iex> Version.match?("2.1.6-dev", "~> 2.1.2")
true

iex> Version.match?("2.1.6-dev", "~> 2.1.2", allow_pre: false)
false

iex> Version.match?("foo", "== 1.0.0")
** (Version.InvalidVersionError) invalid version: "foo"

iex> Version.match?("2.0.0", "== == 1.0.0")
** (Version.InvalidRequirementError) invalid requirement: "== == 1.0.0"

parse(string)

@spec parse(String.t()) :: {:ok, t()} | :error

Parses a version string into a Version struct.

Examples

iex> Version.parse("2.0.1-alpha1")
{:ok, %Version{major: 2, minor: 0, patch: 1, pre: ["alpha1"]}}

iex> Version.parse("2.0-alpha1")
:error

parse!(string)

@spec parse!(String.t()) :: t()

Parses a version string into a Version.

If string is an invalid version, a Version.InvalidVersionError is raised.

Examples

iex> Version.parse!("2.0.1-alpha1")
%Version{major: 2, minor: 0, patch: 1, pre: ["alpha1"]}

iex> Version.parse!("2.0-alpha1")
** (Version.InvalidVersionError) invalid version: "2.0-alpha1"

parse_requirement(string)

@spec parse_requirement(String.t()) :: {:ok, Version.Requirement.t()} | :error

Parses a version requirement string into a Version.Requirement struct.

Examples

iex> {:ok, requirement} = Version.parse_requirement("== 2.0.1")
iex> requirement
Version.parse_requirement!("== 2.0.1")

iex> Version.parse_requirement("== == 2.0.1")
:error

parse_requirement!(string)

(since 1.8.0)

@spec parse_requirement!(String.t()) :: Version.Requirement.t()

Parses a version requirement string into a Version.Requirement struct.

If string is an invalid requirement, a Version.InvalidRequirementError is raised.

Examples

iex> Version.parse_requirement!("== 2.0.1")
Version.parse_requirement!("== 2.0.1")

iex> Version.parse_requirement!("== == 2.0.1")
** (Version.InvalidRequirementError) invalid requirement: "== == 2.0.1"

to_string(version)

(since 1.14.0)

@spec to_string(t()) :: String.t()

Converts the given version to a string.

Examples

iex> Version.to_string(%Version{major: 1, minor: 2, patch: 3})
"1.2.3"
iex> Version.to_string(Version.parse!("1.14.0-rc.0+build0"))
"1.14.0-rc.0+build0"