.. index:: single: url(Representation) .. _url/1:

.. rst-class:: right

object

url(Representation)

• Representation - URL and is components representation. Valid values are atom, codes, and chars. URL validating, parsing, and normalizing predicates following RFC3986 nomenclature.

  | Availability: | logtalk_load(url(loader))

  | Author: Paulo Moura | Version: 2:0:0 | Date: 2026-05-22

  | Compilation flags: | static, context_switching_calls

  | Uses: | :ref:`list <list/0>`

  | Remarks: | (none)

  | Inherited public predicates: | (none)

  .. contents:: :local: :backlinks: top

Public predicates

.. index:: valid/1 .. _url/1::valid/1:

valid/1 ^^^^^^^^^^^

True iff the argument is a valid URL, including optional query and fragment components.

| Compilation flags: | static

| Template: | valid(URL) | Mode and number of proofs: | valid(++text) - zero_or_one

---

.. index:: parse/2 .. _url/1::parse/2:

parse/2 ^^^^^^^^^^^

Parses a URL into a list of its components: [scheme(Scheme), authority(Authority), path(Path), query(Query), fragment(Fragment)]. Fails if the URL is invalid and cannot be parsed.

| Compilation flags: | static

| Template: | parse(URL,Components) | Mode and number of proofs: | parse(++text,-list(compound)) - zero_or_one

---

.. index:: generate/2 .. _url/1::generate/2:

generate/2 ^^^^^^^^^^^^^^

Generates a normalized URL or RFC3986 relative reference from a list of components. Component lists headed by scheme/1 generate absolute URLs; lists without scheme/1 generate relative references.

| Compilation flags: | static

| Template: | generate(Components,URL) | Mode and number of proofs: | generate(++list(compound),-text) - zero_or_one

---

.. index:: parse/3 .. _url/1::parse/3:

parse/3 ^^^^^^^^^^^

Parses a URL or RFC3986 relative reference into a list of its components and classifies it as one of url, network_path, absolute_path, relative_path, query, or fragment.

| Compilation flags: | static

| Template: | parse(Reference,Components,Kind) | Mode and number of proofs: | parse(++text,-list(compound),-atom) - zero_or_one

---

.. index:: reference_kind/2 .. _url/1::reference_kind/2:

reference_kind/2 ^^^^^^^^^^^^^^^^^^^^

Classifies a valid reference as one of url, network_path, absolute_path, relative_path, query, or fragment.

| Compilation flags: | static

| Template: | reference_kind(Reference,Kind) | Mode and number of proofs: | reference_kind(++text,-atom) - zero_or_one

---

.. index:: equivalent/2 .. _url/1::equivalent/2:

equivalent/2 ^^^^^^^^^^^^^^^^

True iff both arguments normalize to the same textual representation under the library normalization rules.

| Compilation flags: | static

| Template: | equivalent(Reference1,Reference2) | Mode and number of proofs: | equivalent(++text,++text) - zero_or_one

---

.. index:: relativize/3 .. _url/1::relativize/3:

relativize/3 ^^^^^^^^^^^^^^^^

Relativizes a target absolute hierarchical URL against a base absolute hierarchical URL with the same scheme and authority, returning a non-empty relative reference accepted by the library. Fails when no such non-empty relative reference can be generated.

| Compilation flags: | static

| Template: | relativize(Base,Target,Relative) | Mode and number of proofs: | relativize(++text,++text,-text) - zero_or_one

---

.. index:: resolve/3 .. _url/1::resolve/3:

resolve/3 ^^^^^^^^^^^^^

Resolves a reference against a base absolute hierarchical URL and returns a normalized absolute URL. The first argument must be an absolute hierarchical URL suitable for use as a base. The second argument may be either a relative reference or an absolute URL; when it is already absolute, the result is that absolute URL normalized and returned unchanged apart from normalization.

| Compilation flags: | static

| Template: | resolve(Base,Reference,Resolved) | Mode and number of proofs: | resolve(++text,++text,-text) - zero_or_one

---

.. index:: normalize/2 .. _url/1::normalize/2:

normalize/2 ^^^^^^^^^^^^^^^

Normalizes a URL or RFC3986 relative reference by standardizing its components. Normalization includes converting the scheme to lowercase when present, normalizing the authority, percent-encoding characters that require escaping, and simplifying path dot segments while preserving absolute and relative reference forms.

| Compilation flags: | static

| Template: | normalize(Reference,NormalizedReference) | Mode and number of proofs: | normalize(++text,-text) - one

---

.. index:: file_path_components/2 .. _url/1::file_path_components/2:

file_path_components/2 ^^^^^^^^^^^^^^^^^^^^^^^^^^

Converts a file-system path into file URL components represented as [authority(Authority), path(Path)]. Windows drive-letter and UNC paths are normalized to RFC3986-compatible file URL components.

| Compilation flags: | static

| Template: | file_path_components(FilePath,Components) | Mode and number of proofs: | file_path_components(++text,-list(compound)) - one

---

Protected predicates

(no local declarations; see entity ancestors if any)

Private predicates

.. index:: downcase_text/2 .. _url/1::downcase_text/2:

downcase_text/2 ^^^^^^^^^^^^^^^^^^^

Converts text to lowercase (ASCII only). Only uppercase letters A-Z are converted to lowercase.

| Compilation flags: | static

| Template: | downcase_text(Text,LowerText) | Mode and number of proofs: | downcase_text(+text,-text) - one

---

Operators

(none)