Package {scholid}

Type: Package
Title: Scholarly and Academic Identifier Utilities
Version: 0.2.0
Language: en-US
Description: Detects, normalizes, classifies, and extracts scholarly identifier strings. Provides lightweight, dependency-free helpers for twenty identifier types, including DOIs, ORCID iDs, ISBNs, ISSNs, arXiv and PubMed identifiers, ROR and ISNI, OpenAlex and ADS bibcodes, RRID, ARK, SWHID, and selected life-science accessions (UniProt, RefSeq, SRA, GEO, BioProject, and genome assemblies). Functions are vectorized, predictable, and suitable as low-level building blocks for other R packages and data workflows. Use 'scholid_types()' for the authoritative type list. For online lookup, conversion, metadata retrieval, and linked identifier discovery, see 'scholidonline'.
License: MIT + file LICENSE
URL: https://thomas-rauter.github.io/scholid/, https://thomas-rauter.github.io/scholidonline/
BugReports: https://github.com/Thomas-Rauter/scholid/issues
Depends: R (≥ 3.5.0)
Suggests: testthat (≥ 3.0.0), knitr (≥ 1.30), rmarkdown
Encoding: UTF-8
RoxygenNote: 7.3.3
Config/testthat/edition: 3
VignetteBuilder: knitr
NeedsCompilation: no
Packaged: 2026-06-04 09:36:59 UTC; thomasrauter
Author: Thomas Rauter ORCID iD [aut, cre, fnd]
Maintainer: Thomas Rauter <rauterthomas0@gmail.com>
Repository: CRAN
Date/Publication: 2026-06-04 16:20:02 UTC

Scholarly and Academic Identifier Utilities

Description

scholid provides lightweight, dependency-free utilities for detecting, normalizing, classifying, and extracting scholarly identifier strings. The package supports twenty identifier types; see scholid_types() for the authoritative list and classification order.

Vignettes

Author(s)

Maintainer: Thomas Rauter rauterthomas0@gmail.com (ORCID) [funder]

See Also

is_scholid(), normalize_scholid(), extract_scholid(), classify_scholid(), detect_scholid_type(), scholid_types()

Classify scholarly identifiers

Description

Performs best-guess classification of scholarly identifier strings. For each element of the input, the function returns the first matching identifier type, or NA_character_ if no supported type matches.

Classification is based on canonical identifier syntax. Types are checked in the order returned by scholid_types() (most specific first); the first match wins. Wrapped forms (e.g., URLs or labels) should be normalized first with normalize_scholid().

Usage

classify_scholid(x)

Arguments

x

A vector of candidate identifier values.

Value

A character vector of the same length as x, giving the detected identifier type for each element, or NA_character_ if no match is found.

See Also

detect_scholid_type(), scholid_types(), scholid_definitions

Examples

classify_scholid(c("10.1000/182", "0000-0002-1825-0097", "not an id"))
classify_scholid(normalize_scholid("https://doi.org/10.1000/182", "doi"))

Detect scholarly identifier types

Description

Performs best-effort detection of scholarly identifier types from possibly wrapped identifier strings (e.g., URLs or labels).

For each element of the input, the function returns the first matching identifier type, or NA_character_ if no supported type matches.

Detection first attempts classification based on canonical identifier syntax (see classify_scholid()). If no match is found, the function attempts per-type normalization (see normalize_scholid()) and returns the first type for which normalization yields a non-missing result. PMID is checked last as a fallback when no more specific type matches.

Use normalize_scholid() to convert detected values to canonical form once the identifier type is known.

Usage

detect_scholid_type(x)

Arguments

x

A vector of candidate identifier values.

Value

A character vector of the same length as x, giving the detected identifier type for each element, or NA_character_ if no match is found.

See Also

classify_scholid(), normalize_scholid(), scholid_types()

Examples

detect_scholid_type(c(
  "https://doi.org/10.1000/182",
  "doi:10.1000/182",
  "https://orcid.org/0000-0002-1825-0097",
  "arXiv:2101.12345v2",
  "PMID: 12345678",
  "PMCID: PMC1234567",
  "not an id"
))

Extract scholarly identifiers from text

Description

Extract identifiers of a single supported type from free text.

The result is a list with one element per input element. Each element is a character vector of matches (possibly length 0). NA inputs yield an empty character vector.

Matches are returned as extracted identifier tokens from the text. Surrounding prose punctuation or markup fragments may be removed where necessary to isolate the identifier. Use normalize_scholid() to convert identifiers to canonical form.

Usage

extract_scholid(text, type)

Arguments

text

A character vector of text.

type

A single string giving the identifier type. See scholid_types() for supported values.

Value

A list of character vectors of extracted identifiers.

Examples

extract_scholid("See https://doi.org/10.1000/182.", "doi")
extract_scholid("ORCID 0000-0002-1825-0097", "orcid")

Test scholarly identifier validity

Description

Vectorized predicate that tests whether values are valid scholarly identifiers of a given supported type.

For identifier types with checksum algorithms (e.g., ORCID, ROR, ISNI, ISBN, ISSN), checksum correctness is verified. The same checksum rules apply to normalize_scholid().

The main difference from normalization is input form: is_scholid() expects values in canonical (or near-canonical) form. Wrapped values such as URLs or prefixed labels should be normalized first with normalize_scholid().

Inputs that are NA yield NA. Non-matching values return FALSE.

Usage

is_scholid(x, type)

Arguments

x

A vector of values to test.

type

A single string giving the identifier type. See scholid_types() for supported values.

Value

A logical vector of the same length as x, indicating whether each element is a valid identifier of the specified type.

See Also

normalize_scholid(), scholid_types()

Examples

is_scholid("10.1000/182", "doi")
is_scholid("0000-0002-1825-0097", "orcid")

Normalize scholarly identifiers

Description

Vectorized normalizer that converts supported scholarly identifier values to a canonical form (e.g., removing URL prefixes, labels, or separators).

Normalization requires that inputs match the expected identifier structure. For identifier types with checksum algorithms (ORCID, ROR, ISNI, ISBN, ISSN), normalization also requires checksum-valid values. Inputs that do not meet these requirements yield NA_character_.

Normalized outputs are canonical, type-specific representations of valid identifiers.

Use is_scholid() to test whether already-canonical values are valid identifiers of a given type. Both functions apply checksum verification where applicable; normalization additionally accepts wrapped input forms and returns canonical strings.

Usage

normalize_scholid(x, type)

Arguments

x

A vector of values to normalize.

type

A single string giving the identifier type. See scholid_types() for supported values.

Value

A character vector with the same length as x. Invalid, checksum- failing, or structurally non-matching inputs yield NA_character_.

See Also

is_scholid(), scholid_types()

Examples

normalize_scholid("https://doi.org/10.1000/182", "doi")
normalize_scholid("https://orcid.org/0000-0002-1825-0097", "orcid")

Supported scholid identifier types

Description

Returns the set of identifier types supported by the scholid package in classification priority order (most specific first). The package currently supports twenty types (from DOI and ORCID through life-science and archive identifiers). For per-type formats, validation rules, and classification precedence, see the How Scholarly Identifiers Are Defined vignette (vignette("scholid_definitions", package = "scholid")).

Usage

scholid_types()

Value

A character vector of supported identifier type strings.

Examples

scholid_types()
"orcid" %in% scholid_types()