| Title: | Fast 'YAML' 1.2 Parser and Formatter |
| Version: | 0.1.0 |
| Description: | A fast, correct, safe, and ergonomic 'YAML' 1.2 parser and generator written in 'Rust'. Convert between 'YAML' and simple 'R' objects with full support for multi-document streams, tags, anchors, and aliases. Offers opt-in handlers for custom tag behavior and round-trips common 'R' data structures. Implements the 'YAML' 1.2.2 specification from the 'YAML' Language Development Team (2021) https://yaml.org/spec/1.2.2/. Proudly supported by Posit. |
| License: | MIT + file LICENSE |
| URL: | https://posit-dev.github.io/r-yaml12/, https://github.com/posit-dev/r-yaml12 |
| BugReports: | https://github.com/posit-dev/r-yaml12/issues |
| Depends: | R (≥ 4.2) |
| Suggests: | jsonlite, knitr, rmarkdown, testthat (≥ 3.0.0), waldo, withr |
| VignetteBuilder: | knitr |
| Config/Needs/website: | tidyverse/tidytemplate |
| Config/rextendr/version: | 0.4.2.9000 |
| Config/testthat/edition: | 3 |
| Config/testthat/parallel: | false |
| Encoding: | UTF-8 |
| RoxygenNote: | 7.3.3 |
| SystemRequirements: | Cargo (Rust's package manager), rustc >= 1.70.0, xz |
| NeedsCompilation: | yes |
| Packaged: | 2025-12-03 19:56:58 UTC; tomasz |
| Author: | Tomasz Kalinowski [aut, cre],
Posit Software, PBC  [cph,
fnd],
Authors of the dependency Rust crates [cph] (See inst/AUTHORS and
LICENSE.note for vendored Rust dependency authors and licenses.) |
| Maintainer: | Tomasz Kalinowski <tomasz@posit.co> |
| Repository: | CRAN |
| Date/Publication: | 2025-12-11 15:50:02 UTC |
Format or write R objects as YAML 1.2.
Description
format_yaml() returns YAML as a character string. write_yaml() writes a
YAML stream to a file or stdout and always emits document start (---)
markers and a final end (...) marker. Both functions honor a yaml_tag
attribute on values (see examples).
Usage
format_yaml(value, multi = FALSE)
write_yaml(value, path = NULL, multi = FALSE)
Arguments
value |
Any R object composed of lists, atomic vectors, and scalars. |
multi |
When |
path |
Scalar string file path to write YAML to when using |
Value
format_yaml() returns a scalar character string containing YAML.
write_yaml() invisibly returns value.
Examples
cat(format_yaml(list(foo = 1, bar = list(TRUE, NA))))
docs <- list("first", "second")
cat(format_yaml(docs, multi = TRUE))
tagged <- structure("1 + 1", yaml_tag = "!expr")
cat(tagged_yaml <- format_yaml(tagged), "\n")
dput(parse_yaml(tagged_yaml))
write_yaml(list(foo = 1, bar = list(2, "baz")))
write_yaml(list("foo", "bar"), multi = TRUE)
tagged <- structure("1 + 1", yaml_tag = "!expr")
write_yaml(tagged)
Parse YAML 1.2 document(s) into base R structures.
Description
parse_yaml() takes strings of YAML; read_yaml() reads from a file path.
Usage
parse_yaml(text, multi = FALSE, simplify = TRUE, handlers = NULL)
read_yaml(path, multi = FALSE, simplify = TRUE, handlers = NULL)
Arguments
text |
Character vector; elements are concatenated with |
multi |
When |
simplify |
When |
handlers |
Named list of R functions with names corresponding to YAML tags; matching handlers transform tagged values. |
path |
Scalar string path to a YAML file'. |
Details
YAML tags without a corresponding handler are preserved in a yaml_tag attribute.
Mappings with keys that are not all simple scalar strings are returned as a named list with a yaml_keys attribute.
Value
When multi = FALSE, returns a parsed R object for the first document.
When multi = TRUE, returns a list of parsed documents.
Examples
dput(parse_yaml("foo: [1, 2, 3]"))
# homogeneous sequences simplify by default.
# YAML null maps to NA in otherwise homogeneous sequences.
dput(parse_yaml("foo: [1, 2, 3, null]"))
# mixed type sequence never simplify
dput(parse_yaml("[1, true, cat]"))
# use `simplify=FALSE` to always return sequences as lists.
str(parse_yaml("foo: [1, 2, 3, null]", simplify = FALSE))
# Parse multiple documents when requested.
stream <- "
---
first: 1
---
second: 2
"
str(parse_yaml(stream, multi = TRUE))
# Read from a file; keep sequences as lists.
path <- tempfile(fileext = ".yaml")
writeLines("alpha: [true, null]\nbeta: 3.5", path)
str(read_yaml(path, simplify = FALSE))