Crate libyml 

👎Deprecated since 0.0.6:

libyml is unmaintained. Migrate to a maintained alternative (unsafe-libyaml, yaml-rust2, or noyalib). See MIGRATION.md.

⚠️ libyml is deprecated — migrate to a maintained alternative

This crate is unmaintained. The 0.0.6 release is a thin compatibility shim so existing call sites keep working while you plan a migration. See MIGRATION.md for the full guide.

Maintained alternatives

• unsafe-libyaml — the upstream Rust translation of C libyaml that libyml was originally forked from. Same yaml_* function surface, actively maintained. Drop-in replacement for users on the raw FFI-shaped API.
• yaml-rust2 — pure-Rust low-level parser, no FFI. Returns a Yaml enum AST instead of the event-stream model. Fits users who want to move off the C-libyaml shape entirely while keeping a low-level parser primitive.
• noyalib — modern, pure-Rust, #![forbid(unsafe_code)] YAML library with a high-level typed API (from_str::<T> / Value). Fits users who can move from event-stream parsing to typed deserialisation.

MIGRATION.md carries the per-crate mapping tables.

Why the shim is backed by unsafe-libyaml

libyml was originally a fork of unsafe-libyaml with cosmetic renames (snake_case → PascalCase for type names). The 0.0.6 shim reverts those renames internally and re-exports the upstream’s functions and types, restoring the historical PascalCase aliases so existing call sites compile unchanged.

This is an implementation detail, not a recommendation that you must use unsafe-libyaml. Two things follow:

• No duplicated unsafe translation in the dependency graph. Downstream users link the upstream’s audited copy of the C-libyaml translation rather than this fork’s stale copy.
• Bug fixes flow through. Anything fixed in unsafe-libyaml lands in users of this shim on a plain cargo update, without a new libyml release.

If you want to evaluate yaml-rust2 or noyalib directly, MIGRATION.md covers both.

Stop-gap: keep using libyml = "0.0.6"

Existing call sites compile unchanged against this shim. Every item below is marked #[deprecated], so the compiler will point at the spots that need updating during your migration.

What still resolves under libyml::* (0.0.6)

Most of the previous public surface is retained via thin re-export modules pointing at unsafe-libyaml:

• libyml::api — parser/emitter init + event initialisers.
• libyml::decode — yaml_parser_initialize / _delete.
• libyml::document — yaml_document_* helpers.
• libyml::dumper — yaml_emitter_open / _close / _dump.
• libyml::loader — yaml_parser_load.
• libyml::yaml — every PascalCase type alias and PascalCase enum-variant constant.
• libyml::success — is_success(bool) / is_failure(bool) helpers (the Success struct itself is no longer nameable — read .ok instead).

The historical libyml::memory and libyml::string paths still resolve, but as empty stub modules — every former item under them is gone because they belonged to the hand-translated C copy this shim deletes (libyml::string::yaml_string_extend is the unsound helper RUSTSEC-2025-0067 flags).

Removed in 0.0.6 (vs. 0.0.5)

The implementation-detail modules — libyml::internal, libyml::macros, libyml::externs, libyml::utils, libyml::libc, the contents of libyml::memory and libyml::string, and the yaml-test-suite runner binaries under src/bin/ — are gone in this release. See MIGRATION.md for the equivalence table per alternative.

Modules

apiDeprecated

API-surface helpers. Re-exported from the crate root for source compatibility with libyml ≤ 0.0.5’s libyml::api module.

decodeDeprecated

Parser-decode helpers. Re-exported from the crate root for source compatibility with libyml ≤ 0.0.5’s libyml::decode module.

documentDeprecated

Document-tree helpers. Re-exported from the crate root for source compatibility with libyml ≤ 0.0.5’s libyml::document module.

dumperDeprecated

Emitter dumper helpers. Re-exported from the crate root for source compatibility with libyml ≤ 0.0.5’s libyml::dumper module. Note: the previous releases also exposed yaml_emitter_dump_node / _scalar / _sequence / _mapping as pub items; the upstream keeps those private. Callers should drive emission through the public yaml_emitter_dump entry point.

loaderDeprecated

Event-loader helpers. Re-exported from the crate root for source compatibility with libyml ≤ 0.0.5’s libyml::loader module. Note: the previous releases also exposed yaml_parser_set_composer_error as a pub item; the upstream surfaces composer errors through yaml_parser_parse / yaml_parser_load directly, so callers that constructed composer errors manually need to switch to inspecting parser.problem after the regular parse APIs return failure.

memoryDeprecated

Removed in 0.0.6. Previous releases exposed a hand-translated C-libyaml allocator surface (yaml_malloc / yaml_free / yaml_realloc / yaml_strdup). Those helpers were implementation details of the hand-translated parser, which the 0.0.6 shim deletes; the upstream unsafe-libyaml uses Rust’s alloc directly. Allocate with Rust’s standard primitives instead. This empty module is retained so that use libyml::memory; keeps resolving — every former item under it is gone.

stringDeprecated

Removed in 0.0.6 — see RUSTSEC-2025-0067. Previous releases exposed yaml_string_extend / yaml_string_join helpers under this path. The 0.0.6 shim deletes the entire hand-translated C copy that those helpers belonged to. Build strings with Rust’s Vec / String instead. This empty module is retained so use libyml::string; keeps resolving — every former item under it is gone.

successDeprecated

Success/failure helpers retained for source compatibility with libyml ≤ 0.0.5.

yamlDeprecated

Type aliases. Re-exported from the crate root for source compatibility with libyml ≤ 0.0.5’s libyml::yaml module — all Yaml*T PascalCase types and Yaml* PascalCase enum variants land at this path too.

Constants

YamlAliasEventDeprecated

Alias for unsafe_libyaml::YAML_ALIAS_EVENT.

YamlAnyEncodingDeprecated

Alias for unsafe_libyaml::YAML_ANY_ENCODING.

YamlAnyMappingStyleDeprecated

Alias for unsafe_libyaml::YAML_ANY_MAPPING_STYLE.

YamlAnyScalarStyleDeprecated

Alias for unsafe_libyaml::YAML_ANY_SCALAR_STYLE.

YamlAnySequenceStyleDeprecated

Alias for unsafe_libyaml::YAML_ANY_SEQUENCE_STYLE.

YamlBlockMappingStyleDeprecated

Alias for unsafe_libyaml::YAML_BLOCK_MAPPING_STYLE.

YamlBlockSequenceStyleDeprecated

Alias for unsafe_libyaml::YAML_BLOCK_SEQUENCE_STYLE.

YamlComposerErrorDeprecated

Alias for unsafe_libyaml::YAML_COMPOSER_ERROR.

YamlDocumentEndEventDeprecated

Alias for unsafe_libyaml::YAML_DOCUMENT_END_EVENT.

YamlDocumentStartEventDeprecated

Alias for unsafe_libyaml::YAML_DOCUMENT_START_EVENT.

YamlDoubleQuotedScalarStyleDeprecated

Alias for unsafe_libyaml::YAML_DOUBLE_QUOTED_SCALAR_STYLE.

YamlEmitterErrorDeprecated

Alias for unsafe_libyaml::YAML_EMITTER_ERROR.

YamlFlowMappingStyleDeprecated

Alias for unsafe_libyaml::YAML_FLOW_MAPPING_STYLE.

YamlFlowSequenceStyleDeprecated

Alias for unsafe_libyaml::YAML_FLOW_SEQUENCE_STYLE.

YamlFoldedScalarStyleDeprecated

Alias for unsafe_libyaml::YAML_FOLDED_SCALAR_STYLE.

YamlLiteralScalarStyleDeprecated

Alias for unsafe_libyaml::YAML_LITERAL_SCALAR_STYLE.

YamlMappingEndEventDeprecated

Alias for unsafe_libyaml::YAML_MAPPING_END_EVENT.

YamlMappingNodeDeprecated

Alias for unsafe_libyaml::YAML_MAPPING_NODE.

YamlMappingStartEventDeprecated

Alias for unsafe_libyaml::YAML_MAPPING_START_EVENT.

YamlMemoryErrorDeprecated

Alias for unsafe_libyaml::YAML_MEMORY_ERROR.

YamlNoErrorDeprecated

Alias for unsafe_libyaml::YAML_NO_ERROR.

YamlNoEventDeprecated

Alias for unsafe_libyaml::YAML_NO_EVENT.

YamlNoNodeDeprecated

Alias for unsafe_libyaml::YAML_NO_NODE.

YamlParserErrorDeprecated

Alias for unsafe_libyaml::YAML_PARSER_ERROR.

YamlPlainScalarStyleDeprecated

Alias for unsafe_libyaml::YAML_PLAIN_SCALAR_STYLE.

YamlReaderErrorDeprecated

Alias for unsafe_libyaml::YAML_READER_ERROR.

YamlScalarEventDeprecated

Alias for unsafe_libyaml::YAML_SCALAR_EVENT.

YamlScalarNodeDeprecated

Alias for unsafe_libyaml::YAML_SCALAR_NODE.

YamlScannerErrorDeprecated

Alias for unsafe_libyaml::YAML_SCANNER_ERROR.

YamlSequenceEndEventDeprecated

Alias for unsafe_libyaml::YAML_SEQUENCE_END_EVENT.

YamlSequenceNodeDeprecated

Alias for unsafe_libyaml::YAML_SEQUENCE_NODE.

YamlSequenceStartEventDeprecated

Alias for unsafe_libyaml::YAML_SEQUENCE_START_EVENT.

YamlSingleQuotedScalarStyleDeprecated

Alias for unsafe_libyaml::YAML_SINGLE_QUOTED_SCALAR_STYLE.

YamlStreamEndEventDeprecated

Alias for unsafe_libyaml::YAML_STREAM_END_EVENT.

YamlStreamStartEventDeprecated

Alias for unsafe_libyaml::YAML_STREAM_START_EVENT.

YamlUtf8EncodingDeprecated

Alias for unsafe_libyaml::YAML_UTF8_ENCODING.

YamlUtf16beEncodingDeprecated

Alias for unsafe_libyaml::YAML_UTF16BE_ENCODING.

YamlUtf16leEncodingDeprecated

Alias for unsafe_libyaml::YAML_UTF16LE_ENCODING.

YamlWriterErrorDeprecated

Alias for unsafe_libyaml::YAML_WRITER_ERROR.

Functions

yaml_alias_event_initialize^⚠

Create an ALIAS event.

yaml_document_delete^⚠

Delete a YAML document and all its nodes.

yaml_document_end_event_initialize^⚠

Create the DOCUMENT-END event.

yaml_document_get_node^⚠

Get a node of a YAML document.

yaml_document_get_root_node^⚠

Get the root of a YAML document node.

yaml_document_initialize^⚠

Create a YAML document.

yaml_document_start_event_initialize^⚠

Create the DOCUMENT-START event.

yaml_emitter_close^⚠

Finish a YAML stream.

yaml_emitter_delete^⚠

Destroy an emitter.

yaml_emitter_dump^⚠

Emit a YAML document.

yaml_emitter_emit^⚠

Emit an event.

yaml_emitter_flush^⚠

Flush the accumulated characters to the output.

yaml_emitter_initialize^⚠

Initialize an emitter.

yaml_emitter_open^⚠

Start a YAML stream.

yaml_emitter_set_break^⚠

Set the preferred line break.

yaml_emitter_set_canonical^⚠

Set if the output should be in the “canonical” format as in the YAML specification.

yaml_emitter_set_encoding^⚠

Set the output encoding.

yaml_emitter_set_indent^⚠

Set the indentation increment.

yaml_emitter_set_output^⚠

Set a generic output handler.

yaml_emitter_set_output_string^⚠

Set a string output.

yaml_emitter_set_unicode^⚠

Set if unescaped non-ASCII characters are allowed.

yaml_emitter_set_width^⚠

Set the preferred line width. -1 means unlimited.

yaml_event_delete^⚠

Free any memory allocated for an event object.

yaml_mapping_end_event_initialize^⚠

Create a MAPPING-END event.

yaml_mapping_start_event_initialize^⚠

Create a MAPPING-START event.

yaml_parser_delete^⚠

Destroy a parser.

yaml_parser_initialize^⚠

Initialize a parser.

yaml_parser_load^⚠

Parse the input stream and produce the next YAML document.

yaml_parser_parse^⚠

Parse the input stream and produce the next parsing event.

yaml_parser_scan^⚠

Scan the input stream and produce the next token.

yaml_parser_set_encoding^⚠

Set the source encoding.

yaml_parser_set_input^⚠

Set a generic input handler.

yaml_parser_set_input_string^⚠

Set a string input.

yaml_scalar_event_initialize^⚠

Create a SCALAR event.

yaml_sequence_end_event_initialize^⚠

Create a SEQUENCE-END event.

yaml_sequence_start_event_initialize^⚠

Create a SEQUENCE-START event.

yaml_stream_end_event_initialize^⚠

Create the STREAM-END event.

yaml_stream_start_event_initialize^⚠

Create the STREAM-START event.

yaml_token_delete^⚠

Free any memory allocated for a token object.

Type Aliases

YamlAliasDataTDeprecated

Alias for unsafe_libyaml::yaml_alias_data_t.

YamlBreakTDeprecated

Alias for unsafe_libyaml::yaml_break_t.

YamlDocumentTDeprecated

Alias for unsafe_libyaml::yaml_document_t.

YamlEmitterStateTDeprecated

Alias for unsafe_libyaml::yaml_emitter_state_t.

YamlEmitterTDeprecated

Alias for unsafe_libyaml::yaml_emitter_t.

YamlEncodingTDeprecated

Alias for unsafe_libyaml::yaml_encoding_t.

YamlErrorTypeTDeprecated

Alias for unsafe_libyaml::yaml_error_type_t.

YamlEventTDeprecated

Alias for unsafe_libyaml::yaml_event_t.

YamlEventTypeTDeprecated

Alias for unsafe_libyaml::yaml_event_type_t.

YamlMappingStyleTDeprecated

Alias for unsafe_libyaml::yaml_mapping_style_t.

YamlMarkTDeprecated

Alias for unsafe_libyaml::yaml_mark_t.

YamlNodeItemTDeprecated

Alias for unsafe_libyaml::yaml_node_item_t.

YamlNodePairTDeprecated

Alias for unsafe_libyaml::yaml_node_pair_t.

YamlNodeTDeprecated

Alias for unsafe_libyaml::yaml_node_t.

YamlNodeTypeTDeprecated

Alias for unsafe_libyaml::yaml_node_type_t.

YamlParserStateTDeprecated

Alias for unsafe_libyaml::yaml_parser_state_t.

YamlParserTDeprecated

Alias for unsafe_libyaml::yaml_parser_t.

YamlReadHandlerTDeprecated

Alias for unsafe_libyaml::yaml_read_handler_t.

YamlScalarStyleTDeprecated

Alias for unsafe_libyaml::yaml_scalar_style_t.

YamlSequenceStyleTDeprecated

Alias for unsafe_libyaml::yaml_sequence_style_t.

YamlSimpleKeyTDeprecated

Alias for unsafe_libyaml::yaml_simple_key_t.

YamlStackTDeprecated

Alias for unsafe_libyaml::yaml_stack_t.

YamlTagDirectiveTDeprecated

Alias for unsafe_libyaml::yaml_tag_directive_t.

YamlTokenTDeprecated

Alias for unsafe_libyaml::yaml_token_t.

YamlTokenTypeTDeprecated

Alias for unsafe_libyaml::yaml_token_type_t.

YamlVersionDirectiveTDeprecated

Alias for unsafe_libyaml::yaml_version_directive_t.

YamlWriteHandlerTDeprecated

Alias for unsafe_libyaml::yaml_write_handler_t.