Crate fml_syntax 

Lossless syntax tree, error-tolerant parser and formatter for the FHIR Mapping Language.

let parse = fml_syntax::parse(r#"
uses "http://hl7.org/fhir/StructureDefinition/Patient" as source
uses "http://hl7.org/fhir/StructureDefinition/Patient" as target

group Copy(source src : Patient, target tgt : Patient) {
  src.name -> tgt.name;
}
"#);
assert!(parse.diagnostics().is_empty());

let file = parse.tree();
let group = file.groups().next().unwrap();
assert_eq!(group.name().as_deref(), Some("Copy"));

The tree keeps every byte of the input, comments and whitespace included, so parse(text).syntax().to_string() == text for any input.

Re-exports

pub use ast::AstNode;

Modules

ast

Typed views over the syntax tree.

Structs

Diagnostic

A problem found in the source, located by byte range.

FormatOptions

LineCol

A position in the source: zero-based line, and zero-based column counted both in UTF-8 bytes and in UTF-16 code units (the unit LSP and the Mapping Language debug trace use).

LineIndex

Converts byte offsets to line and column.

Parse

The result of parsing: a syntax tree that covers the whole input, plus the problems found.

TextRange

A range in text, represented as a pair of TextSize.

TextSize

A measure of text length. Also, equivalently, an index into text.

Token

A token: its kind and where it is in the source.

Enums

Direction

FmlLanguage

The rowan language tag for FML trees.

FormatError

NodeOrToken

Severity

SyntaxKind

Every token and node kind in an FML syntax tree.

Functions

expression_text

Renders a FHIRPath expression in canonical form: one space around binary operators, none inside paths and calls, comments dropped, strings single-quoted. This is the form StructureMap stores expressions in, and the one the HL7 reference compiler produces.

format

Formats FML source text.

format_tree

Formats a parsed tree without checking it first. Prefer [format], which refuses trees with syntax errors and verifies the result.

parse

Parses FML source text. Never fails; see Parse::diagnostics.

quote_fhirpath_string

Writes value as a single-quoted FHIRPath string literal.

tokenize

Splits source into tokens. Every byte of the source belongs to exactly one token, so the concatenated token texts always equal the source. Malformed input produces SyntaxKind::Unknown tokens and a diagnostic for each.

Type Aliases

SyntaxElement

SyntaxNode

SyntaxToken