Struct SourcePosition 

pub struct SourcePosition { /* private fields */ }

Source position information for parsing, with dual column tracking.

This is a pure data struct with no mutation methods. Lexers are responsible for computing position values as they scan input.

This is standalone with no dependency on libgraphql-core. All fields are private with accessor methods.

Indexing Convention

All position values are 0-based:

• line: 0 = first line of the document (0-based)
• col_utf8: UTF-8 character count within the current line (0-based)
• col_utf16: Optional UTF-16 code unit offset within the current line (0-based)
• byte_offset: byte offset within the whole document (0-based)

Dual Column Tracking

Two column representations are supported:

• col_utf8 (always available): Number of UTF-8 characters from the start of the current line. Increments by 1 for each character regardless of its byte representation. This is intuitive for users and matches what most text editors display as “column”.
• col_utf16 (optional): UTF-16 code unit offset within the line. This aligns with LSP (Language Server Protocol) and many editors. It is Some when the token source can provide it (e.g. StrToGraphQLTokenSource), and None when it cannot (e.g. RustMacroGraphQLTokenSource in libgraphql-macros which uses proc_macro2::Span that only provides UTF-8 char-based positions).

For ASCII text, both columns are equal. For text containing characters outside the Basic Multilingual Plane (e.g., emoji), they differ:

• col_utf8 advances by 1 for each UTF-8 character
• col_utf16 advances by the character’s UTF-16 length (1 or 2 code units)

Size

This struct is 20 bytes (4 × u32 + Option<u32>) and derives Copy for cheap value semantics. The u32 fields support files up to 4 GB and lines/columns up to ~4 billion — more than sufficient for any realistic GraphQL document. Accessors return usize for ergonomic interop with Rust’s standard indexing types.

Implementations

impl SourcePosition

pub fn new( line: usize, col_utf8: usize, col_utf16: Option<usize>, byte_offset: usize, ) -> Self

Create a new SourcePosition.

Arguments

• line: 0-based line number (0 = first line)
• col_utf8: 0-based UTF-8 character count within current line
• col_utf16: 0-based UTF-16 code unit offset within current line, or None if not available (e.g., from proc_macro2::Span)
• byte_offset: 0-based byte offset from document start

pub fn line(&self) -> usize

Returns the 0-based line number.

pub fn line_col(&self) -> (u32, u32)

Returns the 0-based (line, col_utf8) tuple as u32 values.

This is a low-level accessor that returns the raw stored u32 fields without converting to usize. Useful for compact representations (e.g. serialization, span maps).

pub fn col_utf8(&self) -> usize

Returns the 0-based (UTF-8) character count within the current line.

This increments by 1 for each character regardless of byte representation. For example, both ‘a’ (1 byte) and ‘🎉’ (4 bytes) each add 1 to this count.

pub fn col_utf16(&self) -> Option<usize>

Returns the 0-based UTF-16 code unit offset within the current line, if available.

This is Some when the token source can provide UTF-16 column information (e.g., StrToGraphQLTokenSource), and None when it cannot (e.g., RustMacroGraphQLTokenSource in libgraphql-macros).

For example, ‘a’ (1 UTF-16 code unit) adds 1 to this count, while ‘🎉’ (a surrogate pair requiring 2 UTF-16 code units) adds 2 to this count.

For LSP compatibility, prefer this method when available.

pub fn byte_offset(&self) -> usize

Returns the 0-based byte offset from document start.

Trait Implementations

impl Clone for SourcePosition

fn clone(&self) -> SourcePosition

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SourcePosition

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for SourcePosition

fn eq(&self, other: &SourcePosition) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for SourcePosition

impl Eq for SourcePosition

impl StructuralPartialEq for SourcePosition