Crate xl3_core 

xl3-core — pure-Rust XLSX template rendering engine.

Reads an Excel template plus a data workbook, evaluates the XTL expressions inside template cells, and emits a rendered XLSX buffer. This is the same engine that powers the xl3-wasm npm package; it can also be embedded directly in Rust CLIs, Tauri desktop apps, or server-side batch jobs.

Quick start

use xl3_core::render_from_bytes_to_files;

let template = std::fs::read("template.xlsx").unwrap();
let data = std::fs::read("data.xlsx").unwrap();
let files = render_from_bytes_to_files(&template, &data).unwrap();
std::fs::write(&files[0].filename, &files[0].data).unwrap();

Pipeline

1. plan — parse the template workbook + __config__ sheet into a WorkbookPlan of static and expansion rows.
2. source — read the data workbook into row records.
3. [render] — walk the plan, evaluating each cell through eval, and emit cells through output.

See the parent repository’s PLAN.md for the broader roadmap.

Re-exports

pub use errors::is_xtl_error;

pub use errors::XtlError;

pub use introspect::preview;

pub use introspect::preview_bytes;

pub use introspect::read_template_inputs;

pub use introspect::read_template_inputs_bytes;

pub use introspect::InputKind;

pub use introspect::InputSpec;

pub use introspect::PreviewFile;

pub use introspect::PreviewResult;

pub use introspect::PreviewSheet;

pub use introspect::PreviewSource;

pub use manifest::AlignmentSpec;

pub use manifest::ColumnWidth;

pub use manifest::FillPattern;

pub use manifest::FillSpec;

pub use manifest::FontSpec;

pub use manifest::HorizontalAlign;

pub use manifest::StyleManifest;

pub use manifest::StyleSpec;

pub use manifest::VerticalAlign;

pub use output_model::OutputFile;

pub use output_model::XtlWarning;

pub use plan::parse_template;

pub use plan::parse_template_bytes;

pub use plan::CellSource;

pub use plan::RowPlan;

pub use plan::SheetPlan;

pub use plan::WorkbookPlan;

pub use render::render;

pub use render::render_from_bytes_to_files;

pub use render::render_from_bytes_to_files_full;

pub use render::render_from_bytes_to_files_with_inputs;

pub use render::render_to_files;

pub use source::CalamineSourceReader;

pub use source::SourceData;

pub use source::SourceReader;

pub use value::Value;

pub use calamine;

pub use rust_xlsxwriter;

Modules

directives

Directive parsing.

errors

Stable error-code surface, mirroring xl3 (TS)’s XtlError / xtlError / isXtlError (ADR-0015) and xl3-py’s XtlError.

eval

Expression parser + evaluator for XTL templates.

functions

Context-free scalar function implementations.

introspect

Surface-area parity with xl3 (TS) / xl3-py introspection APIs.

manifest

Style manifest model exchanged with the JS shell.

output

Output buffer assembly.

output_model

Public output types — mirror the TS / Python sibling APIs so that xl3-wasm and any other host can return the same OutputFile[] shape that convert() produces in xl3 (TS) and xl3-py.

plan

Template plan: the parsed, evaluation-ready representation of a template workbook.

render

Top-level renderer. Glues plan + source + eval + output.

source

Source data reader. Reads the data workbook (data.xlsx) into row records keyed by the header row.

styles

Parse the bits of a template workbook that calamine doesn’t expose: the xl/styles.xml numFmt / cellXfs tables, and each worksheet’s cell-level s="<xf>" attribute. We need this for ADR-0003 numFmt cell coercion ({{ [Amount] }} in a numeric-format cell yields a Number, not the source string).

value

Cell value representation used by the planner, source reader, and evaluator. Deliberately simple — strings, numbers, booleans, plus an explicit Empty so we can distinguish “blank cell” from “empty string”.