About¶

1. About lext¶

lex is a plain text document format for structured documents. It combines the immediacy of plain text with the rigor of hierarchical, machine-readable markup so you can stay in the flow from first note to published artifact.

2. The Format¶

lex documents rely on indentation and a small set of markers to reveal structure. The syntax stays invisible so authors focus on ideas, not delimiters.

2.1. Core Elements¶

Session

``` lex :: Hierarchical sections with numbered titles.

**Example**

``` lex ::
1. Introduction

    Content indented under the title belongs to this section.

    1.1. Subsection

        Nested content at deeper levels.

Definition

``` lex :: Term: The definition follows immediately after the colon, indented one level.

**Lists**

``` lex ::
- Unordered item
- Another item

1. Ordered item
2. Another ordered item
    a. Nested alphabetical
    b. Another nested

Verbatim Blocks

``` lex :: Example Code: function hello() { return "world"; } :: javascript ::

**Tables**

``` lex ::
Comparison:
    | Format   | Tables | Spanning |
    | lex      | Native | Yes      |
    | Markdown | Basic  | No       |

    :: table align=lcc ::

Annotation

``` lex :: :: note :: This is a single-line annotation.

:: todo status=open :: This is a block annotation with multiple lines. :: ```

2.2. Inline Formatting¶

*bold* for strong emphasis
_italic_ for emphasis
`` code `` for inline code
#math# for mathematical notation
[reference] for links, citations, footnotes

2.3. Reference Types¶

[https://example.com] - URLs
[@author2024] - Citations
[42] - Footnotes
[::label] - Annotation references
[#2.1] - Session references
[./file.txt] - File references
[TK-placeholder] - Placeholders

3. Implementation¶

The reference implementation lives in Rust crates under the lex-fmt organization. Each crate focuses on a specific role in the toolchain:

Definition: lex-core; Parser with a five-phase pipeline.
Definition: lex-babel; Format conversion for Markdown, HTML, PDF, and more.
Definition: lex-analysis; Document analysis powering editor features.
Definition: lex-lsp; Language Server Protocol implementation.
Definition: lex-cli; Command-line interface.
Definition: lex-config; Configuration loader shared by the CLI and tools.

All crates are published to.

4. Design Principles¶

Invisible syntax: Structure emerges from indentation and textual conventions.
Graceful degradation: Unmatched constructs become paragraphs instead of errors.
Complete lifecycle: Scales from quick notes to finished documents.
Tool-friendly: Deterministic grammar for reliable parsing.
Future-proof: Plain Unicode text, no proprietary containers.

5. License¶

lex is open source. See each repository for license details.