Architecture

Layers

┌────────────────────────────────────────────┐
│  Swift app (src/)                          │
│  NSWindow, NSMenu, CVDisplayLink           │
│  File I/O, document browser, settings      │
│  NSView with wgpu/Metal layer              │
└────────────────────────────────────────────┘
            │  FFI (viewport/include/acord.h)
            ▼
┌────────────────────────────────────────────┐
│  Rust viewport (viewport/)                 │
│  iced 0.14 + iced_wgpu                     │
│  Editor state, blocks, table widgets       │
│  text_widget (forked text_editor)          │
│  Sidecar archive, crate export             │
└────────────────────────────────────────────┘
            │  acord-core dependency
            ▼
┌────────────────────────────────────────────┐
│  Cordial interpreter (core/)               │
│  Tokenizer, parser, AST, evaluator         │
│  Type system, unit algebra                 │
│  Numerical solver                          │
│  Module system, sidecar persistence        │
└────────────────────────────────────────────┘

Block compositor

Vec<Box<dyn Block>>
Kinds: text, heading, HR, table, computed-table, computed-tree
Iteration over recursion for selection paths
Layered draw order: Below / Content / Above / Top
Source: viewport/src/block.rs, viewport/src/blocks.rs

TextWidget

Forked from iced's text_editor. Per-line fill_paragraph() interleaves anchored child Elements in a sequential stream.

Renderer concretised to iced_wgpu::Renderer
Source: viewport/src/text_widget.rs

Sidecar archive

Base64-encoded ZIP in an HTML comment appended to the .md:

<!-- acord-archive
UEsDBBQAAAAIA…base64…AAAA
-->

Entry	Contents
`config.toml`	Display metadata (col widths, row heights, cell formulas)
`src/<block>.cord`	Per-block TOML front-matter + source

Save: regenerated fresh each write. Load: only config.toml consulted. Source: viewport/src/sidecar.rs.

FFI

C ABI. Header: viewport/include/acord.h (cbindgen-generated).

Function	Purpose
`viewport_create` / `viewport_destroy`	Lifecycle
`viewport_render`	Draw one frame
`viewport_resize`	Reconfigure surface
`viewport_mouse_event` / `viewport_key_event` / `viewport_scroll_event`	Input
`viewport_set_text` / `viewport_get_text`	Document replace / read (handles sidecar)
`viewport_set_lang` / `viewport_set_theme`	Highlighting, theme
`viewport_send_command`	Menu command by integer ID
`viewport_export_crate`	Write standalone Rust crate
`viewport_render_mode`	0=Live, 1=Editor, 2=View
`viewport_free_string`	Free strings returned to Swift

Mouse event sentinel: button == 255 → pointer-move only.

Command IDs

ID	Command
1	ToggleBold
2	ToggleItalic
3	InsertTable
4	SmartEval
5	Evaluate
6	TogglePreview
7	ZoomIn
8	ZoomOut
9	ZoomReset
10	FormatDocument
11	Live mode
12	Editor mode
13	View mode

Cordial interpreter

Hand-rolled tokenizer + recursive-descent parser + tree-walking evaluator.

use spice pre-scanned from source text → tokenizer mode
Implicit multiplication: number adjacent to identifier or ( → Star token insertion
solve! registry parallel to user fns; eval_call checks user fns → solved_fns → builtins
Unit algebra: pure string manipulation
Type system: round-trip coercion

Source: core/src/interp.rs, core/src/eval.rs.