Module engine 

Spreadsheet engine API.

This module provides the core computation engine for the spreadsheet:

• Cell, CellType, Grid - Data structures for cell storage
• CellRef - Cell reference parsing (A1 notation ↔ row/col indices)
• detect_cycle - Circular dependency detection
• extract_dependencies - Parse formula dependencies
• preprocess_script - Transform formulas for Rhai evaluation
• create_engine - Create a Rhai engine with built-in functions
• format_dynamic - Format values for display

Structs

AST

Compiled AST (abstract syntax tree) of a Rhai script.

Cell

A cell in the spreadsheet grid.

CellRef

A reference to a cell by row and column indices (0-indexed).

Dynamic

Dynamic type containing any value.

Enums

CellType

The type of content stored in a cell.

ShiftOperation

Operation for shifting cell references in formulas.

Functions

create_engine

Create a Rhai engine with built-ins registered.

create_engine_with_functions

Create a Rhai engine with built-ins registered. Optionally compiles custom functions from the provided script. Returns the engine, compiled AST (if any), and any error message.

create_engine_with_functions_and_spill

Create a Rhai engine with built-ins, custom functions, and shared maps. Returns the engine, compiled AST (if any), and any error message.

create_engine_with_spill

Create a Rhai engine with built-ins registered and shared maps.

detect_cycle

Detect circular dependencies starting from a cell. Returns Some(cycle_path) if a cycle is found, None otherwise.

eval_with_functions

Evaluate a formula, optionally with custom functions AST.

extract_dependencies

Extract all cell references from a script as dependencies.

format_dynamic

Format a Dynamic value for display.

format_number

Format a number for display.

parse_range

Parse a cell range like “A1:B5” and return (start_row, start_col, end_row, end_col).

preprocess_script

Replace cell references like “A1” with Rhai function calls like “cell(0, 0)”. Typed refs like “@A1” become “value(0, 0)” (returns Dynamic). Also transforms range functions like SUM(A1:B5, …) into sum_range(0, 0, 4, 1, …).

preprocess_script_with_context

Preprocess script with optional current cell context for ROW()/COL(). When context is provided, ROW() and COL() are replaced with 1-based row/col values.

shift_formula_references

Shift cell references in a formula when rows/cols are inserted/deleted. Returns the updated formula string.

Type Aliases

ComputedMap

Thread-safe storage for computed formula cell values. Maps cell positions to their evaluated Dynamic values. This allows cell references to use pre-computed values instead of re-evaluating.

Grid

Thread-safe sparse grid storage.

SpillMap

Thread-safe storage for spill cell values. Maps cell positions to their computed Dynamic values.