A Rust port of calc (Landon Curt Noll's arbitrary-precision calc…

What is toRustCalcMCP?

A Rust port of Landon Curt Noll’s arbitrary‑precision calculator (calc) that provides three interfaces: a command‑line calculator (rcalc), a web REPL, and an MCP server for LLM/agent integration. It uses exact rational arithmetic (num‑rational over num‑bigint) so computations like 1/3 * 3 yield exactly 1.

How to use toRustCalcMCP?

Build with cargo build --release. Use the CLI via rcalc 'expression', the web REPL with rcalc-web (served on localhost:8888), or the MCP server with toRustCalcMCP --mcp. For MCP, perform the initialize handshake then call tools like calc_eval, calc_config, or calc_functions. A detailed MCP tool schema is provided in the repository.

Key features of toRustCalcMCP

• 351 builtins (100%+ coverage of calc’s ~350 functions)
• Exact rational arithmetic – no floating‑point approximations
• Three interfaces: CLI, web REPL, and MCP server
• Arbitrary‑precision transcendentals via Taylor series and Newton’s method
• User‑defined functions, control flow (if/else, while, for), and lists
• Session‑configurable precision and display mode

Use cases of toRustCalcMCP

• Perform arbitrary‑precision arithmetic from the command line
• Explore and test calc functions interactively in a browser
• Integrate exact‑rational computation into LLM agents via MCP tools
• Replace the original C calc with a portable Rust‑based version

FAQ from toRustCalcMCP

What precision does toRustCalcMCP use?

Numbers are exact rationals. Irrational results are approximated to within a session epsilon (default 1e-20). Transcendentals like sin, cos, and exp are computed via Taylor series until the term is smaller than epsilon.

How many builtin functions are implemented?

351 builtins are implemented, covering 100% of calc’s ~350 functions. Core categories (arithmetic, number theory, trigonometry, transcendental, bitwise, lists, strings, etc.) are fully or partially implemented; about 100 exotic/specialized functions (e.g., rare trig variants, file I/O, cryptography) are not yet added.

What transport does the MCP server use?

The MCP server uses JSON‑RPC 2.0 over stdio. Clients must perform initialize, then tools/list, and then tools/call with the appropriate arguments.

Is toRustCalcMCP compatible with the original calc language?

Yes. It supports the same expression syntax, operators, variables, user‑