arcesino / mncalc

Command line mixed numbers calculator

mncalc

Command line mixed numbers calculator written in Rust

How to build

You need to have Rust installed in order to build the utility. Instalation instructions are available at: https://www.rust-lang.org/learn/get-started Once installed, you only need to navigate to the root of the repo and run the following command:

$ cargo run --release

The command above will build the project with release optimizations & run the utility in REPL mode. Cargo also generates the program executable under target/release/mncalc.

Run modes

This utility can work in 2 different modes:

REPL mode

This is the default mode and makes the utility run in an interactive mode and allows the user to enter several expressions to be evaluated. The program will keep running until the user enters 'q'. To run the utility in REPL mode you just need to execute the program without specifying any options:

$ cargo run --release

or

# from the repo root
$ ./target/release/mncalc

Find below an example of the utility running in REPL mode:

$ target/release/mncalc
Starting repl mode. Type 'q' to quit

? 1/2 * 3_3/4
= 1_7/8
? 1/2
Error: Unparseable operation!
? 2_3/8 + 9/8
= 3_1/2
? 1_3/7 - 5_2/4
= -4_1/14
? 3/0 + 2_2/5
Error: Fraction with zero denominator!
? 7 / 3_1/4
= 2_2/13
? 25/13 / 0/11
Error: Division by zero!
? q

Single evaluation mode

In this mode, the utility will evaluate an expression passed as a command line option. The program will terminate right after the given expression gets evaluated. To run the utility in single evaluation mode you just need to execute the program specifying the expression to evaluate:

$ cargo run --release -- -e "1/2 * 3_3/4"

or

# from the repo root
$ ./target/release/mncalc --eval "1/2 * 3_3/4"

As you may've noticed, you can specify the expression to evaluate using short option (-e) or long option (--eval). For more details, you can ask the utility for help:

$ target/release/mncalc -h
mncalc 0.1.0
Ignacio Arces <[e-mail]>
Simple Mixed Numbers Calculator

USAGE:
    mncalc [OPTIONS]

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

OPTIONS:
    -e, --eval <expression>    The expression to evaluate