serafim/calc

Maintainers

Details

github.com/SerafimArts/Calculator

Source

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Installs: 23

Dependents: 0

Suggesters: 0

Security: 0

Stars: 15

Watchers: 3

Forks: 1

Open Issues: 1

3.2.0 2024-04-08 10:05 UTC

Requires

Requires (Dev)

MIT 2d32e54032bd0a8b952a575d81ea54f1085eba61

This package is auto-updated.

Last update: 2024-12-08 11:31:44 UTC

README

Why?

This repository is designed as an example of how you can implement a calculator based on abstract syntax tree generated by the LL(k) recurrence recursive descent parser.

As a grammar used the basic implementation with operators associativity, and not vulnerable to left recursion:

{
  tokens = [
    T_FLOAT = "regexp:\d+\.\d+"
    T_INT   = "regexp:\d+"
  ]
}

<expr>           ::= <addition> | <subtraction> | <term>

<term>           ::= <multiplication> | <division> | <factor>
<factor>         ::= "(" <expr> ")" | <value>

<subtraction>    ::= <term> "-" <expr>
<addition>       ::= <term> "+" <expr>
<multiplication> ::= <factor> "*" <term>
<division>       ::= <factor> ("/" | "รท") <term>

<value>          ::= T_FLOAT | T_INT

Example

Command Line Interface

$ php ./bin/cc run

image

image

Usage

Global:

$ composer global require serafim/calc
$ cc run

Local:

$ composer require serafim/calc
$ ./vendor/bin/cc run