aboutsummaryrefslogtreecommitdiff
path: root/src/main.rs
blob: ffdb690ac6ed05e3d655432420d5f8c44cc06803 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
/*
 *  eva - an easy to use calculator REPL similar to bc(1)
 *  Copyright (C) 2019  Akshay Oppiliappan <[email protected]>
 *
 */

// std
use std::f64;

// modules
mod lex;
use crate::lex::*;
mod parse;
use crate::parse::*;
mod error;
use crate::error::{ CalcError, handler };
mod format;
use crate::format::*;

// extern crates
use rustyline::error::ReadlineError;
use rustyline::Editor;
use rustyline::config::{ Builder, ColorMode, EditMode, CompletionType };
use rustyline::highlight::{ Highlighter, MatchingBracketHighlighter };
use rustyline::hint::{ Hinter, HistoryHinter };
use clap::{Arg, App};
use lazy_static::lazy_static;

struct LineHelper (MatchingBracketHighlighter, HistoryHinter);

struct Configuration {
    radian_mode: bool,
    fix: usize,
    base: usize,
    input: String
}

lazy_static! {
    static ref CONFIGURATION: Configuration =  parse_arguments();
}

fn main() {
    if CONFIGURATION.input.len() > 0 {
        let evaled = eval_math_expression(&CONFIGURATION.input[..]);
        match evaled {
            Ok(ans) => pprint(ans),
            Err(e) => {
                eprintln!("{}", handler(e));
                std::process::exit(1);
            },
        };
    } else {
        let config_builder = Builder::new();
        let config = config_builder.color_mode(ColorMode::Enabled)
            .edit_mode(EditMode::Emacs)
            .history_ignore_space(true)
            .completion_type(CompletionType::Circular)
            .max_history_size(1000)
            .build();
        let mut rl = Editor::<()>::with_config(config);
        if rl.load_history("history.txt").is_err() {
            println!("No previous history.");
        }

        loop {
            let readline = rl.readline("> ");
            match readline {
                Ok(line) => {
                    rl.add_history_entry(line.as_ref());
                    let evaled = eval_math_expression(&line[..]);
                    match evaled {
                        Ok(ans) => pprint(ans),
                        Err(e) => println!("{}", handler(e)),
                    };
                },
                Err(ReadlineError::Interrupted) => {
                    println!("CTRL-C");
                    break
                },
                Err(ReadlineError::Eof) => {
                    println!("CTRL-D");
                    break
                },
                Err(err) => {
                    println!("Error: {:?}", err);
                    break
                }
            }
        }
        rl.save_history("history.txt").unwrap();
    }
}

fn parse_arguments() -> Configuration {
    let config = App::new(env!("CARGO_PKG_NAME"))
        .version(env!("CARGO_PKG_VERSION"))
        .author(env!("CARGO_PKG_AUTHORS"))
        .about(env!("CARGO_PKG_DESCRIPTION"))
        .arg(Arg::with_name("fix")
             .short("f")
             .long("fix")
             .takes_value(true)
             .value_name("FIX")
             .help("set number of decimal places in the output"))
        .arg(Arg::with_name("base")
             .short("b")
             .long("base")
             .takes_value(true)
             .value_name("RADIX")
             .help("set the radix of calculation output (1 - 36)"))
        .arg(Arg::with_name("INPUT")
             .help("optional expression string to run eva in command mode")
             .index(1))
        .arg(Arg::with_name("radian")
             .short("r")
             .long("radian")
             .help("set eva to radian mode"))
        .get_matches();

    let mut input = String::new();
    if let Some(i) = config.value_of("INPUT") {
        input.push_str(i);
    };
    Configuration {
        radian_mode: config.is_present("radian"),
        fix: config.value_of("fix")
            .unwrap_or("10")
            .parse()
            .unwrap(),
        base: config.value_of("base")
            .unwrap_or("10")
            .parse()
            .unwrap(),
        input,
    }
}


fn eval_math_expression(input: &str) -> Result<f64, CalcError> {
    let input = input.trim();
    let input = input.replace(" ", "");
    if input.len() == 0 {
        return Ok(0.)
    }
    let input        = format::autobalance_parens(&input[..])?;
    let lexed        = lexer(&input[..])?;
    let postfixed    = to_postfix(lexed)?;
    let evaled       = eval_postfix(postfixed)?;
    let evaled_fixed = format!("{:.*}", CONFIGURATION.fix, evaled).parse::<f64>().unwrap();
    Ok(evaled_fixed)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn basic_ops() {
        let evaled = eval_math_expression("6*2 + 3 + 12 -3").unwrap();
        assert_eq!(24., evaled);
    }
    #[test]
    fn trignometric_fns() {
        let evaled = eval_math_expression("sin(30) + tan(45").unwrap();
        assert_eq!(1.5, evaled);
    }
    #[test]
    fn brackets() {
        let evaled = eval_math_expression("(((1 + 2 + 3) ^ 2 ) - 4)").unwrap();
        assert_eq!(32., evaled);
    }
    #[test]
    fn floating_ops() {
        let evaled = eval_math_expression("1.2816 + 1 + 1.2816/1.2").unwrap();
        assert_eq!(3.3496, evaled);
    }
    #[test]
    fn inverse_trignometric_fns() {
        let evaled = eval_math_expression("deg(asin(1) + acos(1))").unwrap();
        assert_eq!(90., evaled);
    }
}