Add engineering mode

cli/src/main.rs

@@ -1,6 +1,7 @@
 mod output;
 mod repl;
 
+use kalk::kalk_value::ScientificNotationFormat;
 use kalk::parser;
 use seahorse::{App, Context, Flag, FlagType};
 use std::env;
@@ -24,6 +25,10 @@ fn main() {
                 .description("Specify number precision")
                 .alias("p"),
         )
+        .flag(
+            Flag::new("eng", FlagType::Bool)
+                .description("Engineering mode")
+        )
         .flag(
             Flag::new("angle-unit", FlagType::String)
                 .description("Unit used for angles, either rad or deg. This can also be specified using an environment variable with the name 'ANGLE_UNIT'.")
@@ -58,6 +63,12 @@ fn default_action(context: &Context) {
     let precision = context
         .int_flag("precision")
         .unwrap_or(output::DEFAULT_PRECISION as isize) as u32;
+    let format = if context.bool_flag("eng") {
+        ScientificNotationFormat::Engineering
+    } else {
+        ScientificNotationFormat::Normal
+    };
+
     if let Ok(max_recursion_depth) = context.int_flag("max-recursion-depth") {
         parser_context = parser_context.set_max_recursion_depth(max_recursion_depth as u32);
     }
@@ -72,14 +83,15 @@ fn default_action(context: &Context) {
 
     if context.args.is_empty() {
         // REPL
-        repl::start(&mut parser_context, precision);
+        repl::start(&mut parser_context, precision, format);
     } else {
         // Direct output
         output::eval(
             &mut parser_context,
             &context.args.join(" "),
             precision,
             10u8,
+            format,
         );
     }
 }

cli/src/output.rs

@@ -1,9 +1,9 @@
 use ansi_term::Colour::Red;
-use kalk::parser;
+use kalk::{kalk_value::ScientificNotationFormat, parser};
 
 pub(crate) const DEFAULT_PRECISION: u32 = 63;
 
-pub fn eval(parser: &mut parser::Context, input: &str, precision: u32, base: u8) {
+pub fn eval(parser: &mut parser::Context, input: &str, precision: u32, base: u8, format: ScientificNotationFormat) {
     match parser::eval(parser, input, precision) {
         Ok(Some(mut result)) => {
             if !result.set_radix(base) {
@@ -13,7 +13,7 @@ pub fn eval(parser: &mut parser::Context, input: &str, precision: u32, base: u8)
             }
 
             if precision == DEFAULT_PRECISION {
-                println!("{}", result.to_string_pretty());
+                println!("{}", result.to_string_pretty_format(format));
 
                 return;
             }

cli/src/repl.rs

@@ -1,5 +1,6 @@
 use crate::output;
 use ansi_term::Colour::{self, Cyan};
+use kalk::kalk_value::ScientificNotationFormat;
 use kalk::parser;
 use lazy_static::lazy_static;
 use regex::Captures;
@@ -24,7 +25,7 @@ struct Context {
     base: u8,
 }
 
-pub fn start(parser: &mut parser::Context, precision: u32) {
+pub fn start(parser: &mut parser::Context, precision: u32, format: ScientificNotationFormat) {
     let mut editor = Editor::<RLHelper>::new();
     editor.set_helper(Some(RLHelper {
         highlighter: LineHighlighter {},
@@ -66,7 +67,7 @@ pub fn start(parser: &mut parser::Context, precision: u32) {
         match readline {
             Ok(input) => {
                 editor.add_history_entry(input.as_str());
-                eval_repl(&mut repl, parser, &input, precision);
+                eval_repl(&mut repl, parser, &input, precision, format);
             }
             Err(ReadlineError::Interrupted) => break,
             _ => break,
@@ -78,7 +79,7 @@ pub fn start(parser: &mut parser::Context, precision: u32) {
     }
 }
 
-fn eval_repl(repl: &mut self::Context, parser: &mut parser::Context, input: &str, precision: u32) {
+fn eval_repl(repl: &mut self::Context, parser: &mut parser::Context, input: &str, precision: u32, format: ScientificNotationFormat) {
     if let Some(file_name) = input.strip_prefix("load ") {
         if let Some(file_path) = crate::get_input_file_by_name(file_name) {
             crate::load_input_file(&file_path, precision, parser);
@@ -109,7 +110,7 @@ fn eval_repl(repl: &mut self::Context, parser: &mut parser::Context, input: &str
         "clear" => print!("\x1B[2J"),
         "exit" => process::exit(0),
         "help" => print_cli_help(),
-        _ => output::eval(parser, input, precision, repl.base),
+        _ => output::eval(parser, input, precision, repl.base, format),
     }
 }
 

kalk/src/calculation_result.rs

@@ -1,6 +1,6 @@
 use wasm_bindgen::prelude::wasm_bindgen;
 
-use crate::kalk_value::{ComplexNumberType, KalkValue, ScientificNotation};
+use crate::kalk_value::{ComplexNumberType, KalkValue, ScientificNotation, ScientificNotationFormat};
 
 #[wasm_bindgen]
 pub struct CalculationResult {
@@ -36,15 +36,15 @@ impl CalculationResult {
         self.value.to_string_big()
     }
 
-    #[wasm_bindgen(js_name = toPrettyString)]
-    pub fn to_string_pretty(&self) -> String {
+    #[wasm_bindgen(js_name = toPrettyStringWithFormat)]
+    pub fn to_string_pretty_format(&self, format: ScientificNotationFormat) -> String {
         let value = if self.radix == 10 {
-            self.value.to_string_pretty_radix(10)
+            self.value.to_string_pretty_radix(10, format)
         } else {
             format!(
                 "{}\n{}",
-                self.value.to_string_pretty_radix(10),
-                self.value.to_string_pretty_radix(self.radix),
+                self.value.to_string_pretty_radix(10, format),
+                self.value.to_string_pretty_radix(self.radix, format),
             )
         };
 
@@ -55,6 +55,11 @@ impl CalculationResult {
         }
     }
 
+    #[wasm_bindgen(js_name = toPrettyString)]
+    pub fn to_string_pretty(&self) -> String {
+        self.to_string_pretty_format(ScientificNotationFormat::Normal)
+    }
+
     #[wasm_bindgen(js_name = getValue)]
     pub fn to_f64(&self) -> f64 {
         self.value.to_f64()

kalk/src/kalk_value/mod.rs

@@ -2,7 +2,7 @@
 pub mod with_rug;
 
 #[cfg(feature = "rug")]
-use rug::Float;
+use rug::{Float, ops::Pow};
 #[cfg(feature = "rug")]
 pub use with_rug::*;
 
@@ -108,7 +108,6 @@ macro_rules! as_number_or_zero {
 #[wasm_bindgen]
 #[derive(Clone)]
 pub struct ScientificNotation {
-    pub negative: bool,
     pub value: f64,
     pub exponent: i32,
     pub imaginary: bool,
@@ -121,17 +120,42 @@ pub enum ComplexNumberType {
     Imaginary,
 }
 
+#[wasm_bindgen]
+#[derive(Clone, Copy)]
+pub enum ScientificNotationFormat {
+    Normal,
+    Engineering,
+}
+
 #[wasm_bindgen]
 impl ScientificNotation {
     #[wasm_bindgen(js_name = toString)]
     pub fn to_js_string(&self) -> String {
         self.to_string()
     }
+
+    pub fn to_string_format(&self, format: ScientificNotationFormat) -> String {
+        match format {
+            ScientificNotationFormat::Normal => self.to_string(),
+            ScientificNotationFormat::Engineering => self.to_string_eng(),
+        }
+    }
+
+    fn to_string_eng(&self) -> String {
+        let exponent = self.exponent - 1;
+        let modulo = exponent % 3;
+        let value = self.value * 10_f64.powi(modulo);
+
+        ScientificNotation {
+            value,
+            exponent: exponent - modulo + 1,
+            imaginary: self.imaginary,
+        }.to_string()
+    }
 }
 
 impl std::fmt::Display for ScientificNotation {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let sign = if self.negative { "-" } else { "" };
         let digits_and_mul = if self.value == 1f64 {
             String::new()
         } else {
@@ -140,11 +164,10 @@ impl std::fmt::Display for ScientificNotation {
 
         write!(
             f,
-            "{}{}10^{} {}",
-            sign,
+            "{}10^{}{}",
             digits_and_mul,
             self.exponent - 1,
-            if self.imaginary { "i" } else { "" }
+            if self.imaginary { " i" } else { "" }
         )
     }
 }
@@ -288,7 +311,7 @@ impl KalkValue {
         }
     }
 
-    pub fn to_string_pretty_radix(&self, radix: u8) -> String {
+    pub fn to_string_pretty_radix(&self, radix: u8, format: ScientificNotationFormat) -> String {
         let (real, imaginary, unit) = match self {
             KalkValue::Number(real, imaginary, unit) => (real, imaginary, unit),
             _ => return self.to_string(),
@@ -308,21 +331,31 @@ impl KalkValue {
         let mut new_real = real.clone();
         let mut new_imaginary = imaginary.clone();
         let mut has_scientific_notation = false;
-        let result_str = if (-6..8).contains(&sci_notation_real.exponent) || real == &0f64 {
+        let is_engineering_mode = matches!(format, ScientificNotationFormat::Engineering);
+        let result_str = if is_engineering_mode {
+            has_scientific_notation = true;
+
+            sci_notation_real.to_string_format(ScientificNotationFormat::Engineering)
+        } else if (-6..8).contains(&sci_notation_real.exponent) || real == &0f64 {
             self.to_string_real(radix)
         } else if sci_notation_real.exponent <= -14 {
             new_real = float!(0);
+
             String::from("0")
         } else if radix == 10 {
             has_scientific_notation = true;
 
-            sci_notation_real.to_string().trim().to_string()
+            sci_notation_real.to_string_format(format)
         } else {
             return String::new();
         };
 
         let sci_notation_imaginary = self.to_scientific_notation(ComplexNumberType::Imaginary);
-        let result_str_imaginary = if (-6..8).contains(&sci_notation_imaginary.exponent)
+        let result_str_imaginary = if is_engineering_mode {
+            has_scientific_notation = true;
+
+            sci_notation_imaginary.to_string_format(ScientificNotationFormat::Engineering)
+        } else if (-6..8).contains(&sci_notation_imaginary.exponent)
             || imaginary == &0f64
             || imaginary == &1f64
         {
@@ -333,7 +366,7 @@ impl KalkValue {
         } else if radix == 10 {
             has_scientific_notation = true;
 
-            sci_notation_imaginary.to_string().trim().to_string()
+            sci_notation_imaginary.to_string_format(format)
         } else {
             return String::new();
         };
@@ -368,15 +401,15 @@ impl KalkValue {
             if estimate != output && radix == 10 {
                 output.push_str(&format!(" ≈ {}", estimate));
             }
-        } else if has_scientific_notation {
+        } else if has_scientific_notation && !is_engineering_mode {
             output.insert_str(0, &format!("{} ≈ ", self));
         }
 
         output
     }
 
-    pub fn to_string_pretty(&self) -> String {
-        self.to_string_pretty_radix(10)
+    pub fn to_string_pretty(&self, format: ScientificNotationFormat) -> String {
+        self.to_string_pretty_radix(10, format)
     }
 
     pub fn to_string_with_unit(&self) -> String {
@@ -516,7 +549,6 @@ impl KalkValue {
         let exponent = value.abs().log10().floor() as i32 + 1;
 
         ScientificNotation {
-            negative: value < 0f64,
             value: value / (10f64.powf(exponent as f64 - 1f64) as f64),
             // I... am not sure what else to do...
             exponent,
@@ -1309,7 +1341,6 @@ fn pow(x: f64, y: f64) -> f64 {
 
 #[cfg(feature = "rug")]
 fn pow(x: Float, y: Float) -> Float {
-    use rug::ops::Pow;
     x.pow(y)
 }
 
@@ -1377,9 +1408,11 @@ impl From<i32> for KalkValue {
 
 #[cfg(test)]
 mod tests {
-    use crate::kalk_value::{spaced, KalkValue};
+    use crate::kalk_value::{spaced, KalkValue, ScientificNotationFormat};
     use crate::test_helpers::cmp;
 
+    use super::ScientificNotation;
+
     #[test]
     fn test_spaced() {
         assert_eq!(spaced("1"), String::from("1"));
@@ -1543,8 +1576,30 @@ mod tests {
             (float!(3.00000000004), float!(0.0), "3"),
         ];
         for (real, imaginary, output) in in_out {
-            let result = KalkValue::Number(real, imaginary, None).to_string_pretty();
+            let result = KalkValue::Number(real, imaginary, None).to_string_pretty(ScientificNotationFormat::Normal);
             assert_eq!(output, result);
         }
     }
+
+    #[test]
+    fn test_eng_mode() {
+        let in_out = vec![
+            (1.23, 0, "1.23×10^0"),
+            (1.23, 1, "12.3×10^0"),
+            (1.23, 2, "123×10^0"),
+            (1.23, 3, "1.23×10^3"),
+            (1.23, 4, "12.3×10^3"),
+            (1.23, 5, "123×10^3"),
+            (1.23, 6, "1.23×10^6"),
+        ];
+        for (value, exponent, output) in in_out {
+            let sci = ScientificNotation {
+                value,
+                exponent: exponent + 1,
+                imaginary: false,
+            };
+
+            assert_eq!(sci.to_string_format(ScientificNotationFormat::Engineering), output);
+        }
+    }
 }