added more globals and functions

src/global.rs

@@ -1,3 +1,6 @@
 
-pub const EULER: f64	=	2.718;
-pub const PI: f64		=	3.14;
+pub const EULER: f64		=	2.718281828459045;
+pub const GOLDEN_RATIO: f64	=	1.618033988749895;
+pub const PI: f64			=	3.141592653589793;
+pub const ROOT_TWO: f64		=	1.414213562373095;
+

src/helper.rs

@@ -6,6 +6,58 @@ use evalexpr::{
 
 use crate::util;
 
+//	Mathematics
+pub fn logarithm(arg: &Value) -> Result<Value, EvalexprError> {
+	let arguments: Vec<Value>;
+	let count: usize;
+	if arg.is_tuple() {
+		arguments = arg.as_tuple()?;
+		count = arguments.len();
+	} else if arg.is_float() {
+		arguments = vec!(arg.as_float()?.into());
+		count = 1;
+	} else if arg.is_int() {
+		arguments = vec!((arg.as_int()? as f64).into());
+		count = 1;
+	} else {
+		return Err(EvalexprError::CustomMessage("Expected numbers".to_string()));
+	}
+
+	let output: Value;
+	match count {
+		1 => {
+			let argument = &arguments[0];
+			if !argument.is_number() {
+				return Err(EvalexprError::CustomMessage("Expected number".to_string()));
+			}
+			let number = if argument.is_float() { argument.as_float()? } else { argument.as_int()? as f64 };
+			output = number.ln().into();
+		},
+		2 => {
+			let arg_value = &arguments[0];
+			let arg_base = &arguments[1];
+			if !(arg_value.is_number() && arg_base.is_number()) {
+				return Err(EvalexprError::CustomMessage("Expected two numbers".to_string()));
+			}
+			let value: f64 = if arg_value.is_float() { arg_value.as_float()? } else { arg_value.as_int()? as f64 };
+			let base: f64 = if arg_base.is_float() { arg_base.as_float()? } else { arg_base.as_int()? as f64 };
+			output = value.log(base).into();
+		},
+		_ => {
+			return Err(EvalexprError::WrongFunctionArgumentAmount { expected: 2, actual: count });
+		}
+	}
+	return Ok(output);
+}
+
+pub fn square_root(arg: &Value) -> Result<Value, EvalexprError> {
+	if !arg.is_number() {
+		return Err(EvalexprError::CustomMessage("Expected a number.".to_string()));
+	}
+	let value: f64 = if arg.is_float() { arg.as_float()? } else { arg.as_int()? as f64 };
+	return Ok(value.sqrt().into());
+}
+
 //	Data Science
 pub fn average(arg: &Value) -> Result<Value, EvalexprError> {
 	let arguments = arg.as_tuple()?;

src/main.rs

@@ -14,7 +14,9 @@ use evalexpr::{
 	eval_with_context_mut,
 
 	HashMapContext,
-	Value
+	Value,
+
+	Context
 };
 use termion::{
 	color,
@@ -25,13 +27,19 @@ mod global;
 mod helper;
 mod util;
 
-pub const VERSION: &str = "0.1.5";
+pub const VERSION: &str = "0.2.0";
 
 fn main() {
 	let mut context = context_map! {
 		//	globals
 		"e"		=>	global::EULER,
+		"phi"	=>	global::GOLDEN_RATIO,
 		"pi"	=>	global::PI,
+		"√2"	=>	global::ROOT_TWO,
+
+		//	math functions
+		"log"	=>	Function::new(|arg| helper::logarithm(arg)),
+		"sqrt"	=>	Function::new(|arg| helper::square_root(arg)),
 
 		//	data science functions
 		"avg"	=>	Function::new(|arg| helper::average(arg)),
@@ -39,7 +47,12 @@ fn main() {
 		//	radix functions
 		"bin"	=>	Function::new(|arg| helper::binary(arg)),
 		"hex"	=>	Function::new(|arg| helper::hexadecimal(arg)),
-		"oct" => Function::new(|arg| helper::octal(arg))
+		"oct"	=>	Function::new(|arg| helper::octal(arg)),
+
+		//	character aliases
+		"ϕ"		=>	global::GOLDEN_RATIO,
+		"π"		=>	global::PI,
+		"√"		=>	Function::new(|arg| helper::square_root(arg))
 	}.unwrap();
 	let expressions: Vec<String> = env::args().skip(1).collect();
 	if expressions.len() == 0 {