gave context items module structure, moved context build to a new method, and implemented empty and set flags

src/context/mod.rs

@@ -0,0 +1,4 @@
+
+pub mod global;
+pub mod helper;
+

src/flag.rs

@@ -2,5 +2,6 @@
 pub const EMPTY_CONTEXT:	[&str;2]	=	[ "-E", "--empty"];
 pub const HELP:				[&str;2]	=	[ "-h", "--help" ];
 pub const QUIET:			[&str;2]	=	[ "-q", "--quiet" ];
+pub const SET:				&str		=	"--set";
 pub const VERSION:			[&str;2]	=	[ "-V", "--version" ];
 

src/main.rs

@@ -9,7 +9,6 @@ use std::{
 };
 
 use evalexpr::{
-	context_map,
 	eval_with_context_mut,
 	ContextWithMutableVariables,
 	HashMapContext,
@@ -21,9 +20,9 @@ use termion::{
 	style
 };
 
+mod context;
+mod eval;
 mod flag;
-mod global;
-mod helper;
 mod util;
 
 pub const VERSION: &str = env!("CARGO_PKG_VERSION");
@@ -41,38 +40,7 @@ fn main() {
 		return;
 	}
 
-	//	build context and handle empty flag
-	let mut context =
-		if !args.contains(flag::EMPTY_CONTEXT) {
-			context_map! {
-				//	globals
-				"c"		=>	global::LIGHT_SPEED,
-				"e"		=>	global::EULER,
-				"phi"	=>	global::GOLDEN_RATIO,
-				"pi"	=>	global::PI,
-				"√2"	=>	global::ROOT_TWO,
-
-				//	math functions
-				"fix"	=>	Function::new(|arg| helper::fix(arg)),
-				"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)),
-
-				//	radix functions
-				"bin"	=>	Function::new(|arg| helper::binary(arg)),
-				"hex"	=>	Function::new(|arg| helper::hexadecimal(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()
-		} else {
-			HashMapContext::new()
-		};
+	let mut context = util::build_context(&mut args);
 
 	//	collect args and evaluate if present
 	let expressions = args.finish();

src/util.rs

@@ -1,7 +1,12 @@
-use evalexpr::{
-	Value,
 
-	EvalexprError
+use evalexpr::{
+	context_map, ContextWithMutableVariables, EvalexprError, HashMapContext, Value
+};
+use pico_args::Arguments;
+
+use crate::{
+	context::{ global, helper },
+	flag
 };
 
 pub(crate) fn parse_radix(prefix: &str, base: u32, arg: &Value) -> Result<Value, EvalexprError> {
@@ -16,3 +21,53 @@ pub(crate) fn parse_radix(prefix: &str, base: u32, arg: &Value) -> Result<Value,
 
 	return Ok(result.unwrap().into());
 }
+
+pub(crate) fn build_context(args: &mut Arguments) -> HashMapContext {
+	let mut output =
+		if !args.contains(flag::EMPTY_CONTEXT) {
+			context_map! {
+				//	globals
+				"c"		=>	global::LIGHT_SPEED,
+				"e"		=>	global::EULER,
+				"phi"	=>	global::GOLDEN_RATIO,
+				"pi"	=>	global::PI,
+				"√2"	=>	global::ROOT_TWO,
+
+				//	math functions
+				"fix"	=>	Function::new(|arg| helper::fix(arg)),
+				"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)),
+
+				//	radix functions
+				"bin"	=>	Function::new(|arg| helper::binary(arg)),
+				"hex"	=>	Function::new(|arg| helper::hexadecimal(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()
+		} else { HashMapContext::new() };
+
+	while let Ok(value) = args.value_from_str::<&str, String>(flag::SET) {
+		let split: Vec<&str> = value.split('=').collect();
+		if split.len() == 2 {
+			let key = split[0].to_owned();
+
+			let value_str = split[1];
+			let value =
+				if let Ok(integer) = value_str.parse::<i64>() { Value::Int(integer) }
+				else if let Ok(float) = value_str.parse::<f64>() { Value::Float(float) }
+				else { Value::from(value_str) };
+
+			output.set_value(key, value).ok(); }
+		else { std::process::exit(1); }
+	}
+
+	output
+}
+