X-Git-Url: https://harishankar.org/repos/?p=evpf.git;a=blobdiff_plain;f=src%2Fmain.rs;h=98532ff4f10a7fdc12d5668af895c7ad083e863c;hp=bab1e521d17a5e4f2e794d645f851c2b448c0d01;hb=a550442ff655e75c85edc1d0d591c34a1cc4380c;hpb=ac6c2056e35e042ada5f88580329bc2ca51e72ff

diff --git a/src/main.rs b/src/main.rs
index bab1e52..98532ff 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,8 +1,8 @@
 use std::io;
 use std::io::Write;
 use regex::Regex;
-use ansi_term::Colour;
-use ansi_term::Style;
+use colored::*;
+use std::env;
 
 const ILLEGAL_EXP : &'static str = "Illegal Expression";
 const ERR_PARSING_NOT_MATCH : &'static str = "Error parsing expression! \
@@ -134,49 +134,86 @@ fn evaluate (expr : &str, match_num : &regex::Regex) -> Result<f32,String> {
 }
 
 fn main() {
-	// get a line from input and evaluate it 
-	let mut expr = String::new ();
+
+	let args : Vec<String> = env::args().collect ();
 	// regular expression to match a number 
 	let match_num = Regex::new (r"^\d+?\.*?\d*?$").unwrap ();
-	// loop until a blank line is received	
-	loop {
-		expr.clear ();	
-		print!("{}", Style::new().bold().paint("evpf>"));
-		io::stdout().flush ().expect (ERR_FLUSHING);
-		// read a line of text
-		io::stdin().read_line (&mut expr).expect (ERR_READING_LINE);
-		// trim the text
-		let expr = expr.trim ();
-
-		if expr == "q" || expr == "Q" {
-		// quit if the expression is q or Qs 
-			break;
-		} else if expr == "?" || expr == "h" || expr == "H" {
-		// display help text
-			for text in HELP_TEXT.iter() {
-				println! ("{}", Colour::Cyan.paint(*text));
+	
+	if args.len () > 1 {
+	// if arguments are provided run in command line mode - i.e. print the 
+	// result and exit	
+		let mut expr = String::new ();
+		let mut i = 0;
+		// create the expression string to evaluate
+		for arg in args.iter() {
+			if i > 0 {
+				expr.push_str (&arg);
+				expr.push_str (" ");
 			}
-
-			continue;
-		} else if expr == "" {
-		// continue without proceeding
-			continue;
+			i += 1;
 		}
-		
-		// Evaluate result
+		// evaluate the result 
 		let res = evaluate (&expr, &match_num);
-		
 		// if Result is OK then print the result in green
 		if res.is_ok () {
 			let restxt = format! ("{}: {}", RESULT, 
 											res.unwrap());
-			println! ("{}", Colour::Green.paint (restxt));
+			println! ("{}", restxt.green ());
 		} else {
 		// print the error in purple
 			let errtxt = format! ("{}: {}", ERROR, 
 											res.unwrap_err());
-			eprintln! ("{}", Colour::Purple.paint (errtxt));
-			eprintln! ("{}", Colour::Purple.paint (ERROR_HELP));
+			eprintln! ("{}", errtxt.purple ());
+		}		
+		
+	} else {
+		// if arguments are not provided run in interactive mode - 
+		// display a prompt and get the expression 
+		// repeat until the user quits
+		
+		// get a line from input and evaluate it 
+		let mut expr = String::new ();
+
+		// loop until a blank line is received	
+		loop {
+			expr.clear ();	
+			print!("{}", "evpf>".bold() );
+			io::stdout().flush ().expect (ERR_FLUSHING);
+			// read a line of text
+			io::stdin().read_line (&mut expr).expect (ERR_READING_LINE);
+			// trim the text
+			let expr = expr.trim ();
+
+			if expr == "q" || expr == "Q" {
+			// quit if the expression is q or Qs 
+				break;
+			} else if expr == "?" || expr == "h" || expr == "H" {
+			// display help text
+				for text in HELP_TEXT.iter() {
+					println! ("{}", text.cyan() );
+				}
+
+				continue;
+			} else if expr == "" {
+			// continue without proceeding
+				continue;
+			}
+			
+			// Evaluate result
+			let res = evaluate (&expr, &match_num);
+			
+			// if Result is OK then print the result in green
+			if res.is_ok () {
+				let restxt = format! ("{}: {}", RESULT, 
+												res.unwrap());
+				println! ("{}", restxt.green ());
+			} else {
+			// print the error in purple
+				let errtxt = format! ("{}: {}", ERROR, 
+												res.unwrap_err());
+				eprintln! ("{}", errtxt.purple());
+				eprintln! ("{}", ERROR_HELP.purple());
+			}
 		}
 	}
 }