From 97a0d856b232b21d263ecf226d407334518f6846 Mon Sep 17 00:00:00 2001
From: Zach Dziura <zcdziura@gmail.com>
Date: Wed, 27 May 2015 14:21:03 -0400
Subject: [PATCH] Finished lexer stub

Still need to test...
---
 src/errors.rs |  8 ++++--
 src/lexer.rs  | 80 ++++++++++++++++++++++++++++++++++++++++++---------
 src/lib.rs    |  2 +-
 3 files changed, 72 insertions(+), 18 deletions(-)

diff --git a/src/errors.rs b/src/errors.rs
index d5f2733..ab2ff02 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -22,7 +22,7 @@ use std::fmt::{Display, Formatter, Result};
 pub struct Error {
     kind: ErrorKind,
     offender: String,
-    desc: String,
+    desc: String
 }
 
 impl Error {
@@ -49,15 +49,17 @@ impl Display for Error {
 
 #[derive(Clone, Debug)]
 pub enum ErrorKind {
-    InvalidOption,
+    InvalidArgument,
     MissingArgument,
+    OptionFormat
 }
 
 impl ErrorKind {
     fn description(&self) -> String {
         match *self {
-            ErrorKind::InvalidOption => String::from("An invalid option was passed to the program:"),
+            ErrorKind::InvalidArgument => String::from("An invalid option was passed to the program:"),
             ErrorKind::MissingArgument => String::from("A required argument is missing:"),
+            ErrorKind::OptionFormat => String::from("An option was defined in the wrong format:")
         }
     }
 }
diff --git a/src/lexer.rs b/src/lexer.rs
index a25a5d9..0ba0e10 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -15,35 +15,87 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-use std::fmt::{self, Display, Formatter};
+use std::fmt::{Display, Formatter, Result};
 
-pub fn analyze(input: &str) -> Result {
+use errors::{Error, ErrorKind};
+
+pub fn analyze(input: &str) -> Result<Token, Error> {
+    let mut token = Token::new();
     
+    token.is_arg = match &opt[..1] {
+        ":" => true,
+        _ => false
+    };
+    
+    token.has_arg = match &opt[(opt.len() - 1)..] {
+        ":" => true,
+        _ => false
+    };
+    
+    if token.is_arg && token.has_arg {
+        return Error::new(ErrorKind::OptionFormat, String::from(input));
+    }
+    
+    let option = &input[1..(input.len() - 1)];
+
+    let mut current_stage = AnalysisStage::ShortName;
+    let mut current_char = option.chars().next();
+    while current_char.is_some() {
+        match current_char {
+            '/' => {
+                current_stage = AnalysisStage::LongName;
+                continue;
+            },
+            '(' => {
+                current_stage = AnalysisStage::Description;
+                continue;
+            },
+            ')' => break,
+            _ => ()
+        }
+        
+        match current_stage {
+            ShortName => token.short_name.push(current_char),
+            LongName => token.long_name.push(current_char),
+            Description => token.description.push(current_char)
+        }
+        
+        current_char = current_char.next();
+    }
+    
+    Ok(token)
 }
 
-pub struct Result {
+enum AnalysisStage {
+    ShortName,
+    LongName,
+    Description
+}
+
+pub struct Token {
     short_name: String,
     long_name: String,
     is_arg: bool,
     has_arg: bool,
+    is_group: bool,
     description: String
 }
 
-impl Result {
-    pub fn new(short_name: &str, long_name: &str, is_arg: bool, has_arg: bool, description: &str)
-        -> Result {
-        Result {
-            short_name: String::from(short_name),
-            long_name: String::from(long_name),
-            is_arg: is_arg,
-            has_arg: has_arg,
-            description: String::from(description)
+impl Token {
+    pub fn new() -> Token {
+        Token {
+            short_name: String::new(),
+            long_name: String::new(),
+            is_arg: false,
+            has_arg: false,
+            is_group: false,
+            description: String::new()
         }
     }
 }
 
-impl Display for Result {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+impl Display for Token {
+    fn fmt(&self, f: &mut Formatter) -> Result {
         let repr = format!("-{}, --{}    {}", self.short_name, self.long_name, self.description);
         write(self, "{}", repr)
     }
diff --git a/src/lib.rs b/src/lib.rs
index 4c42714..9fd5271 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -62,7 +62,7 @@ pub fn parse(mut args: Args, options: &[&'static str]) -> Result<Matches, Error>
                     matches.insert(&arg, "");
                 }
             } else {
-                return Err(Error::new(ErrorKind::InvalidOption, arg));
+                return Err(Error::new(ErrorKind::InvalidArgument, arg));
             }
 
         } else { // Probably a required arg