From cc43ffd135c60e09c72dfe872bd7a53dd6baa88f Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Mon, 26 Jun 2017 21:54:57 -0700
Subject: [PATCH] [lexer] Lexer emits Lexes instead of Tokens

---
 lexer/src/lib.rs             | 27 ++++++++++++++++-----------
 lexer/src/token.rs           | 25 +++++++++++++++++++++++++
 lexer/tests/single_tokens.rs | 11 +++++++----
 3 files changed, 48 insertions(+), 15 deletions(-)
 create mode 100644 lexer/src/token.rs

diff --git a/lexer/src/lib.rs b/lexer/src/lib.rs
index 279e40d..70de94f 100644
--- a/lexer/src/lib.rs
+++ b/lexer/src/lib.rs
@@ -3,18 +3,16 @@
  */
 
 use std::iter::Peekable;
+use chars::Lexable;
 
 mod chars;
 mod error;
+mod token;
 
 pub use error::Error;
+pub use token::{Lex, Token};
 
-use chars::Lexable;
-
-pub type Result = std::result::Result<Token, Error>;
-
-#[derive(Debug, Eq, PartialEq)]
-pub enum Token { LeftParen, RightParen, Id(String), }
+pub type Result = std::result::Result<Lex, Error>;
 
 #[derive(Debug, Eq, PartialEq)]
 enum Resume { Here, AtNext } 
@@ -72,8 +70,14 @@ impl<T> Iterator for Lexer<T> where T: Iterator<Item=char> {
             let peek = self.input.peek().map(char::clone);
             let result = if buffer.is_empty() {
                 match peek {
-                    Some(c) if c.is_left_paren() => self.emit(Token::LeftParen, Resume::AtNext),
-                    Some(c) if c.is_right_paren() => self.emit(Token::RightParen, Resume::AtNext),
+                    Some(c) if c.is_left_paren() => {
+                        buffer.push(c);
+                        self.emit(Token::LeftParen, Resume::AtNext)
+                    },
+                    Some(c) if c.is_right_paren() => {
+                        buffer.push(c);
+                        self.emit(Token::RightParen, Resume::AtNext)
+                    },
                     Some(c) if c.is_whitespace() => {
                         self.handle_whitespace(c);
                         IterationResult::Continue
@@ -94,12 +98,12 @@ impl<T> Iterator for Lexer<T> where T: Iterator<Item=char> {
                         IterationResult::Continue
                     }
                     Some(c) if c.is_identifier_delimiter() =>
-                        self.emit(Token::Id(buffer.clone()), Resume::Here),
+                        self.emit(Token::Id, Resume::Here),
                     Some(c) => self.fail(format!("Invalid character: {}", c)),
                     // Found EOF. Emit what we have and finish.
                     // Note: the Resume argument doesn't matter in this case since the input
                     // iterator will always be None from here on.
-                    None => self.emit(Token::Id(buffer.clone()), Resume::Here),
+                    None => self.emit(Token::Id, Resume::Here),
                 }
             };
             match result {
@@ -109,7 +113,8 @@ impl<T> Iterator for Lexer<T> where T: Iterator<Item=char> {
                     if resume == Resume::AtNext {
                         self.input.next();
                     }
-                    return Some(Ok(token))
+                    let lex = Lex::new(token, &buffer, self.line, self.offset);
+                    return Some(Ok(lex))
                 },
                 IterationResult::Error(err) => return Some(Err(err)),
             };
diff --git a/lexer/src/token.rs b/lexer/src/token.rs
new file mode 100644
index 0000000..fda26fc
--- /dev/null
+++ b/lexer/src/token.rs
@@ -0,0 +1,25 @@
+/* lexer/src/token.rs
+ * Eryn Wells <eryn@erynwells.me>
+ */
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct Lex {
+    token: Token,
+    value: String,
+    line: usize,
+    offset: usize,
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub enum Token { LeftParen, RightParen, Id, }
+
+impl Lex {
+    pub fn new(token: Token, value: &str, line: usize, offset: usize) -> Lex {
+        Lex {
+            token: token,
+            value: String::from(value),
+            line: line,
+            offset: offset,
+        }
+    }
+}
diff --git a/lexer/tests/single_tokens.rs b/lexer/tests/single_tokens.rs
index bbfc724..ef05b7c 100644
--- a/lexer/tests/single_tokens.rs
+++ b/lexer/tests/single_tokens.rs
@@ -6,25 +6,28 @@
 
 extern crate sibillexer;
 
-use sibillexer::{Lexer, Token};
+use sibillexer::{Lexer, Lex, Token};
 
 #[test]
 fn lexer_finds_left_paren() {
+    let expected_lex = Lex::new(Token::LeftParen, "(", 0, 0);
     let mut lex = Lexer::new("(".chars());
-    assert_eq!(lex.next(), Some(Ok(Token::LeftParen)));
+    assert_eq!(lex.next(), Some(Ok(expected_lex)));
     assert_eq!(lex.next(), None);
 }
 
 #[test]
 fn lexer_finds_right_paren() {
+    let expected_lex = Lex::new(Token::RightParen, ")", 0, 0);
     let mut lex = Lexer::new(")".chars());
-    assert_eq!(lex.next(), Some(Ok(Token::RightParen)));
+    assert_eq!(lex.next(), Some(Ok(expected_lex)));
     assert_eq!(lex.next(), None);
 }
 
 #[test]
 fn lexer_finds_id() {
+    let expected_lex = Lex::new(Token::Id, "abc", 0, 0);
     let mut lex = Lexer::new("abc".chars());
-    assert_eq!(lex.next(), Some(Ok(Token::Id("abc".to_string()))));
+    assert_eq!(lex.next(), Some(Ok(expected_lex)));
     assert_eq!(lex.next(), None);
 }