FEATURE: Use context for our error reporting.

Cargo.lock

@@ -1,6 +1,6 @@
 [[package]]
 name = "abortable_parser"
-version = "0.1.0"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -228,7 +228,7 @@ dependencies = [
 name = "ucg"
 version = "0.2.0"
 dependencies = [
- "abortable_parser 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "abortable_parser 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bencher 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.26.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "cpuprofiler 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -285,7 +285,7 @@ dependencies = [
 ]
 
 [metadata]
-"checksum abortable_parser 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a628e31269165eeea62b71b2555c6379d4fbadb3e34656b6e1445b0235247c0d"
+"checksum abortable_parser 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bd280856ce341823c6aa6fddb3bafae236c23223824f47aef3443deb0b8d900c"
 "checksum ansi_term 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "23ac7c30002a5accbf7e8987d0632fa6de155b7c3d39d0067317a391e00a2ef6"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
 "checksum backtrace 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "346d7644f0b5f9bc73082d3b2236b69a05fd35cce0cfa3724e184e6a5c9e2a2f"

Cargo.toml

@@ -10,7 +10,7 @@ keywords    = ["compiler", "config"]
 license     = "Apache-2.0"
 
 [dependencies]
-abortable_parser = "~0.1.0"
+abortable_parser = "~0.2.0"
 clap         = "~2.26.0"
 serde_json   = "~1.0.9"
 simple-error = "0.1"

src/error.rs

@@ -81,7 +81,6 @@ impl Error {
         cause: Box<error::Error>,
         pos: Position,
     ) -> Self {
-        // FIXME(jwall): This should take a real position instead of this fake one.
         let mut e = Self::new(msg, t, pos);
         e.cause = Some(cause);
         return e;

src/parse/mod.rs

@@ -28,6 +28,7 @@ use error;
 use iter::OffsetStrIter;
 use tokenizer::*;
 
+// TODO(jwall): Rename this to something better.
 type NomResult<'a, O> = Result<SliceIter<'a, Token>, O>;
 
 #[cfg(feature = "tracing")]
@@ -35,7 +36,7 @@ const ENABLE_TRACE: bool = true;
 #[cfg(not(feature = "tracing"))]
 const ENABLE_TRACE: bool = false;
 
-type ParseResult<O> = std::result::Result<O, abortable_parser::Error>;
+type ParseResult<'a, O> = std::result::Result<O, abortable_parser::Error<SliceIter<'a, Token>>>;
 
 macro_rules! trace_nom {
     ($i:expr, $rule:ident!( $($args:tt)* )) => {
@@ -94,7 +95,10 @@ make_fn!(
 );
 
 // Helper function to make the return types work for down below.
-fn triple_to_number(v: (Option<Token>, Option<Token>, Option<Token>)) -> ParseResult<Value> {
+fn triple_to_number<'a>(
+    input: SliceIter<'a, Token>,
+    v: (Option<Token>, Option<Token>, Option<Token>),
+) -> ParseResult<'a, Value> {
     let (pref, mut pref_pos) = match v.0 {
         None => ("", Position::new(0, 0, 0)),
         Some(ref bs) => (bs.fragment.borrow(), bs.pos.clone()),
@@ -106,7 +110,10 @@ fn triple_to_number(v: (Option<Token>, Option<Token>, Option<Token>)) -> ParseRe
         let i = match FromStr::from_str(pref) {
             Ok(i) => i,
             Err(_) => {
-                return Err(Error::new(format!("Not an integer! {}", pref), &0));
+                return Err(Error::new(
+                    format!("Not an integer! {}", pref),
+                    Box::new(input.clone()),
+                ));
             }
         };
         return Ok(Value::Int(value_node!(i, pref_pos)));
@@ -116,9 +123,9 @@ fn triple_to_number(v: (Option<Token>, Option<Token>, Option<Token>)) -> ParseRe
         pref_pos = v.1.unwrap().pos;
     }
 
-    let (suf, pos) = match v.2 {
-        None => ("".to_string(), Position::new(0, 0, 0)),
-        Some(bs) => (bs.fragment, bs.pos),
+    let suf = match v.2 {
+        None => "".to_string(),
+        Some(bs) => bs.fragment,
     };
 
     let to_parse = pref.to_string() + "." + &suf;
@@ -127,7 +134,7 @@ fn triple_to_number(v: (Option<Token>, Option<Token>, Option<Token>)) -> ParseRe
         Err(_) => {
             return Err(Error::new(
                 format!("Not a float! {}", to_parse),
-                &pos.offset,
+                Box::new(input.clone()),
             ));
         }
     };
@@ -212,7 +219,6 @@ macro_rules! alt_peek {
     // This is our default termination case.
     // If there is no fallback then we return an Error.
     (__inner $i:expr, __end) => {
-        // FIXME(jwall): Should we make this a compile error instead?
         compile_error!("alt_peek! requirs a fallback case");
     };
 
@@ -270,10 +276,13 @@ fn number(input: SliceIter<Token>) -> Result<SliceIter<Token>, Value> {
         Result::Abort(e) => Result::Abort(e),
         Result::Fail(e) => Result::Fail(e),
         Result::Incomplete(offset) => Result::Incomplete(offset),
-        Result::Complete(rest, triple) => match triple_to_number(triple) {
+        Result::Complete(rest, triple) => {
+            let num = triple_to_number(rest.clone(), triple);
+            match num {
                 Ok(val) => Result::Complete(rest, val),
                 Err(e) => Result::Fail(e),
-        },
+            }
+        }
     }
 }
 // trace_macros!(false);
@@ -415,7 +424,7 @@ fn symbol_or_expression(input: SliceIter<Token>) -> NomResult<Expression> {
                     } else {
                         return Result::Fail(Error::new(
                             "Expected (.) but no dot found".to_string(),
-                            &rest,
+                            Box::new(rest.clone()),
                         ));
                     }
                 }
@@ -425,7 +434,7 @@ fn symbol_or_expression(input: SliceIter<Token>) -> NomResult<Expression> {
                     } else {
                         return Result::Fail(Error::new(
                             "Expected (.) but no dot found".to_string(),
-                            &rest,
+                            Box::new(rest.clone()),
                         ));
                     }
                 }
@@ -471,7 +480,7 @@ fn selector_list(input: SliceIter<Token>) -> NomResult<SelectorList> {
         if list.is_empty() {
             return Result::Fail(Error::new(
                 "(.) with no selector fields after".to_string(),
-                &rest,
+                Box::new(rest.clone()),
             ));
         } else {
             (rest, Some(list))
@@ -514,7 +523,12 @@ make_fn!(
     )
 );
 
-fn tuple_to_macro(pos: Position, vals: Option<Vec<Value>>, val: Value) -> ParseResult<Expression> {
+fn tuple_to_macro<'a>(
+    input: SliceIter<'a, Token>,
+    pos: Position,
+    vals: Option<Vec<Value>>,
+    val: Value,
+) -> ParseResult<'a, Expression> {
     let mut default_args = match vals {
         None => Vec::new(),
         Some(vals) => vals,
@@ -533,7 +547,7 @@ fn tuple_to_macro(pos: Position, vals: Option<Vec<Value>>, val: Value) -> ParseR
         })),
         val => Err(Error::new(
             format!("Expected Tuple Got {:?}", val),
-            &val.pos().offset,
+            Box::new(input.clone()),
         )),
     }
 }
@@ -558,34 +572,42 @@ fn macro_expression(input: SliceIter<Token>) -> Result<SliceIter<Token>, Express
         Result::Abort(e) => Result::Abort(e),
         Result::Fail(e) => Result::Fail(e),
         Result::Incomplete(offset) => Result::Incomplete(offset),
-        Result::Complete(rest, (pos, arglist, map)) => match tuple_to_macro(pos, arglist, map) {
+        Result::Complete(rest, (pos, arglist, map)) => {
+            match tuple_to_macro(rest.clone(), pos, arglist, map) {
                 Ok(expr) => Result::Complete(rest, expr),
-            Err(e) => Result::Fail(Error::caused_by("Invalid Macro syntax", &rest, Box::new(e))),
-        },
+                Err(e) => Result::Fail(Error::caused_by(
+                    "Invalid Macro syntax",
+                    Box::new(e),
+                    Box::new(rest.clone()),
+                )),
+            }
+        }
     }
 }
 
-// FIXME(jwall): need to make this into a proper parse function.
-fn tuple_to_select(
-    pos: Position,
+fn tuple_to_select<'a>(
+    input: SliceIter<'a, Token>,
     e1: Expression,
     e2: Expression,
     val: Value,
-) -> ParseResult<Expression> {
+) -> ParseResult<'a, Expression> {
     match val {
         Value::Tuple(v) => Ok(Expression::Select(SelectDef {
             val: Box::new(e1),
             default: Box::new(e2),
             tuple: v.val,
-            pos: pos,
+            pos: (&input).into(),
         })),
-        val => Err(Error::new(format!("Expected Tuple Got {:?}", val), &0)),
+        val => Err(Error::new(
+            format!("Expected Tuple Got {:?}", val),
+            Box::new(input.clone()),
+        )),
     }
 }
 
 fn select_expression(input: SliceIter<Token>) -> Result<SliceIter<Token>, Expression> {
     let parsed = do_each!(input,
-        start => word!("select"),
+        _ => word!("select"),
         val => do_each!(
             expr => trace_nom!(expression),
             _ => punct!(","),
@@ -597,19 +619,19 @@ fn select_expression(input: SliceIter<Token>) -> Result<SliceIter<Token>, Expres
             (expr)
         ),
         map => trace_nom!(tuple),
-        (start.pos.clone(), val, default, map)
+        (val, default, map)
     );
     match parsed {
         Result::Abort(e) => Result::Abort(e),
         Result::Fail(e) => Result::Fail(e),
         Result::Incomplete(offset) => Result::Incomplete(offset),
-        Result::Complete(rest, (pos, val, default, map)) => {
-            match tuple_to_select(pos, val, default, map) {
+        Result::Complete(rest, (val, default, map)) => {
+            match tuple_to_select(input.clone(), val, default, map) {
                 Ok(expr) => Result::Complete(rest, expr),
                 Err(e) => Result::Fail(Error::caused_by(
                     "Invalid Select Expression",
-                    &rest,
                     Box::new(e),
+                    Box::new(rest.clone()),
                 )),
             }
         }
@@ -636,17 +658,21 @@ make_fn!(
     )
 );
 
-fn tuple_to_call(pos: Position, val: Value, exprs: Vec<Expression>) -> ParseResult<Expression> {
+fn tuple_to_call<'a>(
+    input: SliceIter<'a, Token>,
+    val: Value,
+    exprs: Vec<Expression>,
+) -> ParseResult<'a, Expression> {
     if let Value::Selector(def) = val {
         Ok(Expression::Call(CallDef {
             macroref: def,
             arglist: exprs,
-            pos: pos,
+            pos: (&input).into(),
         }))
     } else {
         Err(Error::new(
             format!("Expected Selector Got {:?}", val),
-            &val.pos().offset,
+            Box::new(input.clone()),
         ))
     }
 }
@@ -664,30 +690,34 @@ make_fn!(
 );
 
 fn call_expression(input: SliceIter<Token>) -> Result<SliceIter<Token>, Expression> {
-    let parsed = do_each!(input,
+    let parsed = do_each!(input.clone(),
         macroname => trace_nom!(selector_value),
         _ => punct!("("),
         args => separated!(punct!(","), trace_nom!(expression)),
         _ => punct!(")"),
-        (macroname.pos().clone(), macroname, args)
+        (macroname, args)
     );
     match parsed {
         Result::Abort(e) => Result::Abort(e),
         Result::Fail(e) => Result::Fail(e),
         Result::Incomplete(offset) => Result::Incomplete(offset),
-        Result::Complete(rest, (pos, name, args)) => match tuple_to_call(pos, name, args) {
+        Result::Complete(rest, (name, args)) => match tuple_to_call(input.clone(), name, args) {
             Ok(expr) => Result::Complete(rest, expr),
-            Err(e) => Result::Fail(Error::caused_by("Invalid Call Syntax", &rest, Box::new(e))),
+            Err(e) => Result::Fail(Error::caused_by(
+                "Invalid Call Syntax",
+                Box::new(e),
+                Box::new(rest),
+            )),
         },
     }
 }
 
-fn tuple_to_list_op(
-    pos: Position,
+fn tuple_to_list_op<'a>(
+    input: &'a SliceIter<Token>,
     kind: ListOpType,
     macroname: Value,
     list: Expression,
-) -> ParseResult<Expression> {
+) -> ParseResult<'a, Expression> {
     if let Value::Selector(mut def) = macroname {
         // First of all we need to assert that this is a selector of at least
         // two sections.
@@ -701,7 +731,7 @@ fn tuple_to_list_op(
                 }
                 return Err(Error::new(
                     format!("Missing a result field for the macro"),
-                    &def.pos.offset,
+                    Box::new(input.clone()),
                 ));
             }
             &mut Some(ref mut tl) => {
@@ -714,7 +744,7 @@ fn tuple_to_list_op(
                     }
                     return Err(Error::new(
                         format!("Missing a result field for the macro"),
-                        &def.pos.offset,
+                        Box::new(input.clone()),
                     ));
                 }
                 let fname = tl.pop();
@@ -726,7 +756,7 @@ fn tuple_to_list_op(
             mac: def,
             field: fieldname,
             target: Box::new(list),
-            pos: pos,
+            pos: input.into(),
         }));
     }
     if ENABLE_TRACE {
@@ -737,21 +767,21 @@ fn tuple_to_list_op(
     }
     return Err(Error::new(
         format!("Expected a selector but got {}", macroname.type_name()),
-        &pos.offset,
+        Box::new(input.clone()),
     ));
 }
 
 make_fn!(
     list_op_expression<SliceIter<Token>, Expression>,
     do_each!(
-        pos => pos,
+        input => input!(),
         optype => either!(
             do_each!(_ => word!("map"), (ListOpType::Map)),
             do_each!(_ => word!("filter"), (ListOpType::Filter))
         ),
         macroname => trace_nom!(selector_value),
         list => trace_nom!(non_op_expression),
-        (tuple_to_list_op(pos, optype, macroname, list).unwrap())
+        (tuple_to_list_op(&input, optype, macroname, list).unwrap())
     )
 );
 
@@ -893,7 +923,7 @@ fn statement(i: SliceIter<Token>) -> Result<SliceIter<Token>, Statement> {
 
 /// Parses a LocatedSpan into a list of Statements or an `error::Error`.
 pub fn parse(input: OffsetStrIter) -> std::result::Result<Vec<Statement>, error::Error> {
-    match tokenize(input.clone()) {
+    match tokenize(&input) {
         Ok(tokenized) => {
             let mut out = Vec::new();
             let mut i_ = SliceIter::from(&tokenized);
@@ -907,20 +937,18 @@ pub fn parse(input: OffsetStrIter) -> std::result::Result<Vec<Statement>, error:
                 match statement(i.clone()) {
                     Result::Abort(e) => {
                         let pos: Position = (&i).into();
-                        let err = error::Error::new_with_boxed_cause(
-                            "Statement Parse Error",
+                        let err = error::Error::new(
+                            format!("Statement Parse Error {}", e),
                             error::ErrorType::ParseError,
-                            Box::new(e),
                             pos,
                         );
                         return Err(err);
                     }
                     Result::Fail(e) => {
                         let pos: Position = (&i).into();
-                        let err = error::Error::new_with_boxed_cause(
-                            "Statement Parse Error",
+                        let err = error::Error::new(
+                            format!("Statement Parse Error {}", e),
                             error::ErrorType::ParseError,
-                            Box::new(e),
                             pos,
                         );
                         return Err(err);

src/parse/precedence.rs

@@ -49,7 +49,10 @@ make_fn!(
 fn parse_expression(i: SliceIter<Element>) -> Result<SliceIter<Element>, Expression> {
     let mut i_ = i.clone();
     if eoi(i_.clone()).is_complete() {
-        return Result::Abort(Error::new("Expected Expression found End Of Input", &i_));
+        return Result::Abort(Error::new(
+            "Expected Expression found End Of Input",
+            Box::new(i_),
+        ));
     }
     let el = i_.next();
     if let Some(&Element::Expr(ref expr)) = el {
@@ -60,7 +63,7 @@ fn parse_expression(i: SliceIter<Element>) -> Result<SliceIter<Element>, Express
             "Error while parsing Binary Expression Expected Expression got {:?}",
             el
         ),
-        &i_,
+        Box::new(i_),
     ));
 }
 
@@ -69,7 +72,7 @@ fn parse_sum_operator(i: SliceIter<Element>) -> Result<SliceIter<Element>, Binar
     if eoi(i_.clone()).is_complete() {
         return Result::Fail(Error::new(
             format!("Expected Expression found End Of Input"),
-            &i_,
+            Box::new(i_),
         ));
     }
     let el = i_.next();
@@ -91,7 +94,7 @@ fn parse_sum_operator(i: SliceIter<Element>) -> Result<SliceIter<Element>, Binar
             "Error while parsing Binary Expression Unexpected Operator {:?}",
             el
         ),
-        &i_,
+        Box::new(i_),
     ));
 }
 
@@ -114,7 +117,7 @@ fn parse_product_operator(i: SliceIter<Element>) -> Result<SliceIter<Element>, B
     if eoi(i_.clone()).is_complete() {
         return Result::Fail(Error::new(
             format!("Expected Expression found End Of Input"),
-            &i_,
+            Box::new(i_),
         ));
     }
     let el = i_.next();
@@ -136,7 +139,7 @@ fn parse_product_operator(i: SliceIter<Element>) -> Result<SliceIter<Element>, B
             "Error while parsing Binary Expression Unexpected Operator {:?}",
             el
         ),
-        &i_,
+        Box::new(i_),
     ));
 }
 
@@ -224,7 +227,7 @@ fn parse_compare_operator(i: SliceIter<Element>) -> Result<SliceIter<Element>, C
     if eoi(i_.clone()).is_complete() {
         return Result::Fail(Error::new(
             format!("Expected Expression found End Of Input"),
-            &i_,
+            Box::new(i_),
         ));
     }
     let el = i_.next();
@@ -236,7 +239,7 @@ fn parse_compare_operator(i: SliceIter<Element>) -> Result<SliceIter<Element>, C
             "Error while parsing Binary Expression Unexpected Operator {:?}",
             el
         ),
-        &i,
+        Box::new(i),
     ));
 }
 
@@ -309,24 +312,51 @@ fn parse_operand_list<'a>(i: SliceIter<'a, Token>) -> NomResult<'a, Vec<Element>
 }
 
 /// Parse a binary operator expression.
-pub fn op_expression<'a>(i: SliceIter<'a, Token>) -> NomResult<'a, Expression> {
+pub fn op_expression<'a>(i: SliceIter<'a, Token>) -> Result<SliceIter<Token>, Expression> {
     let preparse = parse_operand_list(i.clone());
     match preparse {
-        Result::Fail(e) => Result::Fail(e),
-        Result::Abort(e) => Result::Abort(e),
+        Result::Fail(e) => {
+            let err = Error::caused_by(
+                "Failed while parsing operator expression",
+                Box::new(e),
+                Box::new(i),
+            );
+            Result::Fail(err)
+        }
+        Result::Abort(e) => {
+            let err = Error::caused_by(
+                "Failed while parsing operator expression",
+                Box::new(e),
+                Box::new(i),
+            );
+            Result::Fail(err)
+        }
         Result::Incomplete(i) => Result::Incomplete(i),
         Result::Complete(rest, oplist) => {
             let mut i_ = SliceIter::new(&oplist);
             let parse_result = either!(
-                i_,
+                i_.clone(),
                 trace_nom!(compare_expression),
                 trace_nom!(math_expression)
             );
 
             match parse_result {
-                Result::Fail(e) => Result::Fail(e),
-                Result::Abort(e) => Result::Abort(e),
-                Result::Incomplete(i) => Result::Incomplete(i),
+                Result::Fail(_e) => {
+                    // TODO(jwall): It would be good to be able to use caused_by here.
+                    let err = Error::new(
+                        "Failed while parsing operator expression",
+                        Box::new(rest.clone()),
+                    );
+                    Result::Fail(err)
+                }
+                Result::Abort(_e) => {
+                    let err = Error::new(
+                        "Failed while parsing operator expression",
+                        Box::new(rest.clone()),
+                    );
+                    Result::Abort(err)
+                }
+                Result::Incomplete(_) => Result::Incomplete(i.clone()),
                 Result::Complete(_, expr) => Result::Complete(rest.clone(), expr),
             }
         }

src/parse/test.rs

@@ -24,7 +24,7 @@ macro_rules! assert_parse {
     };
     ($i:expr, $f:expr, $out:expr) => {{
         let input = OffsetStrIter::new($i);
-        match tokenize(input) {
+        match tokenize(&input) {
             Err(e) => assert!(false, format!("Tokenizer Error: {:?}", e)),
             Ok(val) => match $f(SliceIter::new(val.as_slice())) {
                 Result::Complete(_, result) => assert_eq!(result, $out),
@@ -40,7 +40,7 @@ macro_rules! assert_fail {
     };
     ($i:expr, $f:expr) => {{
         let input = OffsetStrIter::new($i);
-        match tokenize(input) {
+        match tokenize(&input) {
             Err(_) => assert!(true),
             Ok(val) => {
                 let result = $f(SliceIter::new(val.as_slice()));
@@ -56,7 +56,7 @@ macro_rules! assert_abort {
     };
     ($i:expr, $f:expr) => {{
         let input = OffsetStrIter::new($i);
-        match tokenize(input) {
+        match tokenize(&input) {
             Err(_) => assert!(true),
             Ok(val) => {
                 let result = $f(SliceIter::new(val.as_slice()));

src/tokenizer/mod.rs

@@ -27,12 +27,20 @@ fn is_symbol_char<'a>(i: OffsetStrIter<'a>) -> Result<OffsetStrIter<'a>, u8> {
     let mut _i = i.clone();
     let c = match _i.next() {
         Some(c) => *c,
-        None => return Result::Fail(Error::new("Unexpected End of Input".to_string(), &_i)),
+        None => {
+            return Result::Fail(Error::new(
+                "Unexpected End of Input".to_string(),
+                Box::new(_i.clone()),
+            ))
+        }
     };
     if (c as char).is_ascii_alphanumeric() || c == b'-' || c == b'_' {
         Result::Complete(_i, c)
     } else {
-        Result::Fail(Error::new("Not a symbol character".to_string(), &_i))
+        Result::Fail(Error::new(
+            "Not a symbol character".to_string(),
+            Box::new(_i.clone()),
+        ))
     }
 }
 
@@ -60,7 +68,7 @@ fn escapequoted<'a>(input: OffsetStrIter<'a>) -> Result<OffsetStrIter<'a>, Strin
             escape = false; // reset our escaping sentinel
         }
     }
-    return Result::Incomplete(_input.get_offset());
+    return Result::Incomplete(_input.clone());
 }
 
 make_fn!(strtok<OffsetStrIter, Token>,
@@ -304,11 +312,14 @@ fn comment(input: OffsetStrIter) -> Result<OffsetStrIter, Token> {
                 }
                 // If we didn't find a new line then we just grab everything.
                 _ => {
-                    return Result::Abort(Error::new("Unparsable comment".to_string(), &rest));
+                    return Result::Abort(Error::new(
+                        "Unparsable comment".to_string(),
+                        Box::new(rest.clone()),
+                    ));
                 }
             }
         }
-        Result::Incomplete(offset) => return Result::Incomplete(offset),
+        Result::Incomplete(ctx) => return Result::Incomplete(ctx),
         Result::Fail(e) => return Result::Fail(e),
         Result::Abort(e) => return Result::Abort(e),
     }
@@ -339,8 +350,9 @@ make_fn!(end_of_input<OffsetStrIter, Token>,
     )
 );
 
-make_fn!(token<OffsetStrIter, Token>,
+fn token<'a>(input: OffsetStrIter<'a>) -> Result<OffsetStrIter<'a>, Token> {
     either!(
+        input,
         strtok,
         pipequotetok,
         emptytok, // This must come before the barewordtok
@@ -380,11 +392,12 @@ make_fn!(token<OffsetStrIter, Token>,
         filtertok,
         barewordtok,
         whitespace,
-        end_of_input)
-);
+        end_of_input
+    )
+}
 
 /// Consumes an input OffsetStrIter and returns either a Vec<Token> or a error::Error.
-pub fn tokenize(input: OffsetStrIter) -> std::result::Result<Vec<Token>, error::Error> {
+pub fn tokenize(input: &OffsetStrIter) -> std::result::Result<Vec<Token>, error::Error> {
     let mut out = Vec::new();
     let mut i = input.clone();
     loop {
@@ -392,27 +405,24 @@ pub fn tokenize(input: OffsetStrIter) -> std::result::Result<Vec<Token>, error::
             break;
         }
         let pos: Position = Position::from(&i);
-        // FIXME(jwall): We need to return a error::Error so we have position information.
         match token(i.clone()) {
             Result::Abort(e) => {
-                return Err(error::Error::new_with_boxed_cause(
-                    "Invalid Token encountered",
+                return Err(error::Error::new(
+                    format!("Invalid Token encountered {}", e),
                     error::ErrorType::UnexpectedToken,
-                    Box::new(e),
                     pos,
                 ))
             }
             Result::Fail(e) => {
-                return Err(error::Error::new_with_boxed_cause(
-                    "Invalid Token encountered",
+                return Err(error::Error::new(
+                    format!("Invalid Token encountered {}", e),
                     error::ErrorType::UnexpectedToken,
-                    Box::new(e),
                     pos,
                 ))
             }
             Result::Incomplete(_offset) => {
                 return Err(error::Error::new(
-                    "Invalid Token encountered",
+                    "Incomplete Token encountered",
                     error::ErrorType::IncompleteParsing,
                     pos,
                 ))
@@ -439,7 +449,7 @@ pub fn tokenize(input: OffsetStrIter) -> std::result::Result<Vec<Token>, error::
 /// Clones a token.
 ///
 /// This is necessary to allow the match_type and match_token macros to work.
-pub fn token_clone(t: &Token) -> std::result::Result<Token, Error> {
+pub fn token_clone(t: &Token) -> std::result::Result<Token, Error<SliceIter<Token>>> {
     Ok(t.clone())
 }
 
@@ -517,7 +527,7 @@ macro_rules! match_type {
 
         let mut _i = $i.clone();
         if eoi(_i.clone()).is_complete() {
-            Result::Fail(Error::new(format!("End of Input! {}", $msg), &$i))
+            Result::Fail(Error::new(format!("End of Input! {}", $msg), Box::new(_i)))
         } else {
             match _i.next() {
                 Some(tok) => {
@@ -525,14 +535,14 @@ macro_rules! match_type {
                         match $h(tok) {
                             std::result::Result::Ok(v) => Result::Complete(_i.clone(), v),
                             std::result::Result::Err(e) => {
-                                Result::Fail(Error::caused_by($msg, &_i, Box::new(e)))
+                                Result::Fail(Error::caused_by($msg, Box::new(e), Box::new(_i)))
                             }
                         }
                     } else {
-                        Result::Fail(Error::new($msg.to_string(), &$i))
+                        Result::Fail(Error::new($msg.to_string(), Box::new($i)))
                     }
                 }
-                None => Result::Fail(Error::new($msg.to_string(), &$i)),
+                None => Result::Fail(Error::new($msg.to_string(), Box::new($i))),
             }
         }
     }};
@@ -575,17 +585,17 @@ macro_rules! match_token {
                 match $h(tok) {
                     std::result::Result::Ok(v) => Result::Complete(i_.clone(), v),
                     std::result::Result::Err(e) => {
-                        Result::Fail(Error::caused_by($msg, &i_, Box::new(e)))
+                        Result::Fail(Error::caused_by($msg, Box::new(e), Box::new(i_)))
                     }
                 }
             } else {
                 Result::Fail(Error::new(
                     format!("Expected {} Instead is ({})", $msg, tok.fragment),
-                    &i_,
+                    Box::new(i_),
                 ))
             }
         } else {
-            Result::Fail(Error::new("Unexpected End Of Input", &i_))
+            Result::Fail(Error::new("Unexpected End Of Input", Box::new(i_)))
         }
     }};
 }

src/tokenizer/test.rs

@@ -101,7 +101,8 @@ fn test_string_with_escaping() {
 
 #[test]
 fn test_tokenize_bareword_with_dash() {
-    let result = tokenize(OffsetStrIter::new("foo-bar "));
+    let input = OffsetStrIter::new("foo-bar ");
+    let result = tokenize(&input);
     assert!(result.is_ok(), format!("result {:?} is not ok", result));
     if let Ok(toks) = result {
         assert_eq!(toks.len(), 2);
@@ -165,10 +166,11 @@ fn test_lteqtok() {
 
 #[test]
 fn test_tokenize_one_of_each() {
-    let result = tokenize(OffsetStrIter::new(
+    let input = OffsetStrIter::new(
         "map out filter assert let import macro select as => [ ] { } ; = % / * \
          + - . ( ) , 1 . foo \"bar\" // comment\n ; true false == < > <= >= !=",
-    ));
+    );
+    let result = tokenize(&input);
     assert!(result.is_ok(), format!("result {:?} is not ok", result));
     let v = result.unwrap();
     for (i, t) in v.iter().enumerate() {
@@ -180,7 +182,8 @@ fn test_tokenize_one_of_each() {
 
 #[test]
 fn test_parse_has_end() {
-    let result = tokenize(OffsetStrIter::new("foo"));
+    let input = OffsetStrIter::new("foo");
+    let result = tokenize(&input);
     assert!(result.is_ok());
     let v = result.unwrap();
     assert_eq!(v.len(), 2);