diff --git a/src/ast.rs b/src/ast.rs
index b29755a6..96899b0e 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -1,4 +1,4 @@
-use pest::iterators::{Pair, Pairs};
+use pest::iterators::{Pair};
 use pest::Parser as PestParser;
 use pest::prec_climber::{Assoc, PrecClimber, Operator};
 use crate::parser::Parser;
@@ -6,7 +6,7 @@ use crate::parser::Rule;
 use lazy_static::lazy_static;
 use crate::ast::Expr::{Apply, Const};
 use crate::error::CozoError;
-use crate::error::CozoError::ReservedIdent;
+use crate::error::Result;
 use crate::value::Value;
 
 
@@ -66,7 +66,7 @@ pub trait ExprVisitor<'a, T> {
 }
 
 
-fn build_expr_infix<'a>(lhs: Result<Expr<'a>, CozoError>, op: Pair<Rule>, rhs: Result<Expr<'a>, CozoError>) -> Result<Expr<'a>, CozoError> {
+fn build_expr_infix<'a>(lhs: Result<Expr<'a>>, op: Pair<Rule>, rhs: Result<Expr<'a>>) -> Result<Expr<'a>> {
     let lhs = lhs?;
     let rhs = rhs?;
     let op = match op.as_rule() {
@@ -96,12 +96,12 @@ fn parse_int(s: &str, radix: u32) -> i64 {
 }
 
 #[inline]
-fn parse_raw_string(pair: Pair<Rule>) -> Result<String, CozoError> {
+fn parse_raw_string(pair: Pair<Rule>) -> Result<String> {
     Ok(pair.into_inner().into_iter().next().unwrap().as_str().to_string())
 }
 
 #[inline]
-fn parse_quoted_string(pair: Pair<Rule>) -> Result<String, CozoError> {
+fn parse_quoted_string(pair: Pair<Rule>) -> Result<String> {
     let pairs = pair.into_inner().next().unwrap().into_inner();
     let mut ret = String::with_capacity(pairs.as_str().len());
     for pair in pairs {
@@ -129,7 +129,7 @@ fn parse_quoted_string(pair: Pair<Rule>) -> Result<String, CozoError> {
 
 
 #[inline]
-fn parse_s_quoted_string(pair: Pair<Rule>) -> Result<String, CozoError> {
+fn parse_s_quoted_string(pair: Pair<Rule>) -> Result<String> {
     let pairs = pair.into_inner().next().unwrap().into_inner();
     let mut ret = String::with_capacity(pairs.as_str().len());
     for pair in pairs {
@@ -156,7 +156,7 @@ fn parse_s_quoted_string(pair: Pair<Rule>) -> Result<String, CozoError> {
 }
 
 #[inline]
-pub fn parse_string(pair: Pair<Rule>) -> Result<String, CozoError>  {
+pub fn parse_string(pair: Pair<Rule>) -> Result<String>  {
     match pair.as_rule() {
         Rule::quoted_string => Ok(parse_quoted_string(pair)?),
         Rule::s_quoted_string => Ok(parse_s_quoted_string(pair)?),
@@ -165,7 +165,7 @@ pub fn parse_string(pair: Pair<Rule>) -> Result<String, CozoError>  {
     }
 }
 
-fn build_expr_primary(pair: Pair<Rule>) -> Result<Expr, CozoError> {
+fn build_expr_primary(pair: Pair<Rule>) -> Result<Expr> {
     match pair.as_rule() {
         Rule::expr => build_expr_primary(pair.into_inner().next().unwrap()),
         Rule::term => build_expr_primary(pair.into_inner().next().unwrap()),
@@ -189,7 +189,7 @@ fn build_expr_primary(pair: Pair<Rule>) -> Result<Expr, CozoError> {
         Rule::dot_float | Rule::sci_float => Ok(Const(Value::Float(pair.as_str().replace('_', "").parse::<f64>()?))),
         Rule::null => Ok(Const(Value::Null)),
         Rule::boolean => Ok(Const(Value::Bool(pair.as_str() == "true"))),
-        Rule::quoted_string | Rule::s_quoted_string | Rule::s_quoted_string => Ok(
+        Rule::quoted_string | Rule::s_quoted_string | Rule::raw_string => Ok(
             Const(Value::OwnString(Box::new(parse_string(pair)?)))),
         _ => {
             println!("{:#?}", pair);
@@ -198,11 +198,11 @@ fn build_expr_primary(pair: Pair<Rule>) -> Result<Expr, CozoError> {
     }
 }
 
-fn build_expr(pair: Pair<Rule>) -> Result<Expr, CozoError> {
+fn build_expr(pair: Pair<Rule>) -> Result<Expr> {
     PREC_CLIMBER.climb(pair.into_inner(), build_expr_primary, build_expr_infix)
 }
 
-pub fn parse_expr_from_str(inp: &str) -> Result<Expr, CozoError> {
+pub fn parse_expr_from_str(inp: &str) -> Result<Expr> {
     let expr_tree = Parser::parse(Rule::expr, inp)?.next().unwrap();
     build_expr(expr_tree)
 }
diff --git a/src/definition.rs b/src/definition.rs
index d140526f..424467b6 100644
--- a/src/definition.rs
+++ b/src/definition.rs
@@ -1,11 +1,10 @@
-use pest::Parser as PestParser;
 use pest::iterators::{Pair, Pairs};
 use crate::ast::parse_string;
 use crate::env::Env;
-use crate::error::CozoError;
+use crate::error::Result;
 use crate::error::CozoError::*;
-use crate::parser::{Parser, Rule};
-use crate::typing::{BaseType, Col, Edge, Node, Structured, StructuredEnv, StructuredEnvItem, TableId, Typing};
+use crate::parser::{Rule};
+use crate::typing::{Col, Edge, Node, Structured, StructuredEnv, StructuredEnvItem, TableId, Typing};
 use crate::typing::Persistence::{Global, Local};
 use crate::typing::StorageStatus::Planned;
 use crate::value::Value;
@@ -14,7 +13,7 @@ fn parse_ident(pair: Pair<Rule>) -> String {
     pair.as_str().to_string()
 }
 
-fn build_name_in_def(pair: Pair<Rule>, forbid_underscore: bool) -> Result<String, CozoError> {
+fn build_name_in_def(pair: Pair<Rule>, forbid_underscore: bool) -> Result<String> {
     let inner = pair.into_inner().next().unwrap();
     let name = match inner.as_rule() {
         Rule::ident => parse_ident(inner),
@@ -28,7 +27,7 @@ fn build_name_in_def(pair: Pair<Rule>, forbid_underscore: bool) -> Result<String
     }
 }
 
-fn parse_col_name(pair: Pair<Rule>) -> Result<(String, bool), CozoError> {
+fn parse_col_name(pair: Pair<Rule>) -> Result<(String, bool)> {
     let mut pairs = pair.into_inner();
     let mut is_key = false;
     let mut nxt_pair = pairs.next().unwrap();
@@ -42,7 +41,7 @@ fn parse_col_name(pair: Pair<Rule>) -> Result<(String, bool), CozoError> {
 
 
 impl StructuredEnvItem {
-    pub fn build_edge_def(&mut self, pair: Pair<Rule>, table_id: TableId) -> Result<(), CozoError> {
+    pub fn build_edge_def(&mut self, pair: Pair<Rule>, table_id: TableId) -> Result<()> {
         let mut inner = pair.into_inner();
         let src_name = build_name_in_def(inner.next().unwrap(), true)?;
         let src = self.resolve(&src_name).ok_or(UndefinedType)?;
@@ -91,7 +90,7 @@ impl StructuredEnvItem {
             Err(NameConflict)
         }
     }
-    pub fn build_node_def(&mut self, pair: Pair<Rule>, table_id: TableId) -> Result<(), CozoError> {
+    pub fn build_node_def(&mut self, pair: Pair<Rule>, table_id: TableId) -> Result<()> {
         let mut inner = pair.into_inner();
         let name = build_name_in_def(inner.next().unwrap(), true)?;
         let (keys, cols) = self.build_col_defs(inner.next().unwrap())?;
@@ -110,7 +109,7 @@ impl StructuredEnvItem {
         }
     }
 
-    fn build_type(&self, pair: Pair<Rule>) -> Result<Typing, CozoError> {
+    fn build_type(&self, pair: Pair<Rule>) -> Result<Typing> {
         let mut pairs = pair.into_inner();
         let mut inner = pairs.next().unwrap();
         let nullable = if Rule::nullable_marker == inner.as_rule() {
@@ -142,12 +141,12 @@ impl StructuredEnvItem {
         })
     }
 
-    fn build_default_value(&self, _pair: Pair<Rule>) -> Result<Value<'static>, CozoError> {
+    fn build_default_value(&self, _pair: Pair<Rule>) -> Result<Value<'static>> {
         // TODO: _pair is an expression, parse it and evaluate it to a constant value
         Ok(Value::Null)
     }
 
-    fn build_col_entry(&self, pair: Pair<Rule>) -> Result<(Col, bool), CozoError> {
+    fn build_col_entry(&self, pair: Pair<Rule>) -> Result<(Col, bool)> {
         let mut pairs = pair.into_inner();
         let (name, is_key) = parse_col_name(pairs.next().unwrap())?;
         let typ = self.build_type(pairs.next().unwrap())?;
@@ -164,7 +163,7 @@ impl StructuredEnvItem {
         }, is_key))
     }
 
-    fn build_col_defs(&self, pair: Pair<Rule>) -> Result<(Vec<Col>, Vec<Col>), CozoError> {
+    fn build_col_defs(&self, pair: Pair<Rule>) -> Result<(Vec<Col>, Vec<Col>)> {
         let mut keys = vec![];
         let mut cols = vec![];
         for pair in pair.into_inner() {
@@ -181,7 +180,7 @@ impl StructuredEnvItem {
 }
 
 impl StructuredEnv {
-    pub fn build_table(&mut self, pairs: Pairs<Rule>) -> Result<(), CozoError> {
+    pub fn build_table(&mut self, pairs: Pairs<Rule>) -> Result<()> {
         for pair in pairs {
             match pair.as_rule() {
                 r @ (Rule::global_def | Rule::local_def) => {
@@ -217,6 +216,8 @@ impl StructuredEnv {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use pest::Parser as PestParser;
+    use crate::parser::Parser;
 
     #[test]
     fn definitions() {
diff --git a/src/error.rs b/src/error.rs
index 6bef80ee..589db792 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -1,3 +1,4 @@
+use std::result;
 use thiserror::Error;
 use crate::parser::Rule;
 
@@ -36,3 +37,5 @@ pub enum CozoError {
     #[error(transparent)]
     Parse(#[from] pest::error::Error<Rule>),
 }
+
+pub type Result<T> = result::Result<T, CozoError>;
\ No newline at end of file
diff --git a/src/eval.rs b/src/eval.rs
index 0816ad2d..64cf4026 100644
--- a/src/eval.rs
+++ b/src/eval.rs
@@ -1,5 +1,6 @@
 use crate::ast::Expr;
 use crate::ast::Expr::*;
+use crate::error::Result;
 use crate::error::CozoError;
 use crate::error::CozoError::*;
 use crate::value::Value::*;
@@ -22,8 +23,8 @@ impl Default for Evaluator {
     }
 }
 
-impl<'a> ExprVisitor<'a, Result<Expr<'a>, CozoError>> for Evaluator {
-    fn visit_expr(&mut self, ex: &Expr<'a>) -> Result<Expr<'a>, CozoError> {
+impl<'a> ExprVisitor<'a, Result<Expr<'a>>> for Evaluator {
+    fn visit_expr(&mut self, ex: &Expr<'a>) -> Result<Expr<'a>> {
         match ex {
             Apply(op, args) => {
                 match op {
@@ -55,7 +56,7 @@ impl<'a> ExprVisitor<'a, Result<Expr<'a>, CozoError>> for Evaluator {
 }
 
 impl Evaluator {
-    fn add_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn add_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -84,7 +85,7 @@ impl Evaluator {
         }
     }
 
-    fn sub_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn sub_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -109,7 +110,7 @@ impl Evaluator {
         }
     }
 
-    fn mul_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn mul_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -135,7 +136,7 @@ impl Evaluator {
     }
 
 
-    fn div_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn div_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -160,7 +161,7 @@ impl Evaluator {
         }
     }
 
-    fn mod_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn mod_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -183,7 +184,7 @@ impl Evaluator {
     }
 
 
-    fn eq_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn eq_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -201,7 +202,7 @@ impl Evaluator {
     }
 
 
-    fn ne_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn ne_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -219,7 +220,7 @@ impl Evaluator {
     }
 
 
-    fn gt_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn gt_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -245,7 +246,7 @@ impl Evaluator {
     }
 
 
-    fn ge_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn ge_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -271,7 +272,7 @@ impl Evaluator {
     }
 
 
-    fn lt_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn lt_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -296,7 +297,7 @@ impl Evaluator {
         }
     }
 
-    fn le_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn le_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -322,7 +323,7 @@ impl Evaluator {
     }
 
 
-    fn pow_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn pow_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -347,7 +348,7 @@ impl Evaluator {
         }
     }
 
-    fn coalesce_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn coalesce_exprs<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         match exprs {
             [a, b] => {
                 let a = self.visit_expr(a)?;
@@ -367,7 +368,7 @@ impl Evaluator {
         }
     }
 
-    fn negate_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn negate_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         Ok(match exprs {
             [a] => {
                 match self.visit_expr(a)? {
@@ -391,7 +392,7 @@ impl Evaluator {
     }
 
 
-    fn minus_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn minus_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         Ok(match exprs {
             [a] => {
                 match self.visit_expr(a)? {
@@ -408,7 +409,7 @@ impl Evaluator {
     }
 
 
-    fn test_null_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn test_null_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         Ok(match exprs {
             [a] => {
                 match self.visit_expr(a)? {
@@ -421,7 +422,7 @@ impl Evaluator {
         })
     }
 
-    fn not_null_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn not_null_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         Ok(match exprs {
             [a] => {
                 match self.visit_expr(a)? {
@@ -434,7 +435,7 @@ impl Evaluator {
         })
     }
 
-    fn or_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn or_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         let mut unevaluated = vec![];
         let mut has_null = false;
         for expr in exprs {
@@ -467,7 +468,7 @@ impl Evaluator {
     }
 
 
-    fn and_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>, CozoError> {
+    fn and_expr<'a>(&mut self, exprs: &[Expr<'a>]) -> Result<Expr<'a>> {
         let mut unevaluated = vec![];
         let mut no_null = true;
         for expr in exprs {
diff --git a/src/parser.rs b/src/parser.rs
index d8352e92..a63c7962 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1,4 +1,3 @@
-use pest::Parser as PestParser;
 use pest_derive::Parser;
 
 
@@ -10,6 +9,7 @@ pub struct Parser;
 #[cfg(test)]
 mod tests {
     use super::*;
+    use pest::Parser as PestParser;
 
     #[test]
     fn db() {
@@ -66,9 +66,7 @@ mod tests {
     #[test]
     fn numbers() {
         assert_eq!(Parser::parse(Rule::number, "123").unwrap().as_str(), "123");
-        assert_eq!(Parser::parse(Rule::number, "-123").unwrap().as_str(), "-123");
         assert_eq!(Parser::parse(Rule::number, "0").unwrap().as_str(), "0");
-        assert_eq!(Parser::parse(Rule::number, "-0").unwrap().as_str(), "-0");
         assert_eq!(Parser::parse(Rule::number, "0123").unwrap().as_str(), "0123");
         assert_eq!(Parser::parse(Rule::number, "000_1").unwrap().as_str(), "000_1");
         assert!(Parser::parse(Rule::number, "_000_1").is_err());
@@ -81,7 +79,6 @@ mod tests {
         assert_eq!(Parser::parse(Rule::number, "123.45").unwrap().as_str(), "123.45");
         assert_eq!(Parser::parse(Rule::number, "1_23.4_5_").unwrap().as_str(), "1_23.4_5_");
         assert_ne!(Parser::parse(Rule::number, "123.").unwrap().as_str(), "123.");
-        assert_eq!(Parser::parse(Rule::number, "-123e-456").unwrap().as_str(), "-123e-456");
         assert_eq!(Parser::parse(Rule::number, "123.333e456").unwrap().as_str(), "123.333e456");
         assert_eq!(Parser::parse(Rule::number, "1_23.33_3e45_6").unwrap().as_str(), "1_23.33_3e45_6");
     }
diff --git a/src/typing.rs b/src/typing.rs
index 38c7a7fd..7308d92b 100644
--- a/src/typing.rs
+++ b/src/typing.rs
@@ -1,5 +1,4 @@
 use std::collections::BTreeMap;
-use crate::ast::Op;
 use crate::env::{Env, LayeredEnv};
 use crate::value::Value;