diff --git a/src/ast/mod.rs b/src/ast/mod.rs
index e90fe34..a713832 100644
--- a/src/ast/mod.rs
+++ b/src/ast/mod.rs
@@ -55,6 +55,7 @@ macro_rules! enum_type_equality {
 /// parts of the UCG AST have a positioned associated with them.
 #[derive(Debug, PartialEq, Eq, Clone, PartialOrd, Ord, Hash)]
 pub struct Position {
+    pub file: Option<PathBuf>,
     pub line: usize,
     pub column: usize,
     pub offset: usize,
@@ -64,6 +65,7 @@ impl Position {
     /// Construct a new Position.
     pub fn new(line: usize, column: usize, offset: usize) -> Self {
         Position {
+            file: None,
             line: line,
             column: column,
             offset: offset,
@@ -373,8 +375,6 @@ impl<'a> From<&'a PositionedItem<String>> for PositionedItem<String> {
 /// Encodes a macro expression in the UCG AST..
 ///
 /// A macro is a pure function over a tuple.
-/// MacroDefs are not closures. They can not reference
-/// any values except what is defined in their arguments.
 #[derive(PartialEq, Debug, Clone)]
 pub struct MacroDef {
     pub scope: Option<Scope>,
diff --git a/src/iter.rs b/src/iter.rs
index 99664ac..9936735 100644
--- a/src/iter.rs
+++ b/src/iter.rs
@@ -1,6 +1,7 @@
 //! Input stream wrappers for use in abortable_parser.
 use std::convert::From;
 use std::iter::Iterator;
+use std::path::PathBuf;
 
 use abortable_parser::iter::{SliceIter, StrIter};
 use abortable_parser::{InputIter, Offsetable, Peekable, Positioned, Seekable, Span, SpanRange};
@@ -9,6 +10,7 @@ use crate::ast::{Position, Token};
 
 #[derive(Debug)]
 pub struct OffsetStrIter<'a> {
+    source_file: Option<PathBuf>,
     contained: StrIter<'a>,
     line_offset: usize,
     col_offset: usize,
@@ -21,11 +23,17 @@ impl<'a> OffsetStrIter<'a> {
 
     pub fn new_with_offsets(input: &'a str, line_offset: usize, col_offset: usize) -> Self {
         OffsetStrIter {
+            source_file: None,
             contained: StrIter::new(input),
             line_offset: line_offset,
             col_offset: col_offset,
         }
     }
+
+    pub fn with_src_file(mut self, file: PathBuf) -> Self {
+        self.source_file = Some(file);
+        self
+    }
 }
 
 impl<'a> Iterator for OffsetStrIter<'a> {
@@ -45,6 +53,7 @@ impl<'a> Offsetable for OffsetStrIter<'a> {
 impl<'a> Clone for OffsetStrIter<'a> {
     fn clone(&self) -> Self {
         OffsetStrIter {
+            source_file: self.source_file.clone(),
             contained: self.contained.clone(),
             line_offset: self.line_offset,
             col_offset: self.col_offset,
@@ -55,6 +64,7 @@ impl<'a> Clone for OffsetStrIter<'a> {
 impl<'a> From<&'a str> for OffsetStrIter<'a> {
     fn from(source: &'a str) -> Self {
         OffsetStrIter {
+            source_file: None,
             contained: StrIter::new(source),
             line_offset: 0,
             col_offset: 0,
@@ -103,6 +113,11 @@ impl<'a> From<&'a SliceIter<'a, Token>> for Position {
 
 impl<'a> From<&'a OffsetStrIter<'a>> for Position {
     fn from(s: &'a OffsetStrIter<'a>) -> Position {
-        Position::new(s.line(), s.column(), s.get_offset())
+        Position {
+            file: s.source_file.clone(),
+            line: s.line(),
+            column: s.column(),
+            offset: s.get_offset(),
+        }
     }
 }
diff --git a/src/main.rs b/src/main.rs
index cffa276..63d3e74 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -266,6 +266,7 @@ fn inspect_command(
                     } else {
                         sym_name.to_owned()
                     };
+                    let mut builder = builder.clone_builder("/eval");
                     match builder.eval_string(&normalized) {
                         Ok(v) => Some(v.clone()),
                         Err(e) => {
diff --git a/src/tokenizer/test.rs b/src/tokenizer/test.rs
index 66a6eff..c05afc2 100644
--- a/src/tokenizer/test.rs
+++ b/src/tokenizer/test.rs
@@ -203,6 +203,7 @@ fn test_parse_comment() {
                 typ: TokenType::COMMENT,
                 fragment: " comment".to_string(),
                 pos: Position {
+                    file: None,
                     line: 1,
                     column: 1,
                     offset: 0
@@ -219,6 +220,7 @@ fn test_parse_comment() {
                 typ: TokenType::COMMENT,
                 fragment: " comment".to_string(),
                 pos: Position {
+                    file: None,
                     column: 1,
                     line: 1,
                     offset: 0
@@ -235,6 +237,7 @@ fn test_parse_comment() {
                 typ: TokenType::COMMENT,
                 fragment: " comment".to_string(),
                 pos: Position {
+                    file: None,
                     column: 1,
                     line: 1,
                     offset: 0
@@ -251,6 +254,7 @@ fn test_match_word() {
         fragment: "foo".to_string(),
         typ: TokenType::BAREWORD,
         pos: Position {
+            file: None,
             line: 1,
             column: 1,
             offset: 0,
@@ -269,6 +273,7 @@ fn test_match_word_empty_input() {
         fragment: "".to_string(),
         typ: TokenType::END,
         pos: Position {
+            file: None,
             line: 1,
             column: 1,
             offset: 0,
@@ -291,6 +296,7 @@ fn test_match_punct() {
         fragment: "!".to_string(),
         typ: TokenType::PUNCT,
         pos: Position {
+            file: None,
             line: 1,
             column: 1,
             offset: 0,
@@ -309,6 +315,7 @@ fn test_match_type() {
         fragment: "foo".to_string(),
         typ: TokenType::BAREWORD,
         pos: Position {
+            file: None,
             line: 1,
             column: 1,
             offset: 0,