diff --git a/asg/src/statement/iteration.rs b/asg/src/statement/iteration.rs
index 756a8df33f..d5908d24da 100644
--- a/asg/src/statement/iteration.rs
+++ b/asg/src/statement/iteration.rs
@@ -57,6 +57,19 @@ impl<'a> FromAst<'a, leo_ast::IterationStatement> for &'a Statement<'a> {
         let expected_index_type = Some(PartialType::Integer(None, Some(IntegerType::U32)));
         let start = <&Expression<'a>>::from_ast(scope, &statement.start, expected_index_type.clone())?;
         let stop = <&Expression<'a>>::from_ast(scope, &statement.stop, expected_index_type)?;
+
+        // Return an error if start or stop is not constant.
+        if !start.is_consty() {
+            return Err(AsgConvertError::unexpected_nonconst(
+                &start.span().cloned().unwrap_or_default(),
+            ));
+        }
+        if !stop.is_consty() {
+            return Err(AsgConvertError::unexpected_nonconst(
+                &stop.span().cloned().unwrap_or_default(),
+            ));
+        }
+
         let variable = scope.context.alloc_variable(RefCell::new(InnerVariable {
             id: scope.context.get_id(),
             name: statement.variable.clone(),
diff --git a/ast/src/common/input_keyword.rs b/ast/src/common/input_keyword.rs
index cc9d167861..fecf89322e 100644
--- a/ast/src/common/input_keyword.rs
+++ b/ast/src/common/input_keyword.rs
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
 
-use crate::{Node, Span};
+use crate::{Identifier, Node, Span};
 
 use serde::{Deserialize, Serialize};
 use std::fmt;
@@ -22,8 +22,9 @@ use std::fmt;
 /// The `input` keyword can view program register, record, and state values.
 /// Values cannot be modified. The `input` keyword cannot be made mutable.
 #[derive(Clone, Serialize, Deserialize, Debug, PartialEq, Eq)]
+#[serde(transparent)]
 pub struct InputKeyword {
-    pub span: Span,
+    pub identifier: Identifier,
 }
 
 impl fmt::Display for InputKeyword {
@@ -34,10 +35,10 @@ impl fmt::Display for InputKeyword {
 
 impl Node for InputKeyword {
     fn span(&self) -> &Span {
-        &self.span
+        &self.identifier.span
     }
 
     fn set_span(&mut self, span: Span) {
-        self.span = span;
+        self.identifier.span = span;
     }
 }
diff --git a/ast/src/common/mut_self_keyword.rs b/ast/src/common/mut_self_keyword.rs
index 34de7c9921..d28c501be8 100644
--- a/ast/src/common/mut_self_keyword.rs
+++ b/ast/src/common/mut_self_keyword.rs
@@ -14,15 +14,16 @@
 // You should have received a copy of the GNU General Public License
 // along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
 
-use crate::{Node, Span};
+use crate::{Identifier, Node, Span};
 
 use serde::{Deserialize, Serialize};
 use std::fmt;
 
 /// The `mut self` keyword can view and modify circuit values inside of a circuit function.
 #[derive(Clone, Serialize, Deserialize, Debug, PartialEq, Eq)]
+#[serde(transparent)]
 pub struct MutSelfKeyword {
-    pub span: Span,
+    pub identifier: Identifier,
 }
 
 impl fmt::Display for MutSelfKeyword {
@@ -33,10 +34,10 @@ impl fmt::Display for MutSelfKeyword {
 
 impl Node for MutSelfKeyword {
     fn span(&self) -> &Span {
-        &self.span
+        &self.identifier.span
     }
 
     fn set_span(&mut self, span: Span) {
-        self.span = span;
+        self.identifier.span = span;
     }
 }
diff --git a/ast/src/common/self_keyword.rs b/ast/src/common/self_keyword.rs
index ba92db2160..06b6bb12a8 100644
--- a/ast/src/common/self_keyword.rs
+++ b/ast/src/common/self_keyword.rs
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
 
-use crate::{Node, Span};
+use crate::{Identifier, Node, Span};
 
 use serde::{Deserialize, Serialize};
 use std::fmt;
@@ -22,8 +22,9 @@ use std::fmt;
 /// The `self` keyword can view circuit values inside of a circuit function.
 /// Circuit values cannot be modified. To modify values use the `mut self` [MutSelfKeyword].
 #[derive(Clone, Serialize, Deserialize, Debug, PartialEq, Eq)]
+#[serde(transparent)]
 pub struct SelfKeyword {
-    pub span: Span,
+    pub identifier: Identifier,
 }
 
 impl fmt::Display for SelfKeyword {
@@ -34,10 +35,10 @@ impl fmt::Display for SelfKeyword {
 
 impl Node for SelfKeyword {
     fn span(&self) -> &Span {
-        &self.span
+        &self.identifier.span
     }
 
     fn set_span(&mut self, span: Span) {
-        self.span = span;
+        self.identifier.span = span;
     }
 }
diff --git a/ast/src/functions/input/input_variable.rs b/ast/src/functions/input/input_variable.rs
index f342cb3e1b..5ec9306aeb 100644
--- a/ast/src/functions/input/input_variable.rs
+++ b/ast/src/functions/input/input_variable.rs
@@ -96,9 +96,9 @@ impl Node for FunctionInput {
     fn span(&self) -> &Span {
         use FunctionInput::*;
         match self {
-            InputKeyword(keyword) => &keyword.span,
-            SelfKeyword(keyword) => &keyword.span,
-            MutSelfKeyword(keyword) => &keyword.span,
+            InputKeyword(keyword) => &keyword.identifier.span,
+            SelfKeyword(keyword) => &keyword.identifier.span,
+            MutSelfKeyword(keyword) => &keyword.identifier.span,
             Variable(variable) => &variable.span,
         }
     }
@@ -106,9 +106,9 @@ impl Node for FunctionInput {
     fn set_span(&mut self, span: Span) {
         use FunctionInput::*;
         match self {
-            InputKeyword(keyword) => keyword.span = span,
-            SelfKeyword(keyword) => keyword.span = span,
-            MutSelfKeyword(keyword) => keyword.span = span,
+            InputKeyword(keyword) => keyword.identifier.span = span,
+            SelfKeyword(keyword) => keyword.identifier.span = span,
+            MutSelfKeyword(keyword) => keyword.identifier.span = span,
             Variable(variable) => variable.span = span,
         }
     }
diff --git a/compiler/src/compiler.rs b/compiler/src/compiler.rs
index b2ff39b35a..d48fd71c28 100644
--- a/compiler/src/compiler.rs
+++ b/compiler/src/compiler.rs
@@ -224,7 +224,31 @@ impl<'a, F: PrimeField, G: GroupType<F>> Compiler<'a, F, G> {
         let content = fs::read_to_string(&self.main_file_path)
             .map_err(|e| CompilerError::FileReadError(self.main_file_path.clone(), e))?;
 
-        self.parse_program_from_string(&content)
+        self.parse_program_from_string(&content).map_err(|mut error| {
+            // Return a formatted error with file path and code text.
+
+            let path = match error.get_path().map(|x| x.to_string()) {
+                // Get the file path if it exists
+                Some(path) => path,
+
+                // If a file path does not exist, then insert the main file path.
+                None => match self.main_file_path.clone().into_os_string().into_string() {
+                    Err(e) => return CompilerError::FileStringError(e),
+                    Ok(path) => path,
+                },
+            };
+
+            // Resolve the code text using the file path.
+            let content = match self.resolve_content(&path) {
+                Err(e) => return e,
+                Ok(x) => x,
+            };
+
+            // Update the formatted error.
+            error.set_path(&path, &content[..]);
+
+            error
+        })
     }
 
     ///
diff --git a/compiler/src/errors/compiler.rs b/compiler/src/errors/compiler.rs
index be76b88c7f..a9d13e6b24 100644
--- a/compiler/src/errors/compiler.rs
+++ b/compiler/src/errors/compiler.rs
@@ -23,7 +23,7 @@ use leo_parser::SyntaxError;
 use leo_state::LocalDataVerificationError;
 
 use bincode::Error as SerdeError;
-use std::path::PathBuf;
+use std::{ffi::OsString, path::PathBuf};
 
 #[derive(Debug, Error)]
 pub enum CompilerError {
@@ -51,6 +51,9 @@ pub enum CompilerError {
     #[error("Cannot read from the provided file path '{:?}': {}", _0, _1)]
     FileReadError(PathBuf, std::io::Error),
 
+    #[error("Cannot parse file string `{:?}`", _0)]
+    FileStringError(OsString),
+
     #[error("{}", _0)]
     LocalDataVerificationError(#[from] LocalDataVerificationError),
 
diff --git a/compiler/tests/statements/iteration_input.in b/compiler/tests/statements/iteration_input.in
new file mode 100644
index 0000000000..8d27f19dde
--- /dev/null
+++ b/compiler/tests/statements/iteration_input.in
@@ -0,0 +1,2 @@
+[main]
+x: u8 = 1;
\ No newline at end of file
diff --git a/compiler/tests/statements/iteration_input.leo b/compiler/tests/statements/iteration_input.leo
new file mode 100644
index 0000000000..0ab62ab310
--- /dev/null
+++ b/compiler/tests/statements/iteration_input.leo
@@ -0,0 +1,5 @@
+function main(x: u8) {
+    for i in 0..x {
+        console.log("{}", i);
+    }
+}
\ No newline at end of file
diff --git a/compiler/tests/statements/iteration_variable.leo b/compiler/tests/statements/iteration_variable.leo
new file mode 100644
index 0000000000..d3d82b2664
--- /dev/null
+++ b/compiler/tests/statements/iteration_variable.leo
@@ -0,0 +1,7 @@
+function main() {
+    let x: u32 = 5;
+
+    for i in 0..x {
+        console.log("{}", i);
+    }
+}
\ No newline at end of file
diff --git a/compiler/tests/statements/mod.rs b/compiler/tests/statements/mod.rs
index 3aeb3f858b..8566d67576 100644
--- a/compiler/tests/statements/mod.rs
+++ b/compiler/tests/statements/mod.rs
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
 
-use crate::{assert_satisfied, expect_asg_error, generate_main_input, parse_program};
+use crate::{assert_satisfied, expect_asg_error, generate_main_input, parse_program, parse_program_with_input};
 use leo_ast::InputValue;
 
 pub mod conditional;
@@ -72,3 +72,20 @@ fn test_block() {
 
     assert_satisfied(program);
 }
+
+#[test]
+fn test_iteration_input() {
+    let input_string = include_str!("iteration_input.in");
+    let program_string = include_str!("iteration_input.leo");
+    let error = parse_program_with_input(program_string, input_string).err().unwrap();
+
+    expect_asg_error(error);
+}
+
+#[test]
+fn test_iteration_variable() {
+    let program_string = include_str!("iteration_variable.leo");
+    let program = parse_program(program_string).unwrap();
+
+    assert_satisfied(program);
+}
diff --git a/parser/src/parser/expression.rs b/parser/src/parser/expression.rs
index ec4df7c2cd..f8dbac1f0e 100644
--- a/parser/src/parser/expression.rs
+++ b/parser/src/parser/expression.rs
@@ -507,7 +507,7 @@ impl ParserContext {
     /// Returns an [`Expression`] AST node if the next tokens represent an
     /// circuit initialization expression.
     ///
-    pub fn parse_circuit_init(&mut self, ident: Identifier) -> SyntaxResult<Expression> {
+    pub fn parse_circuit_init(&mut self, identifier: Identifier) -> SyntaxResult<Expression> {
         self.expect(Token::LeftCurly)?;
         let mut members = vec![];
         let end_span;
@@ -535,8 +535,8 @@ impl ParserContext {
             }
         }
         Ok(Expression::CircuitInit(CircuitInitExpression {
-            span: &ident.span + &end_span,
-            name: ident,
+            span: &identifier.span + &end_span,
+            name: identifier,
             members,
         }))
     }
diff --git a/parser/src/parser/file.rs b/parser/src/parser/file.rs
index 36dca63852..f61f228976 100644
--- a/parser/src/parser/file.rs
+++ b/parser/src/parser/file.rs
@@ -309,11 +309,16 @@ impl ParserContext {
     ///
     pub fn parse_function_input(&mut self) -> SyntaxResult<FunctionInput> {
         if let Some(token) = self.eat(Token::Input) {
-            return Ok(FunctionInput::InputKeyword(InputKeyword { span: token.span }));
+            return Ok(FunctionInput::InputKeyword(InputKeyword {
+                identifier: Identifier {
+                    name: token.token.to_string(),
+                    span: token.span,
+                },
+            }));
         }
         let const_ = self.eat(Token::Const);
         let mutable = self.eat(Token::Mut);
-        let name = if let Some(token) = self.eat(Token::LittleSelf) {
+        let mut name = if let Some(token) = self.eat(Token::LittleSelf) {
             Identifier {
                 name: token.token.to_string(),
                 span: token.span,
@@ -326,11 +331,11 @@ impl ParserContext {
                 //error
             }
             if let Some(mutable) = &mutable {
-                return Ok(FunctionInput::MutSelfKeyword(MutSelfKeyword {
-                    span: &mutable.span + &name.span,
-                }));
+                name.span = &mutable.span + &name.span;
+                name.name = "mut self".to_string();
+                return Ok(FunctionInput::MutSelfKeyword(MutSelfKeyword { identifier: name }));
             }
-            return Ok(FunctionInput::SelfKeyword(SelfKeyword { span: name.span }));
+            return Ok(FunctionInput::SelfKeyword(SelfKeyword { identifier: name }));
         }
         self.expect(Token::Colon)?;
         let type_ = self.parse_type()?.0;