diff --git a/calc-example/calc/src/ir.rs b/calc-example/calc/src/ir.rs
index 7b422df5..773b8b67 100644
--- a/calc-example/calc/src/ir.rs
+++ b/calc-example/calc/src/ir.rs
@@ -1,6 +1,14 @@
 use ordered_float::OrderedFloat;
 use salsa::debug::DebugWithDb;
 
+// ANCHOR: input
+#[salsa::input]
+pub struct SourceProgram {
+    #[return_ref]
+    text: String,
+}
+// ANCHOR_END: input
+
 // ANCHOR: interned_ids
 #[salsa::interned]
 #[derive(Eq, PartialEq, Clone, Hash)]
diff --git a/calc-example/calc/src/main.rs b/calc-example/calc/src/main.rs
index a75e3a00..905d3d5a 100644
--- a/calc-example/calc/src/main.rs
+++ b/calc-example/calc/src/main.rs
@@ -1,6 +1,7 @@
 // ANCHOR: jar_struct
 #[salsa::jar(db = Db)]
 pub struct Jar(
+    crate::ir::SourceProgram,
     crate::ir::VariableId,
     crate::ir::FunctionId,
     crate::ir::Expression,
@@ -8,7 +9,6 @@ pub struct Jar(
     crate::ir::Function,
     crate::ir::Diagnostics,
     crate::parser::parse_statements,
-    crate::parser::source_text,
 );
 // ANCHOR_END: jar_struct
 
diff --git a/calc-example/calc/src/parser.rs b/calc-example/calc/src/parser.rs
index 032e1fe3..1a2e78b7 100644
--- a/calc-example/calc/src/parser.rs
+++ b/calc-example/calc/src/parser.rs
@@ -1,22 +1,15 @@
 use ordered_float::OrderedFloat;
 
 use crate::ir::{
-    Diagnostic, Diagnostics, Expression, ExpressionData, Function, FunctionId, Op, Statement,
-    StatementData, VariableId,
+    Diagnostic, Diagnostics, Expression, ExpressionData, Function, FunctionId, Op, SourceProgram,
+    Statement, StatementData, VariableId,
 };
 
-// ANCHOR: source_text
-#[salsa::memoized(return_ref)]
-pub fn source_text(_db: &dyn crate::Db) -> String {
-    panic!("input")
-}
-// ANCHOR_END: source_text
-
 // ANCHOR: parse_statements
 #[salsa::memoized(return_ref)]
-pub fn parse_statements(db: &dyn crate::Db) -> Vec<Statement> {
+pub fn parse_statements(db: &dyn crate::Db, source: SourceProgram) -> Vec<Statement> {
     // Get the source text from the database
-    let source_text = source_text(db);
+    let source_text = source.text(db);
 
     // Create the parser
     let mut parser = Parser {
@@ -339,14 +332,14 @@ fn parse_string(source_text: &str) -> String {
     // Create the database
     let mut db = crate::db::Database::default();
 
-    // Set the source_text value
-    source_text::set(&mut db, source_text.to_string());
+    // Create the source program
+    let source_program = SourceProgram::new(&mut db, source_text.to_string());
 
     // Invoke the parser
-    let statements = parse_statements(&db);
+    let statements = parse_statements(&db, source_program);
 
     // Read out any diagnostics
-    let accumulated = parse_statements::accumulated::<Diagnostics>(&db);
+    let accumulated = parse_statements::accumulated::<Diagnostics>(&db, source_program);
 
     // Format the result as a string and return it
     format!("{:#?}", (statements, accumulated).debug(&db))