Use TryFrom to handle enum errors, get definition loading working with demo definitions

src/products/create_products.rs

@@ -10,7 +10,10 @@ use polars::lazy::dsl::*;
 use polars::prelude::*;
 use serde::Serialize;
 
-use super::csv::{read_definitions, BuildFrom, Component, ConstraintType, Definition, SourceType};
+use super::csv::{
+    read_definitions, BuildFrom, Component, ComponentSourceType, ConstraintType, Definition,
+    SourceType,
+};
 
 // TODO: Polars suggests this, but docs suggest it doesn't have very good platform support
 //use jemallocator::Jemalloc;
@@ -251,7 +254,7 @@ pub fn build_encounters_polars(
             .iter()
             .any(|f| f.source_type == SourceType::Patient)
         || definition.components.iter().any(|c| match c {
-            Component::Field(source, _) => source == "P",
+            Component::Field(source, _) => *source == ComponentSourceType::Patient,
             _ => false,
         })
     {