cleanup unwrap

compiler/module/src/lib.rs

@@ -4,6 +4,7 @@
 
 pub mod ident;
 pub mod low_level;
+pub mod module_err;
 pub mod operator;
 pub mod symbol;
 

compiler/module/src/module_err.rs

@@ -0,0 +1,18 @@
+use snafu::{Backtrace, Snafu};
+
+#[derive(Debug, Snafu)]
+#[snafu(visibility(pub))]
+pub enum ModuleError {
+    #[snafu(display(
+        "ModuleIdNotFound: I could not find the ModuleId {} in Interns.all_ident_ids: {}.",
+        module_id,
+        all_ident_ids
+    ))]
+    ModuleIdNotFound {
+        module_id: String,
+        all_ident_ids: String,
+        backtrace: Backtrace,
+    },
+}
+
+pub type ModuleResult<T, E = ModuleError> = std::result::Result<T, E>;

compiler/module/src/symbol.rs

@@ -1,7 +1,9 @@
 use crate::ident::{Ident, ModuleName};
+use crate::module_err::{ModuleIdNotFound, ModuleResult};
 use roc_collections::all::{default_hasher, MutMap, SendMap};
 use roc_ident::IdentStr;
 use roc_region::all::Region;
+use snafu::OptionExt;
 use std::collections::HashMap;
 use std::{fmt, u32};
 
@@ -253,6 +255,15 @@ impl Interns {
     pub fn from_index(module_id: ModuleId, ident_id: u32) -> Symbol {
         Symbol::new(module_id, IdentId(ident_id))
     }
+
+    pub fn get_module_ident_ids(&self, module_id: &ModuleId) -> ModuleResult<&IdentIds> {
+        self.all_ident_ids
+            .get(module_id)
+            .with_context(|| ModuleIdNotFound {
+                module_id: format!("{:?}", module_id),
+                all_ident_ids: format!("{:?}", self.all_ident_ids),
+            })
+    }
 }
 
 #[cfg(debug_assertions)]