Get rid of anyhow.

Cargo.lock

@@ -2,20 +2,69 @@
 # It is not intended for manual editing.
 version = 4
 
-[[package]]
-name = "anyhow"
-version = "1.0.102"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
-
 [[package]]
 name = "j7s_diagnostics"
 version = "0.1.0"
 dependencies = [
- "anyhow",
  "limbo_graph",
+ "thiserror",
 ]
 
 [[package]]
 name = "limbo_graph"
 version = "0.1.0"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.46"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dfbc457d0c7a0759a614551b11a6409e5951f6c7537be1f1b7682b9ae9230368"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.118"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b9ae57f904213ebb649ce6895b8a66c66f0203b9319718f69a5612a065b1422"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "thiserror"
+version = "2.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4288b5bcbc7920c07a1149a35cf9590a2aa808e0bc1eafaade0b80947865fbc4"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "2.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ebc4ee7f67670e9b64d05fa4253e753e016c6c95ff35b89b7941d6b856dec1d5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"

Cargo.toml

@@ -4,5 +4,5 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-anyhow = { version = "1.0", default-features = false }
 limbo_graph = { path = "../limbo_graph" }
+thiserror = { version = "2.0.18", default-features = false }

src/diagnostic_node.rs

@@ -9,7 +9,7 @@
 // defined by the Mozilla Public License, v. 2.0.
 //
 use crate::DiagnosticStatus;
-use anyhow::anyhow;
+use crate::error::{Error, Result};
 
 #[derive(Clone)]
 pub enum DiagnosticNode {
@@ -30,10 +30,10 @@ impl DiagnosticNode {
         }
     }
 
-    pub fn value(&self) -> anyhow::Result<&DiagnosticStatus> {
+    pub fn value(&self) -> Result<&DiagnosticStatus> {
         match self {
             Self::DiagnosticStatus(value) => Ok(value),
-            _ => Err(anyhow!("Can't get value of root key.")),
+            _ => Err(Error::from_msg("Can't get value of root key.")),
         }
     }
 }

src/error.rs

@@ -0,0 +1,28 @@
+//
+// Copyright 2026 James Pace
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+//
+// This Source Code Form is "Incompatible With Secondary Licenses", as
+// defined by the Mozilla Public License, v. 2.0.
+//
+
+use alloc::string::{String, ToString};
+
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error("GraphError: {0}")]
+    GraphError(#[from] limbo_graph::Error),
+    #[error("Error from j7s_diagnostics: {0}")]
+    Msg(String),
+}
+
+impl Error {
+    pub fn from_msg(msg: &str) -> Self {
+        Error::Msg(msg.to_string())
+    }
+}
+
+pub type Result<T, E = Error> = core::result::Result<T, E>;

src/lib.rs

@@ -9,25 +9,24 @@
 // defined by the Mozilla Public License, v. 2.0.
 //
 
-// TODO: Remove anyhow.
 #![no_std]
 #![allow(unused_imports)]
 extern crate alloc;
 
 mod diagnostic_node;
 mod diagnostic_status;
+mod error;
 mod name_parsing;
 
-use anyhow::anyhow;
-
-use crate::alloc::string::ToString;
 use alloc::borrow::ToOwned;
 use alloc::collections::BTreeMap;
 use alloc::collections::VecDeque;
 use alloc::string::String;
+use alloc::string::ToString;
 use alloc::vec::Vec;
 
 pub use crate::diagnostic_status::*;
+pub use crate::error::*;
 
 use crate::diagnostic_node::*;
 use crate::name_parsing::*;
@@ -47,13 +46,13 @@ impl DiagnosticGraph {
         return self.graph.root_key();
     }
 
-    pub fn value_of(&self, key: &limbo_graph::Key) -> anyhow::Result<DiagnosticStatus> {
+    pub fn value_of(&self, key: &limbo_graph::Key) -> Result<DiagnosticStatus> {
         let graph_value = self.graph.value_of(key)?;
         let result = graph_value.value()?;
         Ok(result.clone())
     }
 
-    pub fn children_of(&self, key: &limbo_graph::Key) -> anyhow::Result<Vec<limbo_graph::Key>> {
+    pub fn children_of(&self, key: &limbo_graph::Key) -> Result<Vec<limbo_graph::Key>> {
         let result = self.graph.children_of(key)?;
         Ok(result)
     }
@@ -62,9 +61,9 @@ impl DiagnosticGraph {
         &self,
         parent: &limbo_graph::Key,
         desired_child_name: &str,
-    ) -> anyhow::Result<Option<limbo_graph::Key>> {
+    ) -> Result<Option<limbo_graph::Key>> {
         if !name_is_basic(&desired_child_name.to_owned()) {
-            return Err(anyhow!("desired child name must be basic."));
+            return Err(Error::from_msg("desired child name must be basic."));
         }
         let all_children = self.children_of(parent)?;
         for child in all_children.iter() {
@@ -76,10 +75,7 @@ impl DiagnosticGraph {
         return Ok(None);
     }
 
-    pub fn key_from_full_name(
+    pub fn key_from_full_name(&self, full_name: &String) -> Result<Option<limbo_graph::Key>> {
-        &self,
-        full_name: &String,
-    ) -> anyhow::Result<Option<limbo_graph::Key>> {
         let name_as_vec = split_name(&full_name);
 
         let mut cur_base_key = self.graph.root_key();
@@ -94,7 +90,7 @@ impl DiagnosticGraph {
         return Ok(Some(cur_base_key));
     }
 
-    pub fn full_name_from_key(&self, key: &limbo_graph::Key) -> anyhow::Result<String> {
+    pub fn full_name_from_key(&self, key: &limbo_graph::Key) -> Result<String> {
         let path_to_key = self.graph.backtrack_from_key(key)?;
         let mut full_name = String::new();
 
@@ -112,7 +108,7 @@ impl DiagnosticGraph {
     pub fn value_from_name(
         &self,
         full_name: &String,
-    ) -> anyhow::Result<Option<(DiagnosticStatus, limbo_graph::Key)>> {
+    ) -> Result<Option<(DiagnosticStatus, limbo_graph::Key)>> {
         let key = self.key_from_full_name(full_name)?;
         if key.is_none() {
             return Ok(None);
@@ -123,7 +119,7 @@ impl DiagnosticGraph {
         return Ok(Some((value, key)));
     }
 
-    pub fn add_status(&mut self, status: DiagnosticStatus) -> anyhow::Result<()> {
+    pub fn add_status(&mut self, status: DiagnosticStatus) -> Result<()> {
         // If I'm basic I just need to be added as a child of the root.
         if status.name_is_basic() {
             self.graph.add(
@@ -154,7 +150,7 @@ impl DiagnosticGraph {
                 let child_node = self.graph.value_of(&child)?;
                 if child_node.is_root() {
                     // A child node can't be root.
-                    return Err(anyhow!("A child node can't be root!"));
+                    return Err(Error::from_msg("A child node can't be root!"));
                 }
                 if child_node.value()?.name() == *parent_name {
                     // The child node matched the parent we were looking for.
@@ -195,14 +191,14 @@ impl DiagnosticGraph {
         Ok(())
     }
 
-    pub fn add_status_vec(&mut self, statuses: &Vec<DiagnosticStatus>) -> anyhow::Result<()> {
+    pub fn add_status_vec(&mut self, statuses: &Vec<DiagnosticStatus>) -> Result<()> {
         for status in statuses {
             self.add_status(status.clone())?;
         }
         Ok(())
     }
 
-    pub fn reconcile_levels(&mut self) -> anyhow::Result<()> {
+    pub fn reconcile_levels(&mut self) -> Result<()> {
         let leaf_keys = self.graph.find_leaf_keys()?;
 
         'leaf_key_loop: for leaf_key in leaf_keys.iter() {
@@ -238,7 +234,7 @@ impl DiagnosticGraph {
         Ok(())
     }
 
-    pub fn export_graph(&self) -> anyhow::Result<Vec<DiagnosticStatus>> {
+    pub fn export_graph(&self) -> Result<Vec<DiagnosticStatus>> {
         let keys_in_order = self.graph.get_keys_by_depth()?;
 
         let mut statuses = Vec::<DiagnosticStatus>::new();
@@ -288,7 +284,7 @@ mod tests {
     }
 
     #[test]
-    fn add_one_to_graph() -> anyhow::Result<()> {
+    fn add_one_to_graph() -> Result<()> {
         let mut graph = DiagnosticGraph::new();
         graph.add_status(make_a_status_with_name("/a/b/c"))?;
 
@@ -315,7 +311,7 @@ mod tests {
     }
 
     #[test]
-    fn add_multiple_to_graph() -> anyhow::Result<()> {
+    fn add_multiple_to_graph() -> Result<()> {
         let statuses = vec![
             make_a_status_with_name("/a"),
             make_a_status_with_name("/a/b"),
@@ -354,7 +350,7 @@ mod tests {
     }
 
     #[test]
-    fn key_name_connections() -> anyhow::Result<()> {
+    fn key_name_connections() -> Result<()> {
         let statuses = vec![
             make_a_status_with_name("/a"),
             make_a_status_with_name("/a/b"),
@@ -381,7 +377,7 @@ mod tests {
     }
 
     #[test]
-    fn reconcile_graph() -> anyhow::Result<()> {
+    fn reconcile_graph() -> Result<()> {
         let statuses = vec![
             make_a_status_with_name_and_level("/a", DiagnosticLevel::UNSET),
             make_a_status_with_name_and_level("/a/b", DiagnosticLevel::UNSET),