fix(lib)!: clean up Error type variants, prefer error objects to strings

crates/lib/src/compiler/libquil.rs

@@ -202,14 +202,14 @@ mod test {
         assert_eq!(output.program.to_quil_or_debug(), EXPECTED_H0_OUTPUT);
     }
 
-    const BELL_STATE: &str = r##"DECLARE ro BIT[2]
+    const BELL_STATE: &str = r"DECLARE ro BIT[2]
 
 H 0
 CNOT 0 1
 
 MEASURE 0 ro[0]
 MEASURE 1 ro[1]
-"##;
+";
 
     #[tokio::test]
     async fn test_print_isa() {

crates/lib/src/executable.rs

@@ -5,12 +5,10 @@ use std::borrow::Cow;
 use std::collections::HashMap;
 use std::num::NonZeroU16;
 use std::sync::Arc;
-use std::time::Duration;
 
-use qcs_api_client_common::configuration::LoadError;
 use quil_rs::quil::ToQuilError;
 
-use crate::client::Qcs;
+use crate::client::{GrpcClientError, Qcs};
 use crate::compiler::quilc::{self, CompilerOpts};
 use crate::execution_data::{self, ResultData};
 use crate::qpu::api::{ExecutionOptions, JobId};
@@ -603,29 +601,9 @@ impl<'execution> Executable<'_, 'execution> {
 /// [`Executable::execute_on_qvm`]..
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
-    /// Communicating with QCS requires appropriate settings and secrets files. By default, these
-    /// should be `$HOME/.qcs/settings.toml` and `$HOME/.qcs/secrets.toml`, though those files can
-    /// be overridden by setting the `QCS_SETTINGS_FILE_PATH` and `QCS_SECRETS_FILE_PATH`
-    /// environment variables.
-    ///
-    /// This error can occur when one of those files is required but missing or there is a problem
-    /// with the contents of those files.
-    #[error("There was a problem related to your QCS settings: {0}")]
-    Settings(String),
-    /// This error occurs when the SDK was unable to authenticate a request to QCS. This could mean
-    /// that your credentials are invalid or expired, or that you do not have access to the requested
-    /// QPU.
-    #[error("Could not authenticate a request to QCS for the requested QPU.")]
-    Authentication,
     /// An API error occurred while connecting to the QPU.
     #[error("An API error occurred while connecting to the QPU: {0}")]
     QpuApiError(#[from] qpu::api::QpuApiError),
-    /// This happens when the QPU is down for maintenance and not accepting new jobs. If you receive
-    /// this error, internal compilation caches will have been cleared as programs should be recompiled
-    /// with new settings after a maintenance window. If you are mid-experiment, you might want to
-    /// start over.
-    #[error("QPU currently unavailable, retry after {} seconds", .0.as_secs())]
-    QpuUnavailable(Duration),
     /// Indicates a problem connecting to an external service. Check your network connection and
     /// ensure that any required local services (e.g., `qvm` or `quilc`) are running.
     #[error("Error connecting to service {0:?}")]
@@ -643,29 +621,18 @@ pub enum Error {
     Compilation(String),
     /// There was a problem when translating the Quil program.
     #[error("There was a problem translating the Quil program: {0}")]
-    Translation(String),
+    Translation(GrpcClientError),
     /// There was a problem when rewriting parameter arithmetic in the Quil program.
     #[error("There was a problem rewriting parameter arithmetic in the Quil program: {0}")]
     RewriteArithmetic(#[from] rewrite_arithmetic::Error),
     /// There was a problem when substituting parameters in the Quil program.
     #[error("There was a problem substituting parameters in the Quil program: {0}")]
     Substitution(String),
-    /// The Quil program is missing readout sources.
-    #[error("The Quil program is missing readout sources")]
-    MissingRoSources,
     /// This error returns when a runtime check that _should_ always pass fails. This most likely
     /// indicates a bug in the SDK and should be reported to
     /// [GitHub](https://github.com/rigetti/qcs-sdk-rust/issues),
     #[error("An unexpected error occurred, please open an issue on GitHub: {0:?}")]
     Unexpected(String),
-    /// Occurs when [`Executable::retrieve_results`] is called with an invalid [`JobHandle`].
-    /// Calling functions on [`Executable`] between [`Executable::submit_to_qpu`] and
-    /// [`Executable::retrieve_results`] can invalidate the handle.
-    #[error("The job handle was not valid")]
-    InvalidJobHandle,
-    /// Occurs when failing to construct a [`Qcs`] client.
-    #[error("The QCS client configuration failed to load")]
-    QcsConfigLoadFailure(#[from] LoadError),
 }
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
@@ -700,7 +667,7 @@ impl From<ExecutionError> for Error {
         match err {
             ExecutionError::Unexpected(inner) => Self::Unexpected(format!("{inner:?}")),
             ExecutionError::Quilc { .. } => Self::Connection(Service::Quilc),
-            ExecutionError::QcsClient(v) => Self::Unexpected(format!("{v:?}")),
+            ExecutionError::Translation(e) => Self::Translation(e),
             ExecutionError::Isa(v) => Self::Unexpected(format!("{v:?}")),
             ExecutionError::ReadoutParse(v) => Self::Unexpected(format!("{v:?}")),
             ExecutionError::Quil(e) => Self::Quil(e),

crates/lib/src/lib.rs

@@ -56,6 +56,9 @@ pub use execution_data::{
 };
 pub use register_data::RegisterData;
 
+// Re-export tonic for consumers to use.
+pub use tonic;
+
 pub mod client;
 pub mod compiler;
 pub mod diagnostics;

crates/lib/src/qpu/execution.rs

@@ -49,8 +49,8 @@ pub(crate) enum Error {
     Unexpected(#[from] Unexpected),
     #[error("Problem communicating with quilc at {uri}: {details}")]
     Quilc { uri: String, details: String },
-    #[error("Problem using QCS API: {0}")]
-    QcsClient(#[from] GrpcClientError),
+    #[error("Problem translating using QCS API: {0}")]
+    Translation(#[from] GrpcClientError),
     #[error("Problem fetching ISA: {0}")]
     Isa(#[from] GetIsaError),
     #[error("Problem parsing memory readout: {0}")]

crates/lib/src/qpu/rewrite_arithmetic.rs

@@ -367,6 +367,8 @@ impl RewrittenProgram {
     }
 }
 
+pub(crate) type Substitutions = IndexSet<Expression>;
+
 #[cfg(test)]
 mod describe_rewrite_arithmetic {
     use std::str::FromStr;
@@ -559,5 +561,3 @@ SHIFT-PHASE 0 "rf" __SUBST[0]
         insta::assert_snapshot!(substitutions[0].to_quil_or_debug());
     }
 }
-
-pub(crate) type Substitutions = IndexSet<Expression>;

deny.toml

@@ -28,6 +28,9 @@ ignore = [
     "RUSTSEC-2023-0052",  # Introduced by transitive dependency `webpki`.
                           # `hyper-proxy`, then `qcs-api-client-rust` need to update in order to remove
                           # `webpki`.
+    "RUSTSEC-2024-0006"   # Introduced by transitive dependency `shlex`.
+                          # `bindgen`, then `libquil-sys` need to update in order to get a version
+                          # of `shlex` >= 1.3.0.
 ]
 
 # This section is considered when running `cargo deny check licenses`