Another round of optimization

tests/forth/harness.rs

@@ -4,7 +4,7 @@ use rand::SeedableRng;
 use std::collections::HashMap;
 use std::sync::{Arc, Mutex};
 
-pub fn default_ctx() -> StepContext {
+pub fn default_ctx() -> StepContext<'static> {
     StepContext {
         step: 0,
         beat: 0.0,
@@ -19,10 +19,12 @@ pub fn default_ctx() -> StepContext {
         fill: false,
         nudge_secs: 0.0,
         cc_access: None,
+        speed_key: "__speed_0_0__",
+        chain_key: "__chain_0_0__",
     }
 }
 
-pub fn ctx_with(f: impl FnOnce(&mut StepContext)) -> StepContext {
+pub fn ctx_with(f: impl FnOnce(&mut StepContext<'static>)) -> StepContext<'static> {
     let mut ctx = default_ctx();
     f(&mut ctx);
     ctx