flatten the instruction dispatch loop

Cargo.lock

@@ -378,6 +378,15 @@ dependencies = [
  "new_debug_unreachable",
 ]
 
+[[package]]
+name = "fxhash"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c31b6d751ae2c7f11320402d34e41349dd1016f8d5d45e48c4312bc8625af50c"
+dependencies = [
+ "byteorder",
+]
+
 [[package]]
 name = "generic-array"
 version = "0.12.4"
@@ -436,6 +445,15 @@ version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
 
+[[package]]
+name = "heck"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d621efb26863f0e9924c6ac577e8275e5e6b77455db64ffa6c65c904e9e132c"
+dependencies = [
+ "unicode-segmentation",
+]
+
 [[package]]
 name = "hostname"
 version = "0.3.1"
@@ -471,6 +489,20 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "instructions-template"
+version = "0.1.0"
+dependencies = [
+ "indexmap",
+ "proc-macro2 1.0.32",
+ "quote 1.0.10",
+ "strum",
+ "strum_macros",
+ "syn 1.0.81",
+ "to-syn-value",
+ "to-syn-value_derive",
+]
+
 [[package]]
 name = "iovec"
 version = "0.1.4"
@@ -1325,6 +1357,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "rustversion"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2cc38e8fa666e2de3c4aba7edeb5ffc5246c1c2ed0e3d17e560aeeba736b23f"
+
 [[package]]
 name = "rustyline"
 version = "9.0.0"
@@ -1392,9 +1430,11 @@ dependencies = [
  "crossterm",
  "dirs-next",
  "divrem",
+ "fxhash",
  "git-version",
  "hostname",
  "indexmap",
+ "instructions-template",
  "lazy_static",
  "lexical",
  "libc",
@@ -1655,6 +1695,25 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b1884d1bc09741d466d9b14e6d37ac89d6909cbcac41dd9ae982d4d063bbedfc"
 
+[[package]]
+name = "strum"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cae14b91c7d11c9a851d3fbc80a963198998c2a64eec840477fa92d8ce9b70bb"
+
+[[package]]
+name = "strum_macros"
+version = "0.23.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5bb0dc7ee9c15cea6199cde9a127fa16a4c5819af85395457ad72d68edc85a38"
+dependencies = [
+ "heck",
+ "proc-macro2 1.0.32",
+ "quote 1.0.10",
+ "rustversion",
+ "syn 1.0.81",
+]
+
 [[package]]
 name = "subtle"
 version = "1.0.0"
@@ -1724,6 +1783,23 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "to-syn-value"
+version = "0.1.0"
+dependencies = [
+ "syn 1.0.81",
+ "to-syn-value_derive",
+]
+
+[[package]]
+name = "to-syn-value_derive"
+version = "0.1.0"
+dependencies = [
+ "proc-macro2 1.0.32",
+ "quote 1.0.10",
+ "syn 1.0.81",
+]
+
 [[package]]
 name = "typenum"
 version = "1.14.0"