better command aliases (roc-lang#412)

Author: Anton-4

flake.nix

@@ -30,9 +30,16 @@
         rust =
           pkgs.rust-bin.fromRustupToolchainFile "${toString ./rust-toolchain.toml}";
 
-        aliases = ''
-          alias buildcmd='bash jump-start.sh && roc ./build.roc -- --roc roc'
-          alias testcmd='export ROC=roc && export EXAMPLES_DIR=./examples/ && ./ci/all_tests.sh'
+        shellFunctions = ''
+          buildcmd() {
+            bash jump-start.sh && roc ./build.roc -- --roc roc
+          }
+          export -f buildcmd
+
+          testcmd() {
+            export EXAMPLES_DIR=./examples/ && ./ci/all_tests.sh
+          }
+          export -f testcmd
         '';
 
         linuxInputs = with pkgs;
@@ -72,10 +79,15 @@
             if pkgs.stdenv.isLinux then "${pkgs.glibc.out}/lib" else "";
 
           shellHook = ''
-            ${aliases}
+            export ROC=roc
+
+            ${shellFunctions}
             
-            echo "Some convenient command aliases:"
-            echo "${aliases}" | grep -E "alias .*" -o | sed 's/alias /  /' | sed 's/=/ = /'
+            echo "Some convenient commands:"
+            echo "${shellFunctions}" | grep -E '^\s*[a-zA-Z_][a-zA-Z0-9_]*\(\)' | sed 's/().*//' | sed 's/^[[:space:]]*/  /' | while read func; do
+              body=$(echo "${shellFunctions}" | sed -n "/''${func}()/,/^[[:space:]]*}/p" | sed '1d;$d' | tr '\n' ';' | sed 's/;$//' | sed 's/[[:space:]]*$//')
+              echo "  $func = $body"
+            done
             echo ""
           '';
         };