Reintroduce multi-language transpilation with Tongues

.github/workflows/ci.yml

@@ -16,11 +16,22 @@ jobs:
 
       - uses: extractions/setup-just@v2
 
-      - name: Set up Homebrew
-        uses: Homebrew/actions/setup-homebrew@master
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
 
       - name: Install Tongues
-        run: brew install ldayton/tongues/tongues
+        env:
+          TONGUES_VERSION: v0.2.3
+        run: |
+          mkdir -p "$HOME/.local/lib/tongues/lib" "$HOME/.local/lib/tongues/bin" "$HOME/.local/bin"
+          curl -sSfL "https://github.com/ldayton/Tongues/releases/download/${TONGUES_VERSION}/tongues.js" \
+              -o "$HOME/.local/lib/tongues/lib/tongues.js"
+          curl -sSfL "https://raw.githubusercontent.com/ldayton/Tongues/${TONGUES_VERSION}/tongues/bin/tongues.js" \
+              -o "$HOME/.local/lib/tongues/bin/tongues.js"
+          printf '#!/bin/sh\nexec node %s/.local/lib/tongues/bin/tongues.js "$@"\n' "$HOME" > "$HOME/.local/bin/tongues"
+          chmod +x "$HOME/.local/bin/tongues"
+          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
 
       - name: Job summary
         run: |

.gitignore

@@ -16,3 +16,4 @@ tools/bash-oracle/bin/negation-cmdsub.txt
 /bugs.tests
 scalene-profile.html
 src/cmd/debug-test/
+.out/

justfile

@@ -1,5 +1,7 @@
 set shell := ["bash", "-o", "pipefail", "-cu"]
 
+export VIRTUAL_ENV := ""
+
 # --- Configuration ---
 project := "parable"
 run_id := `head -c 16 /dev/urandom | xxd -p`
@@ -36,7 +38,7 @@ src-verify-lock: (_banner "src-verify-lock")
 check-tongues: (_banner "check-tongues")
     #!/usr/bin/env bash
     set -euo pipefail
-    required="0.2.2"
+    required="0.2.3"
     if ! command -v tongues &>/dev/null; then
         echo "FAIL: tongues not found. Install with: brew install ldayton/tap/tongues"
         exit 1
@@ -68,6 +70,102 @@ check: _check-parallel
 [group: 'ci']
 check-quick: src-test
 
+# --- Transpiled backends ---
+
+# SHA256 of source file (truncated to 16 chars)
+[private]
+_src-checksum:
+    @cat src/parable.py | { sha256sum 2>/dev/null || shasum -a 256; } | cut -c1-16
+
+# Transpile source to target language (skips if unchanged)
+[private]
+_transpile target:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    declare -A ext=([python]=py [ruby]=rb [perl]=pl [javascript]=js [java]=java)
+    e=${ext[{{target}}]}
+    out=".out/parable.$e"
+    sum_file=".out/.sum-{{target}}"
+    current=$(just -f {{justfile()}} _src-checksum)
+    cached=$(cat "$sum_file" 2>/dev/null || echo "")
+    if [ -f "$out" ] && [ "$current" = "$cached" ]; then
+        printf '\033[33m[transpile-{{target}}] up to date\033[0m\n'
+        exit 0
+    fi
+    rm -f "$sum_file"
+    printf '\033[32m[transpile-{{target}}]\033[0m\n'
+    start=$SECONDS
+    mkdir -p .out
+    tongues --target {{target}} -o "$out" src/parable.py
+    case "{{target}}" in
+        javascript) echo 'module.exports = { parse, ParseError, MatchedPairError };' >> "$out" ;;
+        perl)       echo '1;' >> "$out" ;;
+    esac
+    printf '\033[32m[transpile-{{target}}] %ds\033[0m\n' "$((SECONDS - start))"
+    echo "$current" > "$sum_file"
+
+# Run transpiled tests for a target language
+[private]
+_run-lang-tests target:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    printf '\033[32m[lang-{{target}}]\033[0m\n'
+    start=$SECONDS
+    case "{{target}}" in
+        javascript)
+            PARABLE_PATH="$(pwd)/.out" node tests/transpiled/javascript/run-tests.js tests
+            ;;
+        python)
+            PYTHONPATH=.out uv run python tests/transpiled/python/run_tests.py tests
+            ;;
+        java)
+            mkdir -p .out/java-classes
+            cp .out/parable.java .out/java-classes/Main.java
+            javac -encoding UTF-8 .out/java-classes/Main.java -d .out/java-classes
+            javac -encoding UTF-8 -cp .out/java-classes tests/transpiled/java/RunTests.java -d .out/java-classes
+            java -cp .out/java-classes RunTests tests
+            ;;
+        perl)
+            perl -I.out tests/transpiled/perl/run_tests.pl tests
+            ;;
+        ruby)
+            ruby -I.out tests/transpiled/ruby/run_tests.rb tests
+            ;;
+        *)
+            echo "Unknown target: {{target}}"
+            exit 1
+            ;;
+    esac
+    printf '\033[32m[lang-{{target}}] %ds\033[0m\n' "$((SECONDS - start))"
+
+# Transpile and run tests in target language
+# Usage: just lang javascript
+[group: 'backends']
+lang target: check-tongues (_transpile target) (_run-lang-tests target)
+
+# Transpile using local Tongues dev source and run tests
+# Usage: just lang-dev javascript
+[group: 'backends']
+lang-dev target: (_transpile-dev target) (_run-lang-tests target)
+
+# Transpile using local Tongues source (no caching)
+[private]
+_transpile-dev target:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    declare -A ext=([python]=py [ruby]=rb [perl]=pl [javascript]=js [java]=java)
+    e=${ext[{{target}}]}
+    out=".out/parable.$e"
+    mkdir -p .out
+    printf '\033[32m[transpile-{{target}} (dev)]\033[0m\n'
+    start=$SECONDS
+    python3 ~/source/Tongues/tongues/bin/tongues --target {{target}} -o "$out" src/parable.py
+    case "{{target}}" in
+        javascript) echo 'module.exports = { parse, ParseError, MatchedPairError };' >> "$out" ;;
+        perl)       echo '1;' >> "$out" ;;
+    esac
+    printf '\033[32m[transpile-{{target}} (dev)] %ds\033[0m\n' "$((SECONDS - start))"
+
 # --- Tools ---
 
 # Run the fuzzer (e.g., just fuzz char --stop-after 10)