Merge pull request #95 from benbernard/feature/template-compound-and-polyglot

benbernard · web-flow · commit ff9d03066829 · 2026-02-24T15:29:25.000-08:00
feat: {{}} compound assignments and polyglot support
diff --git a/src/Executor.ts b/src/Executor.ts
@@ -93,22 +93,36 @@ interface CompiledSnippet {
  *
  * {{foo/bar}} becomes calls to the __get helper function.
  * {{foo/bar}} = value becomes calls to the __set helper function.
+ * {{foo/bar}} += value becomes __set(R, "foo/bar", __get(R, "foo/bar") + value)
+ *
+ * The recordVar parameter controls the variable name used in generated code
+ * (e.g. "r" for JS/Python, "$r" for Perl).
  */
-export function transformCode(code: string): string {
-  // Replace {{keyspec}} = value with __set(r, "keyspec", value)
-  // Negative lookahead (?!=) ensures == and === are not matched as assignment
+export function transformCode(code: string, recordVar = "r"): string {
+  // Step 1: Replace compound assignments like {{ks}} += val
+  // Operators listed longest-first for correct matching
   let transformed = code.replace(
+    /\{\{(.*?)\}\}\s*(\*\*|>>>|>>|<<|\?\?|\/\/|\|\||&&|\+|-|\*|\/|%|&|\||\^)=\s*([^;,\n]+)/g,
+    (_match, keyspec: string, op: string, value: string) => {
+      const ks = JSON.stringify(keyspec);
+      return `__set(${recordVar}, ${ks}, __get(${recordVar}, ${ks}) ${op} ${value.trim()})`;
+    }
+  );
+
+  // Step 2: Replace simple assignments like {{ks}} = val
+  // Negative lookahead (?!=) ensures == and === are not matched
+  transformed = transformed.replace(
     /\{\{(.*?)\}\}\s*=(?!=)\s*([^;,\n]+)/g,
     (_match, keyspec: string, value: string) => {
-      return `__set(r, ${JSON.stringify(keyspec)}, ${value.trim()})`;
+      return `__set(${recordVar}, ${JSON.stringify(keyspec)}, ${value.trim()})`;
     }
   );
 
-  // Replace remaining {{keyspec}} with __get(r, "keyspec")
+  // Step 3: Replace remaining {{keyspec}} reads
   transformed = transformed.replace(
     /\{\{(.*?)\}\}/g,
     (_match, keyspec: string) => {
-      return `__get(r, ${JSON.stringify(keyspec)})`;
+      return `__get(${recordVar}, ${JSON.stringify(keyspec)})`;
     }
   );
 
diff --git a/src/snippets/PerlSnippetRunner.ts b/src/snippets/PerlSnippetRunner.ts
@@ -17,6 +17,7 @@ import type {
   SnippetMode,
 } from "./SnippetRunner.ts";
 import { groupResponses } from "./SnippetRunner.ts";
+import { transformCode } from "../Executor.ts";
 
 const SNIPPETS_DIR = dirname(fileURLToPath(import.meta.url));
 const RUNNER_DIR = join(SNIPPETS_DIR, "perl");
@@ -28,7 +29,7 @@ export class PerlSnippetRunner implements SnippetRunner {
   #mode: SnippetMode = "eval";
 
   async init(code: string, context: SnippetContext): Promise<void> {
-    this.#code = code;
+    this.#code = transformCode(code, "$r");
     this.#mode = context.mode;
   }
 
diff --git a/src/snippets/PythonSnippetRunner.ts b/src/snippets/PythonSnippetRunner.ts
@@ -18,6 +18,7 @@ import type {
   SnippetMode,
 } from "./SnippetRunner.ts";
 import { groupResponses } from "./SnippetRunner.ts";
+import { transformCode } from "../Executor.ts";
 
 const SNIPPETS_DIR = dirname(fileURLToPath(import.meta.url));
 const RUNNER_DIR = join(SNIPPETS_DIR, "python");
@@ -29,7 +30,7 @@ export class PythonSnippetRunner implements SnippetRunner {
   #mode: SnippetMode = "eval";
 
   async init(code: string, context: SnippetContext): Promise<void> {
-    this.#code = code;
+    this.#code = transformCode(code, "r");
     this.#mode = context.mode;
   }
 
diff --git a/src/snippets/perl/runner.pl b/src/snippets/perl/runner.pl
@@ -64,6 +64,21 @@ sub write_message {
     exit 1;
 }
 
+# ----------------------------------------------------------------
+# __get / __set helpers for {{}} template expansion
+# ----------------------------------------------------------------
+
+sub __get {
+    my ($r, $keyspec) = @_;
+    return RecsSDK::_resolve($r, $keyspec);
+}
+
+sub __set {
+    my ($r, $keyspec, $value) = @_;
+    RecsSDK::_set_path($r, $keyspec, $value);
+    return $value;
+}
+
 # ----------------------------------------------------------------
 # Compile snippet
 # ----------------------------------------------------------------
diff --git a/src/snippets/python/runner.py b/src/snippets/python/runner.py
@@ -116,6 +116,13 @@ def emit(rec_or_dict: Any) -> None:
                     f"emit() expects a Record or dict, got {type(rec_or_dict).__name__}"
                 )
 
+        def __get(rec: Record, ks: str) -> Any:
+            return rec.get("@" + ks)
+
+        def __set(rec: Record, ks: str, value: Any) -> Any:
+            rec.set("@" + ks, value)
+            return value
+
         # Build the snippet namespace
         namespace: dict[str, Any] = {
             "r": r,
@@ -124,6 +131,8 @@ def emit(rec_or_dict: Any) -> None:
             "filename": "NONE",
             "emit": emit,
             "Record": Record,
+            "__get": __get,
+            "__set": __set,
             # Expose builtins for convenience
             "json": __import__("json"),
             "re": __import__("re"),
diff --git a/tests/Executor.test.ts b/tests/Executor.test.ts
@@ -28,6 +28,118 @@ describe("Executor", () => {
       expect(result).toContain('"a"');
       expect(result).toContain('"b"');
     });
+
+    test("transforms {{key}} += value to compound assignment", () => {
+      const result = transformCode("{{x}} += 2");
+      expect(result).toBe('__set(r, "x", __get(r, "x") + 2)');
+    });
+
+    test("transforms {{key}} -= value to compound assignment", () => {
+      const result = transformCode("{{x}} -= 1");
+      expect(result).toBe('__set(r, "x", __get(r, "x") - 1)');
+    });
+
+    test("transforms {{key}} *= value to compound assignment", () => {
+      const result = transformCode("{{x}} *= 3");
+      expect(result).toBe('__set(r, "x", __get(r, "x") * 3)');
+    });
+
+    test("transforms {{key}} /= value to compound assignment", () => {
+      const result = transformCode("{{x}} /= 2");
+      expect(result).toBe('__set(r, "x", __get(r, "x") / 2)');
+    });
+
+    test("transforms {{key}} **= value to compound assignment", () => {
+      const result = transformCode("{{x}} **= 2");
+      expect(result).toBe('__set(r, "x", __get(r, "x") ** 2)');
+    });
+
+    test("transforms {{key}} ||= value to compound assignment", () => {
+      const result = transformCode("{{x}} ||= 5");
+      expect(result).toBe('__set(r, "x", __get(r, "x") || 5)');
+    });
+
+    test("transforms {{key}} &&= value to compound assignment", () => {
+      const result = transformCode("{{x}} &&= 5");
+      expect(result).toBe('__set(r, "x", __get(r, "x") && 5)');
+    });
+
+    test("transforms {{key}} ??= value to compound assignment", () => {
+      const result = transformCode("{{x}} ??= 5");
+      expect(result).toBe('__set(r, "x", __get(r, "x") ?? 5)');
+    });
+
+    test("transforms {{key}} >>= value to compound assignment", () => {
+      const result = transformCode("{{x}} >>= 1");
+      expect(result).toBe('__set(r, "x", __get(r, "x") >> 1)');
+    });
+
+    test("transforms {{key}} >>>= value to compound assignment", () => {
+      const result = transformCode("{{x}} >>>= 1");
+      expect(result).toBe('__set(r, "x", __get(r, "x") >>> 1)');
+    });
+
+    test("transforms {{key}} <<= value to compound assignment", () => {
+      const result = transformCode("{{x}} <<= 1");
+      expect(result).toBe('__set(r, "x", __get(r, "x") << 1)');
+    });
+
+    test("transforms {{key}} |= value to compound assignment", () => {
+      const result = transformCode("{{x}} |= 3");
+      expect(result).toBe('__set(r, "x", __get(r, "x") | 3)');
+    });
+
+    test("transforms {{key}} &= value to compound assignment", () => {
+      const result = transformCode("{{x}} &= 3");
+      expect(result).toBe('__set(r, "x", __get(r, "x") & 3)');
+    });
+
+    test("transforms {{key}} ^= value to compound assignment", () => {
+      const result = transformCode("{{x}} ^= 3");
+      expect(result).toBe('__set(r, "x", __get(r, "x") ^ 3)');
+    });
+
+    test("transforms {{key}} //= value to compound assignment", () => {
+      const result = transformCode("{{x}} //= 10");
+      expect(result).toBe('__set(r, "x", __get(r, "x") // 10)');
+    });
+
+    test("transforms {{key}} %= value to compound assignment", () => {
+      const result = transformCode("{{x}} %= 3");
+      expect(result).toBe('__set(r, "x", __get(r, "x") % 3)');
+    });
+
+    test("compound assignment with nested keyspec", () => {
+      const result = transformCode("{{a/b}} += 1");
+      expect(result).toBe('__set(r, "a/b", __get(r, "a/b") + 1)');
+    });
+
+    test("uses custom recordVar", () => {
+      const result = transformCode("{{x}} += 1", "$r");
+      expect(result).toBe('__set($r, "x", __get($r, "x") + 1)');
+    });
+
+    test("uses custom recordVar for simple assign", () => {
+      const result = transformCode("{{x}} = 5", "$r");
+      expect(result).toBe('__set($r, "x", 5)');
+    });
+
+    test("uses custom recordVar for read", () => {
+      const result = transformCode("{{x}}", "$r");
+      expect(result).toBe('__get($r, "x")');
+    });
+
+    test("does not match == as assignment", () => {
+      const result = transformCode("{{x}} == 5");
+      expect(result).not.toContain("__set");
+      expect(result).toContain("__get");
+    });
+
+    test("does not match === as assignment", () => {
+      const result = transformCode("{{x}} === 5");
+      expect(result).not.toContain("__set");
+      expect(result).toContain("__get");
+    });
   });
 
   describe("executeCode", () => {
@@ -62,6 +174,34 @@ describe("Executor", () => {
       expect(data["new_field"]).toBe("created");
     });
 
+    test("evaluates {{}} compound assignment +=", () => {
+      const executor = new Executor("{{x}} += 10");
+      const record = new Record({ x: 5 });
+      executor.executeCode(record);
+      expect(record.dataRef()["x"]).toBe(15);
+    });
+
+    test("evaluates {{}} compound assignment -=", () => {
+      const executor = new Executor("{{x}} -= 3");
+      const record = new Record({ x: 10 });
+      executor.executeCode(record);
+      expect(record.dataRef()["x"]).toBe(7);
+    });
+
+    test("evaluates {{}} compound assignment *=", () => {
+      const executor = new Executor("{{x}} *= 4");
+      const record = new Record({ x: 3 });
+      executor.executeCode(record);
+      expect(record.dataRef()["x"]).toBe(12);
+    });
+
+    test("evaluates {{}} compound assignment **=", () => {
+      const executor = new Executor("{{x}} **= 3");
+      const record = new Record({ x: 2 });
+      executor.executeCode(record);
+      expect(record.dataRef()["x"]).toBe(8);
+    });
+
     test("provides $line counter", () => {
       const executor = new Executor("return $line");
       const r = new Record({});
diff --git a/tests/snippets/TemplateExpansion.test.ts b/tests/snippets/TemplateExpansion.test.ts
