diff --git a/src/runtime/javascript/ffi.ts b/src/runtime/javascript/ffi.ts
index 582cf9928..89df95197 100644
--- a/src/runtime/javascript/ffi.ts
+++ b/src/runtime/javascript/ffi.ts
@@ -236,12 +236,19 @@ const lint = ffi.Callback(PgfLiteral, [PgfUnmarshaller, ref.types.size_t, ref.re
 
 const lflt = ffi.Callback(PgfLiteral, [PgfUnmarshaller, ref.types.double],
   function (self, val: number): Pointer<Literal> {
-    return 0 as any
+    const obj = new Literal(val)
+    const buf = ref.alloc(ref.types.Object) as Pointer<Literal>
+    ref.writeObject(buf, 0, obj)
+    return buf
   })
 
 const lstr = ffi.Callback(PgfLiteral, [PgfUnmarshaller, PgfTextPtr],
   function (self, val: Pointer<any>): Pointer<Literal> {
-    return 0 as any
+    const jsval = PgfText_AsString(val)
+    const obj = new Literal(jsval)
+    const buf = ref.alloc(ref.types.Object) as Pointer<Literal>
+    ref.writeObject(buf, 0, obj)
+    return buf
   })
 
 const dtyp = ffi.Callback(PgfType, [PgfUnmarshaller, ref.types.int, PgfTypeHypoPtr, PgfTextPtr, ref.types.int, ref.refType(PgfExpr)],
@@ -249,8 +256,8 @@ const dtyp = ffi.Callback(PgfType, [PgfUnmarshaller, ref.types.int, PgfTypeHypoP
     return 0 as any
   })
 
-const free_ref = ffi.Callback(ref.types.void, [PgfUnmarshaller, ref.refType(ref.types.void)],
-  function (self, x: any): void {
+const free_ref = ffi.Callback(ref.types.void, [PgfUnmarshaller, ref.refType(ref.types.Object)],
+  function (self, x: Pointer<any>): void {
   })
 
 const un_vtbl = new PgfUnmarshallerVtbl({
diff --git a/src/runtime/javascript/tests/basic.test.ts b/src/runtime/javascript/tests/basic.test.ts
index 51c6433ba..3146146c3 100644
--- a/src/runtime/javascript/tests/basic.test.ts
+++ b/src/runtime/javascript/tests/basic.test.ts
@@ -209,7 +209,7 @@ describe('abstract syntax', () => {
 
 // ----------------------------------------------------------------------------
 
-describe('expressions', () => {
+describe.only('expressions', () => {
   test('small integer', () => {
     const e1 = PGF.readExpr('123')
     const e2 = new PGF.ExprLit(123)
@@ -253,4 +253,36 @@ describe('expressions', () => {
     expect(e1).toEqual(e2)
     expect(e1).not.toEqual(e3)
   })
+
+  test('float', () => {
+    const e1 = PGF.readExpr('3.142')
+    const e2 = new PGF.ExprLit(3.142)
+    const e3 = new PGF.ExprLit(2.014)
+    expect(e1).toEqual(e2)
+    expect(e1).not.toEqual(e3)
+  })
+
+  test('negative float', () => {
+    const e1 = PGF.readExpr('-3.142')
+    const e2 = new PGF.ExprLit(-3.142)
+    const e3 = new PGF.ExprLit(-2.014)
+    expect(e1).toEqual(e2)
+    expect(e1).not.toEqual(e3)
+  })
+
+  test('string', () => {
+    const e1 = PGF.readExpr('"abc"')
+    const e2 = new PGF.ExprLit('abc')
+    const e3 = new PGF.ExprLit('def')
+    expect(e1).toEqual(e2)
+    expect(e1).not.toEqual(e3)
+  })
+
+  test('string unicode', () => {
+    const e1 = PGF.readExpr('"açġħ"')
+    const e2 = new PGF.ExprLit('açġħ')
+    const e3 = new PGF.ExprLit('acgh')
+    expect(e1).toEqual(e2)
+    expect(e1).not.toEqual(e3)
+  })
 })