README.md

Pablo's function expressions on the left side of the assignment

You can find Pablo's current (2024-11-07) implementation of function expressions on the left side of the assignment pablo-tfg branch of the ULL-ESIT-PL/babel-tanhauhau repo.

Important

Warning: This is work in progress. These comments can be outdated.

Here I am using the pabloparser and pablobabel links to compile the code:

➜  left-side git:(main) ls -l ../../node_modules/.bin/pablo*
lrwxr-xr-x@ 1 casianorodriguezleon  staff  128  7 nov 13:21 ../../node_modules/.bin/pablobabel -> /Users/casianorodriguezleon/campus-virtual/2324/learning/compiler-learning/babel-tanhauhau-pablo/packages/babel-cli/bin/babel.js
lrwxr-xr-x@ 1 casianorodriguezleon  staff  138  7 nov 13:20 ../../node_modules/.bin/pabloparser -> /Users/casianorodriguezleon/campus-virtual/2324/learning/compiler-learning/babel-tanhauhau-pablo/packages/babel-parser/bin/babel-parser.js
➜  left-side git:(main) 

Let us consider the following code:

➜ left-side git:(main) ✗ cat left-side-original.mjs

➜  left-side git:(main) ✗ cat left-side-original.mjs 
//foo.assign(10, 9) Alternative, defining assignable functions.
function @@ foo(bar) {
  return bar * 2;
}
foo(10) = 5;

console.log(foo(4));   // 8
console.log(foo(10));  // 5

When compiled with Pablo's parser we get an AST like:

➜  left-side git:(main) npx pabloparser left-side-original.mjs | jq '.program.body[0].assignable'
true

and:

➜ left-side git:(main) ✗ npx pabloparser left-side-original.mjs | jq '.program.body[1]'

{
  "type": "ExpressionStatement",
  "start": 107,
  "end": 119,
  "expression": {
    "type": "AssignmentExpression",
    "start": 107,
    "end": 118,
    "loc": {
      "start": {
        "line": 5,
        "column": 0
      },
      "end": {
        "line": 5,
        "column": 11
      }
    },
    "operator": "=",
    "left": {
      "type": "CallExpression",
      "start": 107,
      "end": 114,
      "loc": {
        "start": {
          "line": 5,
          "column": 0
        },
        "end": {
          "line": 5,
          "column": 7
        }
      },
      "callee": {
        "type": "Identifier",
        "start": 107,
        "end": 110,
        "loc": {
          "start": {
            "line": 5,
            "column": 0
          },
          "end": {
            "line": 5,
            "column": 3
          },
          "identifierName": "foo"
        },
        "name": "foo"
      },
      "arguments": [
        {
          "type": "NumericLiteral",
          "start": 111,
          "end": 113,
          "loc": {
            "start": {
              "line": 5,
              "column": 4
            },
            "end": {
              "line": 5,
              "column": 6
            }
          },
          "extra": {
            "rawValue": 10,
            "raw": "10"
          },
          "value": 10
        }
      ]
    },
    "right": {
      "type": "NumericLiteral",
      "start": 117,
      "end": 118,
      "loc": {
        "start": {
          "line": 5,
          "column": 10
        },
        "end": {
          "line": 5,
          "column": 11
        }
      },
      "extra": {
        "rawValue": 5,
        "raw": "5"
      },
      "value": 5
    }
  }
}

Using the configuration file:

➜ left-side git:(main) ✗ cat babel.config.json

{
  "plugins": [
    "../../babel-tanhauhau-pablo/packages/babel-parser/babel-left-side-plugin.cjs"
  ]
}

We can use now Pablo's version of babel transpiler for the input:

➜ left-side git:(main) ✗ npx pablobabel left-side-original.mjs

//foo.assign(10, 9) Alternative, defining assignable functions.
const foo = functionObject(function (bar) {
  return bar * 2;
});
assign(foo, 10, 5);
console.log(foo(4)); // 8

console.log(foo(10)); // 5