Adding New Keywords

To extend the Frost language with new keywords, you'll need to modify several components of the compiler. Here's a step-by-step guide using the provided code as a reference:

1. Update the Parser

In the Ast.Parser.Expr module, add a new parsing function for your keyword:

parseNewKeyword :: PU.Parser AT.Expr
parseNewKeyword = do
  srcLoc <- PU.parseSrcLoc
  _ <- PU.symbol "newkeyword"
  -- Add parsing logic for the new keyword
  -- For example:
  expr <- parseExpr
  return $ AT.NewKeyword srcLoc expr

Then, add this new parser to the parseTerm function:

parseTerm :: PU.Parser AT.Expr
parseTerm =
  M.choice
    [ -- ... existing choices ...
    , parseNewKeyword
    , parseParenExpr
    ]

2. Extend the AST

In the Ast.Types module, add a new constructor to the Expr data type:

data Expr
  = -- ... existing constructors ...
  | NewKeyword SrcLoc Expr

3. Implement Semantic Analysis

If your new keyword requires semantic analysis, update the relevant functions in the semantic analysis phase. This might involve modifying the type checker or other analysis passes.

4. Add Code Generation

Implement code generation for your new keyword in the appropriate module within Codegen.ExprGen:

-- | Generate LLVM IR for a new keyword expression.
generateNewKeyword :: AT.Expr -> AT.Expr -> Codegen AST.Operand
generateNewKeyword loc expr = do
  -- Generate LLVM IR for your new keyword
  -- For example:
  exprOp <- generateExpr expr
  -- Add LLVM instructions as needed
  return exprOp

5. Update Error Handling

In Codegen.Errors, add any new error types related to your keyword:

data CodegenErrorType
  = -- ... existing error types ...
  | InvalidNewKeywordUsage AT.Expr

6. Modify Utility Functions

Update utility functions like getLoc in Shared.Utils to handle your new expression type:

getLoc :: AT.Expr -> AT.SrcLoc
getLoc expr = case expr of
  -- ... existing cases ...
  AT.NewKeyword loc _ -> loc

7. Add Tests

Create new test cases in the test/ directory to ensure your keyword works as expected:

testNewKeyword :: Test
testNewKeyword = TestCase $ do
  let code = "newkeyword someExpression"
  result <- runParser parseExpr code
  assertEqual "New keyword parsing" expectedAST result

8. Update Documentation

Don't forget to update the language documentation to include information about your new keyword, its syntax, and usage examples.

By following these steps and integrating your changes with the existing codebase, you can successfully extend Frost with new keywords while maintaining its integrity and consistency.