functionDefStatement :: Parser AST.Statement
functionDefStatement = ranged $ AST.DefinitionStatement
  <$> reserved "let"
  <*> functionPrototype <* Token.symbol "="
  <*> expression
functionDefStatement :: Parser AST.Statement
functionDefStatement = ranged $ AST.DefinitionStatement
  <$> reserved "let"
  <*> functionPrototype <* Token.symbol "="
  <*> expression
functionDefStatement = ranged $ AST.DefinitionStatement
  <$> reserved "let"
  <*> functionPrototype <* Token.symbol "="
  <*> expression