Param struct as a AstNode
visit_param declaration
fix that now Param is not defined inside FuncDecl
Basic Pram::has_errors()
rename Param -> ParamDecl // walker now walks through ParamDecls
ParamDecl in astpr
initialized missing ini and fin attr to some AST nodes
flow control analyzer and tests
symbol table data structure
progress in type checker.. does not compile
refactored Type class
refactored implementation type
refactored Value -> Variable
implemented missing constructors