Phase 2

[itsfuad]

This pull request includes significant changes to error handling, the lexer, and the parser, as well as updates to the language's type and struct definitions. The most important changes are summarized below:

Error Handling Enhancements:

• Introduced an ERROR_LEVEL type with different levels of error severity (ERROR_CRITICAL, ERROR_NORMAL, WARNING, INFO) and integrated it into the WalrusError struct. Critical errors now stop further execution and display a message indicating compilation has stopped. (errgen/errorPrinter.go, errgen/errorPrinter_test.go) [1] [2] [3] [4] [5] [6] [7] [8] [9]

Lexer Improvements:

• Added support for compound assignment operators (+=, -=, *=, /=, %=, ^=) in the lexer. (lexer/tokenizer.go)
• Updated error handling to use the new ERROR_CRITICAL level for unexpected characters. (lexer/tokenizer.go)

Parser Enhancements:

• Updated various parsing functions to use the new ERROR_CRITICAL level for error reporting, ensuring critical parsing errors halt further processing. (parser/expr.go, parser/functions.go) [1] [2] [3] [4] [5] [6]

Type and Struct Updates:

• Added new types and struct definitions, including Circle, Rectangle, and IShape interface with an implementation for Rectangle. Introduced type aliasing and tested type compatibility and method implementations. (language/types.wal)
• Updated StructLiteral to use a new StructProp type for properties, allowing for more detailed property definitions. (ast/expr.go)

Miscellaneous Changes:

• Modified PrintError function to improve the formatting of error messages, including color changes and additional information for critical errors. (errgen/errorPrinter.go) [1] [2] [3]
• Adjusted test cases to reflect changes in error handling and added new tests for hints and error levels. (errgen/errorPrinter_test.go)