Add else if support

[antonmedv]

No description provided.

[Copilot]

Pull request overview

This PR adds support for else if chaining in conditional expressions, allowing multiple conditional branches without deep nesting. The implementation leverages recursive parsing to handle arbitrary chains of else if statements.

Key changes:

• Modified the parser to recognize and handle else if syntax by recursively calling parseConditionalIf() when "if" follows "else"
• Added test cases covering basic else if functionality, error handling, end-to-end execution, and AST printing

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
parser/parser.go	Added conditional logic to check for "if" token after "else" and recursively parse nested conditionals
parser/parser_test.go	Added test case for basic else if parsing and error test for malformed else followed by identifier
expr_test.go	Added end-to-end test verifying correct evaluation of else if expressions
ast/print_test.go	Added test verifying else if expressions print as nested ternary operators with proper parenthesization

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[Copilot]

Consider adding a test case for multiple chained else if statements to verify that the recursive implementation correctly handles chains longer than two conditionals. For example: if a { 1 } else if b { 2 } else if c { 3 } else { 4 } would test that the parser can handle arbitrarily long chains of conditionals.

[Copilot]

Consider adding a test case with multiple chained else if statements to ensure the feature works correctly for longer chains. For example: if 1 == 2 { "a" } else if 2 == 3 { "b" } else if 3 == 3 { "c" } else { "d" } with expected result "c".