Fix: Support expressions as array indices in ArcaneScript

[thecloudcode]

Summary

This PR enhances the array access functionality in ArcaneScript by supporting expressions (including variables) as array indices instead of limiting it to numeric literals.

Fixes #1

Changes Made

1. Grammar Update: Modified ArcaneGrammar7.grm to replace NumberLiteral with <Expression> in array access rules.

   • Updated rule: <Value> ::= Identifier '[' <Expression> ']'
   • Updated rule: <Statement> ::= Identifier '=' Identifier '[' <Expression> ']' ';'

2. Code Modifications:

   • ArrayAccess.java: Updated to process and evaluate expressions as indices, including type checking and error handling for invalid index types and out-of-bounds access.
   • ArrayValue.java: Introduced a new class to handle array access when used as a value, ensuring consistency in behavior.

Testing and Validation

• Tested with array access scenarios involving numeric literals and variable-based indices.
• Verified behavior with both value retrieval (e.g., println x[i]) and assignment scenarios (a = x[i]).
• Rebuilt and deployed the ArcaneInterpreter and ArcaneHttpServer to ensure changes are correctly integrated.

Notes

• Ensure all related grammar rules dealing with array access are updated to use <Expression> instead of NumberLiteral.
• Example tested:

  array x[2] = {0, 1}; 
  for (i = 0; i < 2; i = i + 1;) { 
      println x[i]; 
  }

  This works as expected with both variable and literal indices.

Let me know if there are any questions or additional updates required!