Summary: Add Macros to track and explain Expressions

This PR introduces two new macros (@store_expr and @explain) and related infrastructure to address the following idea from the code camp (see #786):

Backend/user interace

• Show the expression that is being used to evaluate a certain field in dd

This PR provides a way to track the chained-executions of certain expressions, which can be helpful for debugging or understanding complex dynamically defined functions.

Dependency / Related PRs

This change depends on related PRs in IMAS and IMASdd packages to fully function.
Please refer to the following PR links in the related repositories:

• IMAS PR (Feature/explain expression IMAS.jl#224)
• IMASdd PR (Explain the expression when FLAG_EXPLAIN_EXPRESSION[]=true IMASdd.jl#47)

Key Changes

• Defines a new ExprInfo struct to store the name, arguments, and body of anonymous functions defined via dict["key"] = (args...) -> body assignments.
• Introduces @store_expr macro:
  • Automatically executes the given assignment.
  • Extracts argument and body information from the anonymous function.
  • Stores the resulting ExprInfo in expr_info_dict.
• Introduces @explain macro:
  • Temporarily enables IMASdd.FLAG_EXPLAIN_EXPRESSION.
  • Runs the provided expression under this flag to display additional explanatory information.
  • Resets the flag after execution.

Examples

1. Dynamic expressions

Suppose we want to execute the some dynamic expressions under dd.summary.volume_average as the following:

One can evaluate the expressions by typing it on the REPL, which will give the final result only.

# The following will give a single element Vector as the result
dd.summary.volume_average.n_e.value

However, to compute the final single value, the above expression actually executed multiple chained-expressions under the hood.

The new macro @explain explains these detailed procedures to evaluate the given dynamic expression. Note that it will also explain the chained expressions that are required to evalute the original expression.

# The following will explain the details of chained expressions
@explain dd.summary.volume_average.n_e.value; # add semicolon to omit the final result

2. Onetime expressions

One can use the same @explain macro to see the detailed procedure for the onetime expression as well.
Note that once the onetime expression is evaluated, it is no longer an expression and has a fixed value.
Hence, the subsequent call of @explain on the same onetime expression has nothing to explain.

# First execution will show the explanation
@explain dd.core_sources.source[2].profiles_1d[1].grid.area;

# Subsequent execution will show nothing, except the final result
@explain dd.core_sources.source[2].profiles_1d[1].grid.area;

Note

• CI might fail until dependent PRs are merged.
• Once the dependent changes are integrated, this PR should work as expected.