Issue with Constant Declaration Merging in Go Script

[guiyomh]

Issue Description

I have encountered an issue while using the Go script for merging source files, particularly with the merging of constant declarations. The script combines constants into a single declaration, leading to initialization errors in the merged file.

Reproduction Steps

1. Define a custom type and constants as follows in separate files:

// File: types.go
tpackage main

type Category int

// File: constants.go
const (
	Ok Category = iota
	Lost
	Rescue
	Endangered
)

type Strategy int

const (
	NormalMode Strategy = iota
	RescueHuman
	RescueEndangered
)

2. Run the script to merge the source files.

Observed Behavior

The merged file shows errors in the constant declaration section, with some constants missing their initializations.

// File: _merged.go
package main

const (
	Endangered
	NormalMode	Strategy	= iota
	RescueHuman
	RescueEndangered
	Ok	Category	= iota
	Lost
	Rescue
)

type (
	Category	int
	Strategy	int
)

The issue seems to be related to the script combining constant declarations without maintaining their original structure and initializations. This can lead to incorrect behavior when using the merged file.

[mrsombre]

@guiyomh thanks for sharing. I have noticed this issue with iota constants for a while, btw I am not using this and use values in constants instead.
I'll take a look if I can manage to keep constants groups with iota notation and if that didn't break everything, I think I could fix it. Currently haven't much time, could be great, if you can propose pr.