Using go fix to modernize Go code

This post introduces the rewritten go fix command in Go 1.26, which automatically modernizes Go codebases using a suite of analyzers.

• •Run `go fix ./...` to silently update source files, or use `-diff` flag to preview changes without applying them
• •Available analyzers include: any (interface{} → any), minmax (if/else → min/max), rangeint (3-clause for → range-over-int), stringscut (strings.Index → strings.Cut)
• •Go 1.26 introduces `new(expr)` syntax to initialize pointers with values, and the new `newexpr` fixer replaces helper functions like `newInt(x)` with direct `new(x)` calls
• •Synergistic fixes allow one modernization to unlock another (e.g., minmax → min after max is applied; stringsbuilder → fmt.Fprintf after Builder is introduced)
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