v0.4.0-rc4

Breaking changes

• Move reader/parse to internal/parse

Maintenance

• Upgrade dependency golang.org/x/exp
• Upgrade CI Docker image Alpine from 3.16 to 3.18
• Upgrade Go from 1.20 to 1.21
• Upgrade actions/checkout from 3 to 4 (#12)

Features

• reader:
  • add builtin methods: Int8, Int16, Int32, Int64, Int8Ptr, Int16Ptr, Int32Ptr, Int64Ptr, Float32, Float32Ptr and Float64Ptr
  • default reader sources are flags then env isntead of only env

Documentation

• Simplify README.md reader Go code example
• Update reader example code to use flag and env instead of both sources as env