Insensitive case

Configuration

  • Introduce the icase option name
    • Which is made persistent through the MODULES_ICASE environment variable
    • Many people asked for separate options as applying an icase approach to a module loading context is not seen desired by everybody whereas it is in an module search context
    • Defined levels of enablement are:
      • never
      • search
      • always
    • icase option will be set by default to
      • never in v4 not to change existing behaviors
      • search in v5 as it seems to be a general improvement for everybody
    • A command-line switch --icase (short form -i) is added
      • Was there in Modules 3 (for search sub-command only)
      • When set, equals to an always icase mode
  • No immediate need for a --no-icase command-line switch
    • Combining configuration option and --icase command-line switch seems sufficient

Specification

  • When enabled, match query string in a case insensitive manner
    • query soFT returns soft, SOFT, soFT, SOft, sOft and so on
  • In case multiple files correspond to the same icase word
    • like soft, soFT, SoFt, SOFT filenames
    • query SOFT returns SOFT (exact match is returned among possibilities)
    • query SoFt returns SoFt (exact match is returned among possibilities)
    • query SOft returns soft (highest lexicographically sorted match is returned among possibilities)
    • query soFt returns soft (highest lexicographically sorted match is returned among possibilities)
  • When icase is enabled for search context it applies to
  • When icase is enabled for all context it applies to
    • search context like described above
    • module specification passed as argument in following contexts:
    • module alias and symbolic version resolution triggered by
      • module-info alias
      • module-info version
      • getPathToModule
      • isModuleEvaluated
    • the gathering of all module alias and symbolic version targeting a given module
      • this is processed by getAllModuleResolvedName procedure
      • which is called by
        • doesLoadingModuleMatchesName
        • cmdModuleLoad
  • Note that whatis specification passed as argument to the search sub-command is always matched in a case insensitive manner

Corner cases

  • When looking for the best match among loaded modules to select one module to unload, lastly loaded module, or firstly loaded module depending on unload_match_order configuration, will be returned
    • When insensitive case is enabled, last or first icase match will be returned even if an exact match is present among the loaded module list
    • This behavior has an impact in case multiple available modules correspond to the same insensitive case string
      • For instance iCaSe and IcAsE modules
  • When icase is enabled on all contexts and multiple directories match same icase module name
    • for instance following modules exist: ICASE/1.1, icase/1.2, iCaSe/1.3 and iCaSe/1.4
    • a module avail -i icase will sort iCaSe/1.4 as the highest entry
    • however a module load -i icase command will load icase/1.2
      • as icase directory matches query
    • and also module load -i ICase command will load icase/1.2
      • as no directory ICase exists, result is returned from highest directory: icase