Module selection contexts

Description of the different contexts where a module is expressed to get resolved to modulefiles.

Module identification to select one module

specification expresses exactly one module
must qualify version to select in case a module has multiple versions
expression may
- be absolute like mod/version
- be relative to the modulefile currently being evaluated like ./version or /version
- refer to symbolic version or module alias
specification used to resolve argument passed to the following commands:
- module-version
- module-alias
- module-virtual (cannot use symbolic version or module alias, should define an actual module)
- module-info symbols
- module-info version
- module-info loaded
relies on getModuleNameVersion procedure to get absolute name

specification expresses one or multiple modules
expression may
- be absolute like mod/version
- refer to implicit or explicitly defined default version like mod
- refer to extended default version like mod/1 (to refer to mod/1.1.1)
- refer to symbolic version or module alias
- specify multiple versions as list (mod@1,2) or range (mod@:1 or mod@1:2)
- refer to a variant specification (with or without a module name specification)
all modules matching specification are retrieved with getModules
specification used to resolve argument passed to the following commands:
- avail
- paths
- whatis
- list (matching specification retrieved from loaded modules, not getModules)
used to get all alias and symbolic version of loaded modules treated by:
- list
used to get all existing aliases and symbolic version (no module specification) by:
- aliases
used to get all existing modulefiles (no module specification) by:
- search

specification expresses one or multiple modules
relies on the module version specification to return all matching modules
then among matching modules, one is selected with getPathToModule:
- the one set has the default version (also called the explicit default version)
- or the highest version in case no explicit default is found among results (also called the implicit default version)
- nothing is returned in case no explicit default is found among matching modules and implicit default version mechanism is disabled
module selection may trigger another match retrieval
- for instance in case selection leads to an alias that resolves to a bare module name
specification used to resolve argument passed to the following commands:
- load
- unload (with attempt to match against loaded modules to resolve argument)
- switch
- help
- test
- display
- path
- is-avail
used to resolve aliases or symbolic versions treated by following commands:
- paths
- search

specification expresses one or multiple modules
expression may
- be absolute like mod/version
- refer to implicit or explicitly defined default version like mod
- refer to extended default version like mod/1 (to refer to mod/1.1.1)
- refer to symbolic version or module alias
- specify multiple versions as list (mod@1,2) or range (mod@:1 or mod@1:2)
version specification is matched against loaded or loading modules with variety of procedures:
- getLoadedMatchingName
- getLoadedWithClosestName
- isModuleEvaluated
specification used to resolve argument passed to the following commands:
- is-loaded
- info-loaded
- prereq
- conflict
for prereq command when version specification does not have a match among loaded or loading modules
- version specification is used to select one module per module specification
- for instance prereq mod@:1.8 mod@1.10 triggers load tentative of default version among mod@:1.8 then if this tentative fails load of mod@1.10 is attempted
- another example with prereq mod mod@1.10, which triggers load tentative of mod/default then if it fails load of mod@1.10 is attempted