diff options
Diffstat (limited to 'library/tm.tcl')
| -rw-r--r-- | library/tm.tcl | 214 |
1 files changed, 101 insertions, 113 deletions
diff --git a/library/tm.tcl b/library/tm.tcl index a2476ce..ca0bbf7 100644 --- a/library/tm.tcl +++ b/library/tm.tcl @@ -1,48 +1,44 @@ # -*- tcl -*- # -# Searching for Tcl Modules. Defines a procedure, declares it as the -# primary command for finding packages, however also uses the former -# 'package unknown' command as a fallback. +# Searching for Tcl Modules. Defines a procedure, declares it as the primary +# command for finding packages, however also uses the former 'package unknown' +# command as a fallback. # -# Locates all possible packages in a directory via a less restricted -# glob. The targeted directory is derived from the name of the -# requested package. I.e. the TM scan will look only at directories -# which can contain the requested package. It will register all -# packages it found in the directory so that future requests have a -# higher chance of being fulfilled by the ifneeded database without -# having to come to us again. +# Locates all possible packages in a directory via a less restricted glob. The +# targeted directory is derived from the name of the requested package, i.e. +# the TM scan will look only at directories which can contain the requested +# package. It will register all packages it found in the directory so that +# future requests have a higher chance of being fulfilled by the ifneeded +# database without having to come to us again. # -# We do not remember where we have been and simply rescan targeted -# directories when invoked again. The reasoning is this: +# We do not remember where we have been and simply rescan targeted directories +# when invoked again. The reasoning is this: # -# - The only way we get back to the same directory is if someone is -# trying to [package require] something that wasn't there on the -# first scan. +# - The only way we get back to the same directory is if someone is trying to +# [package require] something that wasn't there on the first scan. # # Either # 1) It is there now: If we rescan, you get it; if not you don't. # -# This covers the possibility that the application asked for a -# package late, and the package was actually added to the -# installation after the application was started. It shoukld -# still be able to find it. +# This covers the possibility that the application asked for a package +# late, and the package was actually added to the installation after the +# application was started. It shoukld still be able to find it. # -# 2) It still is not there: Either way, you don't get it, but the -# rescan takes time. This is however an error case and we dont't -# care that much about it +# 2) It still is not there: Either way, you don't get it, but the rescan +# takes time. This is however an error case and we dont't care that much +# about it # -# 3) It was there the first time; but for some reason a "package -# forget" has been run, and "package" doesn't know about it -# anymore. +# 3) It was there the first time; but for some reason a "package forget" has +# been run, and "package" doesn't know about it anymore. # -# This can be an indication that the application wishes to reload -# some functionality. And should work as well. +# This can be an indication that the application wishes to reload some +# functionality. And should work as well. # -# Note that this also strikes a balance between doing a glob targeting -# a single package, and thus most likely requiring multiple globs of -# the same directory when the application is asking for many packages, -# and trying to glob for _everything_ in all subdirectories when -# looking for a package, which comes with a heavy startup cost. +# Note that this also strikes a balance between doing a glob targeting a +# single package, and thus most likely requiring multiple globs of the same +# directory when the application is asking for many packages, and trying to +# glob for _everything_ in all subdirectories when looking for a package, +# which comes with a heavy startup cost. # # We scan for regular packages only if no satisfying module was found. @@ -71,35 +67,33 @@ namespace eval ::tcl::tm { # path with 'list'. # # Results -# No result for subcommands 'add' and 'remove'. A list of paths -# for 'list'. +# No result for subcommands 'add' and 'remove'. A list of paths for +# 'list'. # # Sideeffects -# The subcommands 'add' and 'remove' manipulate the list of -# paths to search for Tcl Modules. The subcommand 'list' has no -# sideeffects. +# The subcommands 'add' and 'remove' manipulate the list of paths to +# search for Tcl Modules. The subcommand 'list' has no sideeffects. proc ::tcl::tm::add {args} { # PART OF THE ::tcl::tm::path ENSEMBLE # # The path is added at the head to the list of module paths. # - # The command enforces the restriction that no path may be an - # ancestor directory of any other path on the list. If the new - # path violates this restriction an error wil be raised. + # The command enforces the restriction that no path may be an ancestor + # directory of any other path on the list. If the new path violates this + # restriction an error wil be raised. # - # If the path is already present as is no error will be raised and - # no action will be taken. + # If the path is already present as is no error will be raised and no + # action will be taken. variable paths - # We use a copy of the path as source during validation, and - # extend it as well. Because we not only have to detect if the new - # paths are bogus with respect to the existing paths, but also - # between themselves. Otherwise we can still add bogus paths, by - # specifying them in a single call. This makes the use of the new - # paths simpler as well, a trivial assignment of the collected - # paths to the official state var. + # We use a copy of the path as source during validation, and extend it as + # well. Because we not only have to detect if the new paths are bogus with + # respect to the existing paths, but also between themselves. Otherwise we + # can still add bogus paths, by specifying them in a single call. This + # makes the use of the new paths simpler as well, a trivial assignment of + # the collected paths to the official state var. set newpaths $paths foreach p $args { @@ -108,9 +102,8 @@ proc ::tcl::tm::add {args} { continue } - # Search for paths which are subdirectories of the new one. If - # there are any then the new path violates the restriction - # about ancestors. + # Search for paths which are subdirectories of the new one. If there + # are any then the new path violates the restriction about ancestors. set pos [lsearch -glob $newpaths ${p}/*] # Cannot use "in", we need the position for the message. @@ -119,10 +112,9 @@ proc ::tcl::tm::add {args} { "$p is ancestor of existing module path [lindex $newpaths $pos]." } - # Now look for existing paths which are ancestors of the new - # one. This reverse question forces us to loop over the - # existing paths, as each element is the pattern, not the new - # path :( + # Now look for existing paths which are ancestors of the new one. This + # reverse question forces us to loop over the existing paths, as each + # element is the pattern, not the new path :( foreach ep $newpaths { if {[string match ${ep}/* $p]} { @@ -134,10 +126,9 @@ proc ::tcl::tm::add {args} { set newpaths [linsert $newpaths 0 $p] } - # The validation of the input is complete and successful, and - # everything in newpaths is either an old path, or added. We can - # now extend the official list of paths, a simple assignment is - # sufficient. + # The validation of the input is complete and successful, and everything + # in newpaths is either an old path, or added. We can now extend the + # official list of paths, a simple assignment is sufficient. set paths $newpaths return @@ -146,8 +137,8 @@ proc ::tcl::tm::add {args} { proc ::tcl::tm::remove {args} { # PART OF THE ::tcl::tm::path ENSEMBLE # - # Removes the path from the list of module paths. The command is - # silently ignored if the path is not on the list. + # Removes the path from the list of module paths. The command is silently + # ignored if the path is not on the list. variable paths @@ -177,17 +168,16 @@ proc ::tcl::tm::list {} { # empty string. # exact - Either -exact or ommitted. # -# Name, version, and exact are used to determine -# satisfaction. The original is called iff no satisfaction was -# achieved. The name is also used to compute the directory to -# target in the search. +# Name, version, and exact are used to determine satisfaction. The +# original is called iff no satisfaction was achieved. The name is also +# used to compute the directory to target in the search. # # Results # None. # # Sideeffects -# May populate the package ifneeded database with additional -# provide scripts. +# May populate the package ifneeded database with additional provide +# scripts. proc ::tcl::tm::UnknownHandler {original name args} { # Import the list of paths to search for packages in module form. @@ -196,8 +186,8 @@ proc ::tcl::tm::UnknownHandler {original name args} { variable paths variable pkgpattern - # Without paths to search we can do nothing. (Except falling back - # to the regular search). + # Without paths to search we can do nothing. (Except falling back to the + # regular search). if {[llength $paths]} { set pkgpath [string map {:: /} $name] @@ -206,11 +196,10 @@ proc ::tcl::tm::UnknownHandler {original name args} { set pkgroot "" } - # We don't remember a copy of the paths while looping. Tcl - # Modules are unable to change the list while we are searching - # for them. This also simplifies the loop, as we cannot get - # additional directories while iterating over the list. A - # simple foreach is sufficient. + # We don't remember a copy of the paths while looping. Tcl Modules are + # unable to change the list while we are searching for them. This also + # simplifies the loop, as we cannot get additional directories while + # iterating over the list. A simple foreach is sufficient. set satisfied 0 foreach path $paths { @@ -223,12 +212,11 @@ proc ::tcl::tm::UnknownHandler {original name args} { } set strip [llength [file split $path]] - # We can't use glob in safe interps, so enclose the following - # in a catch statement, where we get the module files out - # of the subdirectories. In other words, Tcl Modules are - # not-functional in such an interpreter. This is the same - # as for the command "tclPkgUnknown", i.e. the search for - # regular packages. + # We can't use glob in safe interps, so enclose the following in a + # catch statement, where we get the module files out of the + # subdirectories. In other words, Tcl Modules are not-functional + # in such an interpreter. This is the same as for the command + # "tclPkgUnknown", i.e. the search for regular packages. catch { # We always look for _all_ possible modules in the current @@ -238,50 +226,50 @@ proc ::tcl::tm::UnknownHandler {original name args} { set pkgfilename [join [lrange [file split $file] $strip end] ::] if {![regexp -- $pkgpattern $pkgfilename --> pkgname pkgversion]} { - # Ignore everything not matching our pattern - # for package names. + # Ignore everything not matching our pattern for + # package names. continue } - if {[catch {package vcompare $pkgversion 0}]} { - # Ignore everything where the version part is - # not acceptable to "package vcompare". + try { + package vcompare $pkgversion 0 + } on error {} { + # Ignore everything where the version part is not + # acceptable to "package vcompare". continue } - # We have found a candidate, generate a "provide - # script" for it, and remember it. Note that we - # are using ::list to do this; locally [list] - # means something else without the namespace - # specifier. - - # NOTE. When making changes to the format of the - # provide command generated below CHECK that the - # 'LOCATE' procedure in core file - # 'platform/shell.tcl' still understands it, or, - # if not, update its implementation appropriately. + # We have found a candidate, generate a "provide script" + # for it, and remember it. Note that we are using ::list + # to do this; locally [list] means something else without + # the namespace specifier. + + # NOTE. When making changes to the format of the provide + # command generated below CHECK that the 'LOCATE' + # procedure in core file 'platform/shell.tcl' still + # understands it, or, if not, update its implementation + # appropriately. # - # Right now LOCATE's implementation assumes that - # the path of the package file is the last element - # in the list. + # Right now LOCATE's implementation assumes that the path + # of the package file is the last element in the list. package ifneeded $pkgname $pkgversion \ "[::list package provide $pkgname $pkgversion];[::list source -encoding utf-8 $file]" - # We abort in this unknown handler only if we got - # a satisfying candidate for the requested - # package. Otherwise we still have to fallback to - # the regular package search to complete the - # processing. + # We abort in this unknown handler only if we got a + # satisfying candidate for the requested package. + # Otherwise we still have to fallback to the regular + # package search to complete the processing. if { ($pkgname eq $name) && [package vsatisfies $pkgversion {*}$args] } then { set satisfied 1 - # We do not abort the loop, and keep adding - # provide scripts for every candidate in the - # directory, just remember to not fall back to - # the regular search anymore. + + # We do not abort the loop, and keep adding provide + # scripts for every candidate in the directory, just + # remember to not fall back to the regular search + # anymore. } } } @@ -292,8 +280,8 @@ proc ::tcl::tm::UnknownHandler {original name args} { } } - # Fallback to previous command, if existing. See comment above - # about ::list... + # Fallback to previous command, if existing. See comment above about + # ::list... if {[llength $original]} { uplevel 1 $original [::linsert $args 0 $name] @@ -374,7 +362,7 @@ proc ::tcl::tm::roots {paths} { return } -# Initialization. Set up the default paths, then insert the new -# handler into the chain. +# Initialization. Set up the default paths, then insert the new handler into +# the chain. if {![interp issafe]} { ::tcl::tm::Defaults } |