EKB This is a follow-up to the discussion on Is Tcl Different!.
Here's the wonderful HTML parser in 10 lines as posted on that page:
############################################
# Turn HTML into TCL commands
# html A string containing an html document
# cmd A command to run for each html tag found
# start The name of the dummy html start/stop tags
proc HMparse_html {html {cmd HMtest_parse} {start hmstart}} {
regsub -all \{ $html {\&ob;} html
regsub -all \} $html {\&cb;} html
set w " \t\r\n" ;# white space
proc HMcl x {return "\[$x\]"}
set exp <(/?)([HMcl ^$w>]+)[HMcl $w]*([HMcl ^>]*)>
set sub "\}\n$cmd {\\2} {\\1} {\\3} \{"
regsub -all $exp $html $sub html
eval "$cmd {$start} {} {} \{ $html \}"
eval "$cmd {$start} / {} {}"
}But it was missing the default value for cmd, HMtest_parse, so I wrote one and applied it to a sample bit of HTML:
proc HMtest_parse {tag state props body} {
if {$state == ""} {
set msg "Start $tag"
if {$props != ""} {
set msg "$msg with args: $props"
}
set msg "$msg\n$body"
} else {
set msg "End $tag"
}
puts $msg
}
HMparse_html {
<html>
<p class="bubba">
This is my very first paragraph. How do you
like it? I think it has a lot to recommend it.
</p>
<p class="louielouie">
This is my second paragraph, which is OK,
but not as nice as my first one.
</p>
</html>
}This gives the following output:
Start hmstart
Start html
Start p with args: class="bubba"
This is my very first paragraph. How do you
like it? I think it has a lot to recommend it.
End p
Start p with args: class="louielouie"
This is my second paragraph, which is OK,
but not as nice as my first one.
End p
End html
End hmstartIn fact, the code is not HTML-specific, and can handle simple XML code (e.g., that doesn't use the self-closing <tag/> format). It's like a mini-SAX.