An extension for Tcl, written in C, that lets Tcl scripts access Tcl's own parser via the '''parse''' command.

As a package, the name is `parser`.

The tclparser source code is available from here:

http://tclpro.cvs.sourceforge.net/tclpro/tclparser/


** Building **

  cvs -d:pserver:anonymous@tclpro.cvs.sourceforge.net:/cvsroot/tclpro login
  cvs -z3 -d:pserver:anonymous@tclpro.cvs.sourceforge.net:/cvsroot/tclpro co tclparser
  mkdir tclparser/build
  cd tclparser/build
  ../configure --prefix=/home/tcl --with-tcl=/home/tcl/lib
  make
  make install

Despite CVS history showing no activity since 2007, this builds cleanly against 8.6.3.  That's a stable interface!

** Using **

As the http://tclpro.cvs.sourceforge.net/viewvc/tclpro/tclparser/doc/parse.man%|%manual%|% explains, it exposes one command `parse $type $text $range`, which returns a structure similar to [tcltest]'s [testparser], but a bit more convenient for script manipulation.  Like `tcltest::testparser`, this is a lightweight wrapper around http://www.tcl.tk/man/tcl/TclLib/ParseCmd.htm%|%functions in tclParse.c%|%.

A simple example to turn an [expr]ession into [namespace eval]able code:

======
package require parser 

proc expr2tcl {expr {parse ""}} {
    if {$parse eq ""} {
        set parse [parse expr $expr {0 end}]
    }
    lassign $parse type range parts
    lassign $range min max
    incr max $min
    incr max -1
    set text [string range $expr $min $max]
    set result ""
    switch $type {
        subexpr {
            set result [join [lmap part $parts {expr2tcl $expr $part}] " "]
            if {[lindex $parts 0 0] eq "operator"} {
                return \[$result\]
            } else {
                return $result
            }
        }
        default {
            return $text
        }
    }
}

# % puts [expr2tcl {sin($x)+4*$x-$x**(pow($x,2))}]
# [- [+ [sin $x] [* 4 $x]] [** $x [pow $x 2]]]
======

----
See also:
   * [parsetcl] (pure-Tcl alternative, different API)



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