# -*- shell-script -*-
# "Examine" debugger command.
#
#   Copyright (C) 2002-2004, 2006, 2008, 2011, 2016 Rocky Bernstein
#   <rocky@gnu.org>
#
#   This program is free software; you can redistribute it and/or
#   modify it under the terms of the GNU General Public License as
#   published by the Free Software Foundation; either version 2, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#   General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; see the file COPYING.  If not, write to
#   the Free Software Foundation, 59 Temple Place, Suite 330, Boston,
#   MA 02111 USA.

if [[ $0 == ${BASH_SOURCE[0]} ]]  {
    setglobal dirname = $(BASH_SOURCE[0]%/*)
    [[ $dirname == $0 ]] && setglobal top_dir = ''..'' || setglobal top_dir = "$(dirname)/.."
    for lib_file in [help alias]  { source $top_dir/lib/$(lib_file).sh; }
}

_Dbg_help_add 'examine' \
"**examine** *expr*

Print value of an expression via \"typeset\", \"let\", and failing these,
\"eval\".

To see the structure of a variable do not prepeand a leading $.

Arithmetic expressions also do not need leading $ for
their value is to be substituted.

However if *expr* falls into neither these, categories variables
witih *expr* need $ to have their value substituted.

Examples:
---------

   # code:
   # typeset -a typeset -a x=(2 3 4)
   # typeset -ir p=1
   bashdb<1> examine x   # note no $
   declare -a x='([0]="2" [1]="3" [2]="4")'
   bashdb<2> examine $x  # note with $
   1  # because this is how bash evaluates $x
   bashdb<3> x p
   declare -ir p="1"
   bashdb<3> x p+2
   3
   bashdb<3> x $p+2
   3

See also:
---------

**eval** and **pr**."

proc _Dbg_do_examine {
    typeset -r _Dbg_expr = $(@:-"$_Dbg_last_x_args")
    typeset _Dbg_result = ''
    typeset isblank = $_Dbg_expr
    if [[ -z $isblank ]]  {
	_Dbg_msg $_Dbg_expr
    } elif _Dbg_defined $_Dbg_expr  {
	setglobal _Dbg_result = $[typeset -p $_Dbg_expr]
	_Dbg_msg $_Dbg_result
    } elif _Dbg_is_function $_Dbg_expr $_Dbg_set_debug {
	setglobal _Dbg_result = $[typeset -f $_Dbg_expr]
	_Dbg_msg $_Dbg_result
    } else {
	typeset -i _Dbg_rc = ''
	eval let _Dbg_result=$_Dbg_expr !2 >/dev/null; setglobal _Dbg_rc = $Status
	if sh-expr ' _Dbg_rc != 0 '  {
	    _Dbg_do_print $_Dbg_expr
	} else {
	    _Dbg_msg $_Dbg_result
	}
    }
    setglobal _Dbg_last_x_args = $_Dbg_x_args
    return 0
}

_Dbg_alias_add 'x' 'examine'

# Demo it.
if [[ $0 == ${BASH_SOURCE[0]} ]]  {
    for _Dbg_file in [fns msg]  {
	source $top_dir/lib/$(_Dbg_file).sh
    }
    source $top_dir/command/help.sh
    setglobal _Dbg_args = ''examine''
    _Dbg_do_help x
    _Dbg_do_examine top_dir
}