# -*- 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]} ]]  {
    global dirname := $(BASH_SOURCE[0]%/*)
    [[ $dirname == $0 ]] && global top_dir := ''..'' || global top_dir := "$(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  {
	global _Dbg_result := $[typeset -p $_Dbg_expr]
	_Dbg_msg $_Dbg_result
    } elif _Dbg_is_function $_Dbg_expr $_Dbg_set_debug {
	global _Dbg_result := $[typeset -f $_Dbg_expr]
	_Dbg_msg $_Dbg_result
    } else {
	typeset -i _Dbg_rc
	eval let _Dbg_result=$_Dbg_expr !2 >/dev/null; global _Dbg_rc := $Status
	if (( _Dbg_rc != 0 ))  {
	    _Dbg_do_print $_Dbg_expr
	} else {
	    _Dbg_msg $_Dbg_result
	}
    }
    global _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 $top_dir/command/help.sh
    global _Dbg_args := ''examine''
    _Dbg_do_help x
    _Dbg_do_examine top_dir
}
(CommandList
  children: [
    (If
      arms: [
        (if_arm
          cond: [
            (Sentence
              child: 
                (DBracket
                  expr: 
                    (BoolBinary
                      op_id: BoolBinary_GlobDEqual
                      left: {($ VSub_Number "$0")}
                      right: 
                        {
                          (BracedVarSub
                            token: <VSub_Name BASH_SOURCE>
                            bracket_op: (ArrayIndex expr:(ArithWord w:{(Lit_Digits 0)}))
                            spids: [69 74]
                          )
                        }
                    )
                )
              terminator: <Op_Semi ";">
            )
          ]
          action: [
            (Assignment
              keyword: Assign_None
              pairs: [
                (assign_pair
                  lhs: (LhsName name:dirname)
                  op: Equal
                  rhs: 
                    {
                      (BracedVarSub
                        token: <VSub_Name BASH_SOURCE>
                        bracket_op: (ArrayIndex expr:(ArithWord w:{(Lit_Digits 0)}))
                        suffix_op: (StringUnary op_id:VOp1_Percent arg_word:{(Lit_Slash /) ("*")})
                        spids: [84 92]
                      )
                    }
                  spids: [83]
                )
              ]
              spids: [83]
            )
            (AndOr
              children: [
                (DBracket
                  expr: 
                    (BoolBinary
                      op_id: BoolBinary_GlobDEqual
                      left: {($ VSub_Name "$dirname")}
                      right: {($ VSub_Number "$0")}
                    )
                )
                (AndOr
                  children: [
                    (Assignment
                      keyword: Assign_None
                      pairs: [
                        (assign_pair
                          lhs: (LhsName name:top_dir)
                          op: Equal
                          rhs: {(SQ <..>)}
                          spids: [107]
                        )
                      ]
                      spids: [107]
                    )
                    (Assignment
                      keyword: Assign_None
                      pairs: [
                        (assign_pair
                          lhs: (LhsName name:top_dir)
                          op: Equal
                          rhs: {(${ VSub_Name dirname) (/..)}
                          spids: [114]
                        )
                      ]
                      spids: [114]
                    )
                  ]
                  op_id: Op_DPipe
                )
              ]
              op_id: Op_DAmp
            )
            (ForEach
              iter_name: lib_file
              iter_words: [{(help)} {(alias)}]
              do_arg_iter: False
              body: 
                (DoGroup
                  children: [
                    (Sentence
                      child: 
                        (C {(source)} {($ VSub_Name "$top_dir") (/lib/) (${ VSub_Name lib_file) (.sh)})
                      terminator: <Op_Semi ";">
                    )
                  ]
                  spids: [133 145]
                )
              spids: [126 131]
            )
          ]
          spids: [-1 80]
        )
      ]
      spids: [-1 147]
    )
    (C {(_Dbg_help_add)} {(SQ <examine>)} 
      {
        (DQ ("**examine** *expr*\n") ("\n") ("Print value of an expression via ") 
          (EscapedLiteralPart token:<Lit_EscapedChar "\\\"">) (typeset) (EscapedLiteralPart token:<Lit_EscapedChar "\\\"">) (", ") 
          (EscapedLiteralPart token:<Lit_EscapedChar "\\\"">) (let) (EscapedLiteralPart token:<Lit_EscapedChar "\\\"">) (", and failing these,\n") 
          (EscapedLiteralPart token:<Lit_EscapedChar "\\\"">) (eval) (EscapedLiteralPart token:<Lit_EscapedChar "\\\"">) (".\n") ("\n") 
          ("To see the structure of a variable do not prepeand a leading ") (Lit_Other "$") (".\n") ("\n") ("Arithmetic expressions also do not need leading ") (Lit_Other "$") 
          (" for\n") ("their value is to be substituted.\n") ("\n") 
          ("However if *expr* falls into neither these, categories variables\n") ("witih *expr* need ") (Lit_Other "$") (" to have their value substituted.\n") ("\n") ("Examples:\n") 
          ("---------\n") ("\n") ("   # code:\n") ("   # typeset -a typeset -a x=(2 3 4)\n") ("   # typeset -ir p=1\n") 
          ("   bashdb<1> examine x   # note no ") (Lit_Other "$") ("\n") ("   declare -a x='([0]=")
        ) (2) (DQ (" [1]=")) (3) (DQ (" [2]=")) (4) 
        (DQ (")'\n") ("   bashdb<2> examine ") ($ VSub_Name "$x") ("  # note with ") (Lit_Other "$") 
          ("\n") ("   1  # because this is how bash evaluates ") ($ VSub_Name "$x") ("\n") ("   bashdb<3> x p\n") 
          ("   declare -ir p=")
        ) (1) 
        (DQ ("\n") ("   bashdb<3> x p+2\n") ("   3\n") ("   bashdb<3> x ") ($ VSub_Name "$p") ("+2\n") 
          ("   3\n") ("\n") ("See also:\n") ("---------\n") ("\n") ("**eval** and **pr**.")
        )
      }
    )
    (FuncDef
      name: _Dbg_do_examine
      body: 
        (BraceGroup
          children: [
            (C {(typeset)} {(-r)} 
              {(Lit_VarLike "_Dbg_expr=") 
                (BracedVarSub
                  token: <VSub_At "@">
                  suffix_op: 
                    (StringUnary
                      op_id: VTest_ColonHyphen
                      arg_word: {(DQ ($ VSub_Name "$_Dbg_last_x_args"))}
                    )
                  spids: [250 256]
                )
              }
            )
            (C {(typeset)} {(_Dbg_result)})
            (C {(typeset)} {(Lit_VarLike "isblank=") ($ VSub_Name "$_Dbg_expr")})
            (If
              arms: [
                (if_arm
                  cond: [
                    (Sentence
                      child: 
                        (DBracket
                          expr: (BoolUnary op_id:BoolUnary_z child:{($ VSub_Name "$isblank")})
                        )
                      terminator: <Op_Semi ";">
                    )
                  ]
                  action: [(C {(_Dbg_msg)} {(DQ ($ VSub_Name "$_Dbg_expr"))})]
                  spids: [-1 282]
                )
                (if_arm
                  cond: [
                    (Sentence
                      child: (C {(_Dbg_defined)} {($ VSub_Name "$_Dbg_expr")})
                      terminator: <Op_Semi ";">
                    )
                  ]
                  action: [
                    (Assignment
                      keyword: Assign_None
                      pairs: [
                        (assign_pair
                          lhs: (LhsName name:_Dbg_result)
                          op: Equal
                          rhs: 
                            {
                              (CommandSubPart
                                command_list: 
                                  (CommandList
                                    children: [(C {(typeset)} {(-p)} {($ VSub_Name "$_Dbg_expr")})]
                                  )
                                left_token: <Left_CommandSub "$(">
                                spids: [304 310]
                              )
                            }
                          spids: [303]
                        )
                      ]
                      spids: [303]
                    )
                    (C {(_Dbg_msg)} {(DQ ($ VSub_Name "$_Dbg_result"))})
                  ]
                  spids: [292 300]
                )
                (if_arm
                  cond: [
                    (Sentence
                      child: 
                        (C {(_Dbg_is_function)} {(DQ ($ VSub_Name "$_Dbg_expr"))} 
                          {($ VSub_Name "$_Dbg_set_debug")}
                        )
                      terminator: <Op_Semi ";">
                    )
                  ]
                  action: [
                    (Assignment
                      keyword: Assign_None
                      pairs: [
                        (assign_pair
                          lhs: (LhsName name:_Dbg_result)
                          op: Equal
                          rhs: 
                            {
                              (CommandSubPart
                                command_list: 
                                  (CommandList
                                    children: [(C {(typeset)} {(-f)} {($ VSub_Name "$_Dbg_expr")})]
                                  )
                                left_token: <Left_CommandSub "$(">
                                spids: [335 341]
                              )
                            }
                          spids: [334]
                        )
                      ]
                      spids: [334]
                    )
                    (C {(_Dbg_msg)} {(DQ ($ VSub_Name "$_Dbg_result"))})
                  ]
                  spids: [320 331]
                )
              ]
              else_action: [
                (C {(typeset)} {(-i)} {(_Dbg_rc)})
                (Sentence
                  child: 
                    (SimpleCommand
                      words: [{(eval)} {(let)} {(Lit_VarLike "_Dbg_result=") ($ VSub_Name "$_Dbg_expr")}]
                      redirects: [(Redir op_id:Redir_Great fd:2 arg_word:{(/dev/null)} spids:[368])]
                    )
                  terminator: <Op_Semi ";">
                )
                (Assignment
                  keyword: Assign_None
                  pairs: [
                    (assign_pair
                      lhs: (LhsName name:_Dbg_rc)
                      op: Equal
                      rhs: {($ VSub_QMark "$?")}
                      spids: [372]
                    )
                  ]
                  spids: [372]
                )
                (If
                  arms: [
                    (if_arm
                      cond: [
                        (Sentence
                          child: 
                            (DParen
                              child: 
                                (ArithBinary
                                  op_id: Arith_NEqual
                                  left: (ArithVarRef name:_Dbg_rc)
                                  right: (ArithWord w:{(Lit_Digits 0)})
                                )
                            )
                          terminator: <Op_Semi ";">
                        )
                      ]
                      action: [(C {(_Dbg_do_print)} {(DQ ($ VSub_Name "$_Dbg_expr"))})]
                      spids: [-1 391]
                    )
                  ]
                  else_action: [(C {(_Dbg_msg)} {(DQ ($ VSub_Name "$_Dbg_result"))})]
                  spids: [401 411]
                )
              ]
              spids: [351 414]
            )
            (Assignment
              keyword: Assign_None
              pairs: [
                (assign_pair
                  lhs: (LhsName name:_Dbg_last_x_args)
                  op: Equal
                  rhs: {(DQ ($ VSub_Name "$_Dbg_x_args"))}
                  spids: [417]
                )
              ]
              spids: [417]
            )
            (ControlFlow token:<ControlFlow_Return return> arg_word:{(0)})
          ]
          spids: [242]
        )
      spids: [238 241]
    )
    (C {(_Dbg_alias_add)} {(SQ <x>)} {(SQ <examine>)})
    (If
      arms: [
        (if_arm
          cond: [
            (Sentence
              child: 
                (DBracket
                  expr: 
                    (BoolBinary
                      op_id: BoolBinary_GlobDEqual
                      left: {($ VSub_Number "$0")}
                      right: 
                        {
                          (BracedVarSub
                            token: <VSub_Name BASH_SOURCE>
                            bracket_op: (ArrayIndex expr:(ArithWord w:{(Lit_Digits 0)}))
                            spids: [452 457]
                          )
                        }
                    )
                )
              terminator: <Op_Semi ";">
            )
          ]
          action: [
            (ForEach
              iter_name: _Dbg_file
              iter_words: [{(fns)} {(msg)}]
              do_arg_iter: False
              body: 
                (DoGroup
                  children: [
                    (C {(source)} {($ VSub_Name "$top_dir") (/lib/) (${ VSub_Name _Dbg_file) (.sh)})
                  ]
                  spids: [478 491]
                )
              spids: [471 476]
            )
            (C {(source)} {($ VSub_Name "$top_dir") (/command/help.sh)})
            (Assignment
              keyword: Assign_None
              pairs: [
                (assign_pair
                  lhs: (LhsName name:_Dbg_args)
                  op: Equal
                  rhs: {(SQ <examine>)}
                  spids: [500]
                )
              ]
              spids: [500]
            )
            (C {(_Dbg_do_help)} {(x)})
            (C {(_Dbg_do_examine)} {(top_dir)})
          ]
          spids: [-1 463]
        )
      ]
      spids: [-1 515]
    )
  ]
)