# Copyright (c) 2013 Peter Zotov  <whitequark@whitequark.org>
#
# Parts of the source are derived from ruby_parser:
# Copyright (c) Ryan Davis, seattle.rb
#
# MIT License
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

class Parser::Ruby20

token kCLASS kMODULE kDEF kUNDEF kBEGIN kRESCUE kENSURE kEND kIF kUNLESS
      kTHEN kELSIF kELSE kCASE kWHEN kWHILE kUNTIL kFOR kBREAK kNEXT
      kREDO kRETRY kIN kDO kDO_COND kDO_BLOCK kDO_LAMBDA kRETURN kYIELD kSUPER
      kSELF kNIL kTRUE kFALSE kAND kOR kNOT kIF_MOD kUNLESS_MOD kWHILE_MOD
      kUNTIL_MOD kRESCUE_MOD kALIAS kDEFINED klBEGIN klEND k__LINE__
      k__FILE__ k__ENCODING__ tIDENTIFIER tFID tGVAR tIVAR tCONSTANT
      tLABEL tCVAR tNTH_REF tBACK_REF tSTRING_CONTENT tINTEGER tFLOAT
      tREGEXP_END tUPLUS tUMINUS tUMINUS_NUM tPOW tCMP tEQ tEQQ tNEQ
      tGEQ tLEQ tANDOP tOROP tMATCH tNMATCH tDOT tDOT2 tDOT3 tAREF
      tASET tLSHFT tRSHFT tCOLON2 tCOLON3 tOP_ASGN tASSOC tLPAREN
      tLPAREN2 tRPAREN tLPAREN_ARG tLBRACK tLBRACK2 tRBRACK tLBRACE
      tLBRACE_ARG tSTAR tSTAR2 tAMPER tAMPER2 tTILDE tPERCENT tDIVIDE
      tDSTAR tPLUS tMINUS tLT tGT tPIPE tBANG tCARET tLCURLY tRCURLY
      tBACK_REF2 tSYMBEG tSTRING_BEG tXSTRING_BEG tREGEXP_BEG tREGEXP_OPT
      tWORDS_BEG tQWORDS_BEG tSYMBOLS_BEG tQSYMBOLS_BEG tSTRING_DBEG
      tSTRING_DVAR tSTRING_END tSTRING_DEND tSTRING tSYMBOL
      tNL tEH tCOLON tCOMMA tSPACE tSEMI tLAMBDA tLAMBEG tCHARACTER

prechigh
  right    tBANG tTILDE tUPLUS
  right    tPOW
  right    tUMINUS_NUM tUMINUS
  left     tSTAR2 tDIVIDE tPERCENT
  left     tPLUS tMINUS
  left     tLSHFT tRSHFT
  left     tAMPER2
  left     tPIPE tCARET
  left     tGT tGEQ tLT tLEQ
  nonassoc tCMP tEQ tEQQ tNEQ tMATCH tNMATCH
  left     tANDOP
  left     tOROP
  nonassoc tDOT2 tDOT3
  right    tEH tCOLON
  left     kRESCUE_MOD
  right    tEQL tOP_ASGN
  nonassoc kDEFINED
  right    kNOT
  left     kOR kAND
  nonassoc kIF_MOD kUNLESS_MOD kWHILE_MOD kUNTIL_MOD
  nonassoc tLBRACE_ARG
  nonassoc tLOWEST
preclow

rule

         program: top_compstmt

    top_compstmt: top_stmts opt_terms
                    {
                      result = @builder.compstmt(val[0])
                    }

       top_stmts: # nothing
                    {
                      result = []
                    }
                | top_stmt
                    {
                      result = [ val[0] ]
                    }
                | top_stmts terms top_stmt
                    {
                      result = val[0] << val[2]
                    }
                | error top_stmt
                    {
                      result = [ val[1] ]
                    }

        top_stmt: stmt
                | klBEGIN tLCURLY top_compstmt tRCURLY
                    {
                      result = @builder.preexe(val[0], val[1], val[2], val[3])
                    }

        bodystmt: compstmt opt_rescue opt_else opt_ensure
                    {
                      rescue_bodies     = val[1]
                      else_t,   else_   = val[2]
                      ensure_t, ensure_ = val[3]

                      if rescue_bodies.empty? && !else_.nil?
                        diagnostic :warning, :useless_else, nil, else_t
                      end

                      result = @builder.begin_body(val[0],
                                  rescue_bodies,
                                  else_t,   else_,
                                  ensure_t, ensure_)
                    }

        compstmt: stmts opt_terms
                    {
                      result = @builder.compstmt(val[0])
                    }

           stmts: # nothing
                    {
                      result = []
                    }
                | stmt_or_begin
                    {
                      result = [ val[0] ]
                    }
                | stmts terms stmt_or_begin
                    {
                      result = val[0] << val[2]
                    }
                | error stmt
                    {
                      result = [ val[1] ]
                    }

   stmt_or_begin: stmt
                | klBEGIN tLCURLY top_compstmt tRCURLY
                    {
                      if in_def?
                        diagnostic :error, :begin_in_method, nil, val[0]
                      end

                      result = @builder.preexe(val[0], val[1], val[2], val[3])
                    }

            stmt: kALIAS fitem
                    {
                      @lexer.state = :expr_fname
                    }
                    fitem
                    {
                      result = @builder.alias(val[0], val[1], val[3])
                    }
                | kALIAS tGVAR tGVAR
                    {
                      result = @builder.alias(val[0],
                                  @builder.gvar(val[1]),
                                  @builder.gvar(val[2]))
                    }
                | kALIAS tGVAR tBACK_REF
                    {
                      result = @builder.alias(val[0],
                                  @builder.gvar(val[1]),
                                  @builder.back_ref(val[2]))
                    }
                | kALIAS tGVAR tNTH_REF
                    {
                      diagnostic :error, :nth_ref_alias, nil, val[2]
                    }
                | kUNDEF undef_list
                    {
                      result = @builder.undef_method(val[0], val[1])
                    }
                | stmt kIF_MOD expr_value
                    {
                      result = @builder.condition_mod(val[0], nil,
                                                      val[1], val[2])
                    }
                | stmt kUNLESS_MOD expr_value
                    {
                      result = @builder.condition_mod(nil, val[0],
                                                      val[1], val[2])
                    }
                | stmt kWHILE_MOD expr_value
                    {
                      result = @builder.loop_mod(:while, val[0], val[1], val[2])
                    }
                | stmt kUNTIL_MOD expr_value
                    {
                      result = @builder.loop_mod(:until, val[0], val[1], val[2])
                    }
                | stmt kRESCUE_MOD stmt
                    {
                      rescue_body = @builder.rescue_body(val[1],
                                        nil, nil, nil,
                                        nil, val[2])

                      result = @builder.begin_body(val[0], [ rescue_body ])
                    }
                | klEND tLCURLY compstmt tRCURLY
                    {
                      result = @builder.postexe(val[0], val[1], val[2], val[3])
                    }
                | command_asgn
                | mlhs tEQL command_call
                    {
                      result = @builder.multi_assign(val[0], val[1], val[2])
                    }
                | var_lhs tOP_ASGN command_call
                    {
                      result = @builder.op_assign(val[0], val[1], val[2])
                    }
                | primary_value tLBRACK2 opt_call_args rbracket tOP_ASGN command_call
                    {
                      result = @builder.op_assign(
                                  @builder.index(
                                    val[0], val[1], val[2], val[3]),
                                  val[4], val[5])
                    }
                | primary_value tDOT tIDENTIFIER tOP_ASGN command_call
                    {
                      result = @builder.op_assign(
                                  @builder.call_method(
                                    val[0], val[1], val[2]),
                                  val[3], val[4])
                    }
                | primary_value tDOT tCONSTANT tOP_ASGN command_call
                    {
                      result = @builder.op_assign(
                                  @builder.call_method(
                                    val[0], val[1], val[2]),
                                  val[3], val[4])
                    }
                | primary_value tCOLON2 tCONSTANT tOP_ASGN command_call
                    {
                      result = @builder.op_assign(
                                  @builder.call_method(
                                    val[0], val[1], val[2]),
                                  val[3], val[4])
                    }
                | primary_value tCOLON2 tIDENTIFIER tOP_ASGN command_call
                    {
                      result = @builder.op_assign(
                                  @builder.call_method(
                                    val[0], val[1], val[2]),
                                  val[3], val[4])
                    }
                | backref tOP_ASGN command_call
                    {
                      @builder.op_assign(val[0], val[1], val[2])
                    }
                | lhs tEQL mrhs
                    {
                      result = @builder.assign(val[0], val[1],
                                  @builder.array(nil, val[2], nil))
                    }
                | mlhs tEQL arg_value
                    {
                      result = @builder.multi_assign(val[0], val[1], val[2])
                    }
                | mlhs tEQL mrhs
                    {
                      result = @builder.multi_assign(val[0], val[1],
                                  @builder.array(nil, val[2], nil))
                    }
                | expr

    command_asgn: lhs tEQL command_call
                    {
                      result = @builder.assign(val[0], val[1], val[2])
                    }
                | lhs tEQL command_asgn
                    {
                      result = @builder.assign(val[0], val[1], val[2])
                    }

            expr: command_call
                | expr kAND expr
                    {
                      result = @builder.logical_op(:and, val[0], val[1], val[2])
                    }
                | expr kOR expr
                    {
                      result = @builder.logical_op(:or, val[0], val[1], val[2])
                    }
                | kNOT opt_nl expr
                    {
                      result = @builder.not_op(val[0], nil, val[2], nil)
                    }
                | tBANG command_call
                    {
                      result = @builder.not_op(val[0], nil, val[1], nil)
                    }
                | arg

      expr_value: expr

    command_call: command
                | block_command

   block_command: block_call
                | block_call dot_or_colon operation2 command_args
                    {
                      result = @builder.call_method(val[0], val[1], val[2],
                                  nil, val[3], nil)
                    }

 cmd_brace_block: tLBRACE_ARG
                    {
                      @static_env.extend_dynamic
                    }
                    opt_block_param compstmt tRCURLY
                    {
                      result = [ val[0], val[2], val[3], val[4] ]

                      @static_env.unextend
                    }

           fcall: operation

         command: fcall command_args =tLOWEST
                    {
                      result = @builder.call_method(nil, nil, val[0],
                                  nil, val[1], nil)
                    }
                | fcall command_args cmd_brace_block
                    {
                      method_call = @builder.call_method(nil, nil, val[0],
                                        nil, val[1], nil)

                      begin_t, args, body, end_t = val[2]
                      result      = @builder.block(method_call,
                                      begin_t, args, body, end_t)
                    }
                | primary_value tDOT operation2 command_args =tLOWEST
                    {
                      result = @builder.call_method(val[0], val[1], val[2],
                                  nil, val[3], nil)
                    }
                | primary_value tDOT operation2 command_args cmd_brace_block
                    {
                      method_call = @builder.call_method(val[0], val[1], val[2],
                                        nil, val[3], nil)

                      begin_t, args, body, end_t = val[4]
                      result      = @builder.block(method_call,
                                      begin_t, args, body, end_t)
                    }
                | primary_value tCOLON2 operation2 command_args =tLOWEST
                    {
                      result = @builder.call_method(val[0], val[1], val[2],
                                  nil, val[3], nil)
                    }
                | primary_value tCOLON2 operation2 command_args cmd_brace_block
                    {
                      method_call = @builder.call_method(val[0], val[1], val[2],
                                        nil, val[3], nil)

                      begin_t, args, body, end_t = val[4]
                      result      = @builder.block(method_call,
                                      begin_t, args, body, end_t)
                    }
                | kSUPER command_args
                    {
                      result = @builder.keyword_cmd(:super, val[0],
                                  nil, val[1], nil)
                    }
                | kYIELD command_args
                    {
                      result = @builder.keyword_cmd(:yield, val[0],
                                  nil, val[1], nil)
                    }
                | kRETURN call_args
                    {
                      result = @builder.keyword_cmd(:return, val[0],
                                  nil, val[1], nil)
                    }
                | kBREAK call_args
                    {
                      result = @builder.keyword_cmd(:break, val[0],
                                  nil, val[1], nil)
                    }
                | kNEXT call_args
                    {
                      result = @builder.keyword_cmd(:next, val[0],
                                  nil, val[1], nil)
                    }

            mlhs: mlhs_basic
                    {
                      result = @builder.multi_lhs(nil, val[0], nil)
                    }
                | tLPAREN mlhs_inner rparen
                    {
                      result = @builder.begin(val[0], val[1], val[2])
                    }

      mlhs_inner: mlhs_basic
                    {
                      result = @builder.multi_lhs(nil, val[0], nil)
                    }
                | tLPAREN mlhs_inner rparen
                    {
                      result = @builder.multi_lhs(val[0], val[1], val[2])
                    }

      mlhs_basic: mlhs_head
                | mlhs_head mlhs_item
                    {
                      result = val[0].
                                  push(val[1])
                    }
                | mlhs_head tSTAR mlhs_node
                    {
                      result = val[0].
                                  push(@builder.splat(val[1], val[2]))
                    }
                | mlhs_head tSTAR mlhs_node tCOMMA mlhs_post
                    {
                      result = val[0].
                                  push(@builder.splat(val[1], val[2])).
                                  concat(val[4])
                    }
                | mlhs_head tSTAR
                    {
                      result = val[0].
                                  push(@builder.splat(val[1]))
                    }
                | mlhs_head tSTAR tCOMMA mlhs_post
                    {
                      result = val[0].
                                  push(@builder.splat(val[1])).
                                  concat(val[3])
                    }
                | tSTAR mlhs_node
                    {
                      result = [ @builder.splat(val[0], val[1]) ]
                    }
                | tSTAR mlhs_node tCOMMA mlhs_post
                    {
                      result = [ @builder.splat(val[0], val[1]),
                                 *val[3] ]
                    }
                | tSTAR
                    {
                      result = [ @builder.splat(val[0]) ]
                    }
                | tSTAR tCOMMA mlhs_post
                    {
                      result = [ @builder.splat(val[0]),
                                 *val[2] ]
                    }

       mlhs_item: mlhs_node
                | tLPAREN mlhs_inner rparen
                    {
                      result = @builder.begin(val[0], val[1], val[2])
                    }

       mlhs_head: mlhs_item tCOMMA
                    {
                      result = [ val[0] ]
                    }
                | mlhs_head mlhs_item tCOMMA
                    {
                      result = val[0] << val[1]
                    }

       mlhs_post: mlhs_item
                    {
                      result = [ val[0] ]
                    }
                | mlhs_post tCOMMA mlhs_item
                    {
                      result = val[0] << val[2]
                    }

       mlhs_node: user_variable
                    {
                      result = @builder.assignable(val[0])
                    }
                | keyword_variable
                    {
                      result = @builder.assignable(val[0])
                    }
                | primary_value tLBRACK2 opt_call_args rbracket
                    {
                      result = @builder.index_asgn(val[0], val[1], val[2], val[3])
                    }
                | primary_value tDOT tIDENTIFIER
                    {
                      result = @builder.attr_asgn(val[0], val[1], val[2])
                    }
                | primary_value tCOLON2 tIDENTIFIER
                    {
                      result = @builder.attr_asgn(val[0], val[1], val[2])
                    }
                | primary_value tDOT tCONSTANT
                    {
                      result = @builder.attr_asgn(val[0], val[1], val[2])
                    }
                | primary_value tCOLON2 tCONSTANT
                    {
                      result = @builder.assignable(
                                  @builder.const_fetch(val[0], val[1], val[2]))
                    }
                | tCOLON3 tCONSTANT
                    {
                      result = @builder.assignable(
                                  @builder.const_global(val[0], val[1]))
                    }
                | backref
                    {
                      result = @builder.assignable(val[0])
                    }

             lhs: user_variable
                    {
                      result = @builder.assignable(val[0])
                    }
                | keyword_variable
                    {
                      result = @builder.assignable(val[0])
                    }
                | primary_value tLBRACK2 opt_call_args rbracket
                    {
                      result = @builder.index_asgn(val[0], val[1], val[2], val[3])
                    }
                | primary_value tDOT tIDENTIFIER
                    {
                      result = @builder.attr_asgn(val[0], val[1], val[2])
                    }
                | primary_value tCOLON2 tIDENTIFIER
                    {
                      result = @builder.attr_asgn(val[0], val[1], val[2])
                    }
                | primary_value tDOT tCONSTANT
                    {
                      result = @builder.attr_asgn(val[0], val[1], val[2])
                    }
                | primary_value tCOLON2 tCONSTANT
                    {
                      result = @builder.assignable(
                                  @builder.const_fetch(val[0], val[1], val[2]))
                    }
                | tCOLON3 tCONSTANT
                    {
                      result = @builder.assignable(
                                  @builder.const_global(val[0], val[1]))
                    }
                | backref
                    {
                      result = @builder.assignable(val[0])
                    }

           cname: tIDENTIFIER
                    {
                      diagnostic :error, :module_name_const, nil, val[0]
                    }
                | tCONSTANT

           cpath: tCOLON3 cname
                    {
                      result = @builder.const_global(val[0], val[1])
                    }
                | cname
                    {
                      result = @builder.const(val[0])
                    }
                | primary_value tCOLON2 cname
                    {
                      result = @builder.const_fetch(val[0], val[1], val[2])
                    }

           fname: tIDENTIFIER | tCONSTANT | tFID
                | op
                | reswords

            fsym: fname
                    {
                      result = @builder.symbol(val[0])
                    }
                | symbol

           fitem: fsym
                | dsym

      undef_list: fitem
                    {
                      result = [ val[0] ]
                    }
                | undef_list tCOMMA
                    {
                      @lexer.state = :expr_fname
                    }
                    fitem
                    {
                      result = val[0] << val[3]
                    }

              op:   tPIPE    | tCARET  | tAMPER2  | tCMP  | tEQ     | tEQQ
                |   tMATCH   | tNMATCH | tGT      | tGEQ  | tLT     | tLEQ
                |   tNEQ     | tLSHFT  | tRSHFT   | tPLUS | tMINUS  | tSTAR2
                |   tSTAR    | tDIVIDE | tPERCENT | tPOW  | tBANG   | tTILDE
                |   tUPLUS   | tUMINUS | tAREF    | tASET | tDSTAR  | tBACK_REF2

        reswords: k__LINE__ | k__FILE__ | k__ENCODING__ | klBEGIN | klEND
                | kALIAS    | kAND      | kBEGIN        | kBREAK  | kCASE
                | kCLASS    | kDEF      | kDEFINED      | kDO     | kELSE
                | kELSIF    | kEND      | kENSURE       | kFALSE  | kFOR
                | kIN       | kMODULE   | kNEXT         | kNIL    | kNOT
                | kOR       | kREDO     | kRESCUE       | kRETRY  | kRETURN
                | kSELF     | kSUPER    | kTHEN         | kTRUE   | kUNDEF
                | kWHEN     | kYIELD    | kIF           | kUNLESS | kWHILE
                | kUNTIL

             arg: lhs tEQL arg
                    {
                      result = @builder.assign(val[0], val[1], val[2])
                    }
                | lhs tEQL arg kRESCUE_MOD arg
                    {
                      rescue_body = @builder.rescue_body(val[3],
                                        nil, nil, nil,
                                        nil, val[4])

                      rescue_ = @builder.begin_body(val[2], [ rescue_body ])

                      result  = @builder.assign(val[0], val[1], rescue_)
                    }
                | var_lhs tOP_ASGN arg
                    {
                      result = @builder.op_assign(val[0], val[1], val[2])
                    }
                | var_lhs tOP_ASGN arg kRESCUE_MOD arg
                    {
                      rescue_body = @builder.rescue_body(val[3],
                                        nil, nil, nil,
                                        nil, val[4])

                      rescue_ = @builder.begin_body(val[2], [ rescue_body ])

                      result = @builder.op_assign(val[0], val[1], rescue_)
                    }
                | primary_value tLBRACK2 opt_call_args rbracket tOP_ASGN arg
                    {
                      result = @builder.op_assign(
                                  @builder.index(
                                    val[0], val[1], val[2], val[3]),
                                  val[4], val[5])
                    }
                | primary_value tDOT tIDENTIFIER tOP_ASGN arg
                    {
                      result = @builder.op_assign(
                                  @builder.call_method(
                                    val[0], val[1], val[2]),
                                  val[3], val[4])
                    }
                | primary_value tDOT tCONSTANT tOP_ASGN arg
                    {
                      result = @builder.op_assign(
                                  @builder.call_method(
                                    val[0], val[1], val[2]),
                                  val[3], val[4])
                    }
                | primary_value tCOLON2 tIDENTIFIER tOP_ASGN arg
                    {
                      result = @builder.op_assign(
                                  @builder.call_method(
                                    val[0], val[1], val[2]),
                                  val[3], val[4])
                    }
                | primary_value tCOLON2 tCONSTANT tOP_ASGN arg
                    {
                      const  = @builder.const_op_assignable(
                                  @builder.const_fetch(val[0], val[1], val[2]))
                      result = @builder.op_assign(const, val[3], val[4])
                    }
                | tCOLON3 tCONSTANT tOP_ASGN arg
                    {
                      const  = @builder.const_op_assignable(
                                  @builder.const_global(val[0], val[1]))
                      result = @builder.op_assign(const, val[2], val[3])
                    }
                | backref tOP_ASGN arg
                    {
                      result = @builder.op_assign(val[0], val[1], val[2])
                    }
                | arg tDOT2 arg
                    {
                      result = @builder.range_inclusive(val[0], val[1], val[2])
                    }
                | arg tDOT3 arg
                    {
                      result = @builder.range_exclusive(val[0], val[1], val[2])
                    }
                | arg tPLUS arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tMINUS arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tSTAR2 arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tDIVIDE arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tPERCENT arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tPOW arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | tUMINUS_NUM tINTEGER tPOW arg
                    {
                      result = @builder.unary_op(val[0],
                                  @builder.binary_op(
                                    @builder.integer(val[1]),
                                      val[2], val[3]))
                    }
                | tUMINUS_NUM tFLOAT tPOW arg
                    {
                      result = @builder.unary_op(val[0],
                                  @builder.binary_op(
                                    @builder.float(val[1]),
                                      val[2], val[3]))
                    }
                | tUPLUS arg
                    {
                      result = @builder.unary_op(val[0], val[1])
                    }
                | tUMINUS arg
                    {
                      result = @builder.unary_op(val[0], val[1])
                    }
                | arg tPIPE arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tCARET arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tAMPER2 arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tCMP arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tGT arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tGEQ arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tLT arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tLEQ arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tEQ arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tEQQ arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tNEQ arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tMATCH arg
                    {
                      result = @builder.match_op(val[0], val[1], val[2])
                    }
                | arg tNMATCH arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | tBANG arg
                    {
                      result = @builder.not_op(val[0], nil, val[1], nil)
                    }
                | tTILDE arg
                    {
                      result = @builder.unary_op(val[0], val[1])
                    }
                | arg tLSHFT arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tRSHFT arg
                    {
                      result = @builder.binary_op(val[0], val[1], val[2])
                    }
                | arg tANDOP arg
                    {
                      result = @builder.logical_op(:and, val[0], val[1], val[2])
                    }
                | arg tOROP arg
                    {
                      result = @builder.logical_op(:or, val[0], val[1], val[2])
                    }
                | kDEFINED opt_nl arg
                    {
                      result = @builder.keyword_cmd(:defined?, val[0], nil, [ val[2] ], nil)
                    }

                | arg tEH arg opt_nl tCOLON arg
                    {
                      result = @builder.ternary(val[0], val[1],
                                                val[2], val[4], val[5])
                    }
                | primary

       arg_value: arg

       aref_args: none
                | args trailer
                | args tCOMMA assocs trailer
                    {
                      result = val[0] << @builder.associate(nil, val[2], nil)
                    }
                | assocs trailer
                    {
                      result = [ @builder.associate(nil, val[0], nil) ]
                    }

      paren_args: tLPAREN2 opt_call_args rparen
                    {
                      result = val
                    }

  opt_paren_args: # nothing
                    {
                      result = [ nil, [], nil ]
                    }
                | paren_args

   opt_call_args: # nothing
                    {
                      result = []
                    }
                | call_args
                | args tCOMMA
                | args tCOMMA assocs tCOMMA
                    {
                      result = val[0] << @builder.associate(nil, val[2], nil)
                    }
                | assocs tCOMMA
                    {
                      result = [ @builder.associate(nil, val[0], nil) ]
                    }

       call_args: command
                    {
                      result = [ val[0] ]
                    }
                | args opt_block_arg
                    {
                      result = val[0].concat(val[1])
                    }
                | assocs opt_block_arg
                    {
                      result = [ @builder.associate(nil, val[0], nil) ]
                      result.concat(val[1])
                    }
                | args tCOMMA assocs opt_block_arg
                    {
                      assocs = @builder.associate(nil, val[2], nil)
                      result = val[0] << assocs
                      result.concat(val[3])
                    }
                | block_arg
                    {
                      result =  [ val[0] ]
                    }

    command_args:   {
                      result = @lexer.cmdarg.dup
                      @lexer.cmdarg.push(true)
                    }
                  call_args
                    {
                      @lexer.cmdarg = val[0]

                      result = val[1]
                    }

       block_arg: tAMPER arg_value
                    {
                      result = @builder.block_pass(val[0], val[1])
                    }

   opt_block_arg: tCOMMA block_arg
                    {
                      result = [ val[1] ]
                    }
                | # nothing
                    {
                      result = []
                    }

            args: arg_value
                    {
                      result = [ val[0] ]
                    }
                | tSTAR arg_value
                    {
                      result = [ @builder.splat(val[0], val[1]) ]
                    }
                | args tCOMMA arg_value
                    {
                      result = val[0] << val[2]
                    }
                | args tCOMMA tSTAR arg_value
                    {
                      result = val[0] << @builder.splat(val[2], val[3])
                    }

            mrhs: args tCOMMA arg_value
                    {
                      result = val[0] << val[2]
                    }
                | args tCOMMA tSTAR arg_value
                    {
                      result = val[0] << @builder.splat(val[2], val[3])
                    }
                | tSTAR arg_value
                    {
                      result = [ @builder.splat(val[0], val[1]) ]
                    }

         primary: literal
                | strings
                | xstring
                | regexp
                | words
                | qwords
                | symbols
                | qsymbols
                | var_ref
                | backref
                | tFID
                    {
                      result = @builder.call_method(nil, nil, val[0])
                    }
                | kBEGIN
                    {
                      result = @lexer.cmdarg.dup
                      @lexer.cmdarg.clear
                    }
                    bodystmt kEND
                    {
                      @lexer.cmdarg = val[1]

                      result = @builder.begin_keyword(val[0], val[2], val[3])
                    }
                | tLPAREN_ARG
                    {
                      result = @lexer.cmdarg.dup
                      @lexer.cmdarg.clear
                    }
                    expr
                    {
                      @lexer.state = :expr_endarg
                    }
                    opt_nl tRPAREN
                    {
                      @lexer.cmdarg = val[1]

                      result = @builder.begin(val[0], val[2], val[5])
                    }
                | tLPAREN_ARG
                    {
                      @lexer.state = :expr_endarg
                    }
                    opt_nl tRPAREN
                    {
                      result = @builder.begin(val[0], nil, val[3])
                    }
                | tLPAREN compstmt tRPAREN
                    {
                      result = @builder.begin(val[0], val[1], val[2])
                    }
                | primary_value tCOLON2 tCONSTANT
                    {
                      result = @builder.const_fetch(val[0], val[1], val[2])
                    }
                | tCOLON3 tCONSTANT
                    {
                      result = @builder.const_global(val[0], val[1])
                    }
                | tLBRACK aref_args tRBRACK
                    {
                      result = @builder.array(val[0], val[1], val[2])
                    }
                | tLBRACE assoc_list tRCURLY
                    {
                      result = @builder.associate(val[0], val[1], val[2])
                    }
                | kRETURN
                    {
                      result = @builder.keyword_cmd(:return, val[0])
                    }
                | kYIELD tLPAREN2 call_args rparen
                    {
                      result = @builder.keyword_cmd(:yield, val[0], val[1], val[2], val[3])
                    }
                | kYIELD tLPAREN2 rparen
                    {
                      result = @builder.keyword_cmd(:yield, val[0], val[1], [], val[2])
                    }
                | kYIELD
                    {
                      result = @builder.keyword_cmd(:yield, val[0])
                    }
                | kDEFINED opt_nl tLPAREN2 expr rparen
                    {
                      result = @builder.keyword_cmd(:defined?, val[0],
                                                    val[2], [ val[3] ], val[4])
                    }
                | kNOT tLPAREN2 expr rparen
                    {
                      result = @builder.not_op(val[0], val[1], val[2], val[3])
                    }
                | kNOT tLPAREN2 rparen
                    {
                      result = @builder.not_op(val[0], val[1], nil, val[2])
                    }
                | fcall brace_block
                    {
                      method_call = @builder.call_method(nil, nil, val[0])

                      begin_t, args, body, end_t = val[1]
                      result      = @builder.block(method_call,
                                      begin_t, args, body, end_t)
                    }
                | method_call
                | method_call brace_block
                    {
                      begin_t, args, body, end_t = val[1]
                      result      = @builder.block(val[0],
                                      begin_t, args, body, end_t)
                    }
                | tLAMBDA lambda
                    {
                      lambda_call = @builder.call_lambda(val[0])

                      args, (begin_t, body, end_t) = val[1]
                      result      = @builder.block(lambda_call,
                                      begin_t, args, body, end_t)
                    }
                | kIF expr_value then compstmt if_tail kEND
                    {
                      else_t, else_ = val[4]
                      result = @builder.condition(val[0], val[1], val[2],
                                                  val[3], else_t,
                                                  else_,  val[5])
                    }
                | kUNLESS expr_value then compstmt opt_else kEND
                    {
                      else_t, else_ = val[4]
                      result = @builder.condition(val[0], val[1], val[2],
                                                  else_,  else_t,
                                                  val[3], val[5])
                    }
                | kWHILE
                    {
                      @lexer.cond.push(true)
                    }
                    expr_value do
                    {
                      @lexer.cond.pop
                    }
                    compstmt kEND
                    {
                      result = @builder.loop(:while, val[0], val[2], val[3],
                                             val[5], val[6])
                    }
                | kUNTIL
                    {
                      @lexer.cond.push(true)
                    }
                    expr_value do
                    {
                      @lexer.cond.pop
                    }
                    compstmt kEND
                    {
                      result = @builder.loop(:until, val[0], val[2], val[3],
                                             val[5], val[6])
                    }
                | kCASE expr_value opt_terms case_body kEND
                    {
                      *when_bodies, (else_t, else_body) = *val[3]

                      result = @builder.case(val[0], val[1],
                                             when_bodies, else_t, else_body,
                                             val[4])
                    }
                | kCASE            opt_terms case_body kEND
                    {
                      *when_bodies, (else_t, else_body) = *val[2]

                      result = @builder.case(val[0], nil,
                                             when_bodies, else_t, else_body,
                                             val[3])
                    }
                | kFOR for_var kIN
                    {
                      @lexer.cond.push(true)
                    }
                    expr_value do
                    {
                      @lexer.cond.pop
                    }
                    compstmt kEND
                    {
                      result = @builder.for(val[0], val[1],
                                            val[2], val[4],
                                            val[5], val[7], val[8])
                    }
                | kCLASS cpath superclass
                    {
                      @static_env.extend_static
                      @lexer.push_cmdarg
                    }
                    bodystmt kEND
                    {
                      if in_def?
                        diagnostic :error, :class_in_def, nil, val[0]
                      end

                      lt_t, superclass = val[2]
                      result = @builder.def_class(val[0], val[1],
                                                  lt_t, superclass,
                                                  val[4], val[5])

                      @lexer.pop_cmdarg
                      @static_env.unextend
                    }
                | kCLASS tLSHFT expr term
                    {
                      result = @def_level
                      @def_level = 0

                      @static_env.extend_static
                      @lexer.push_cmdarg
                    }
                    bodystmt kEND
                    {
                      result = @builder.def_sclass(val[0], val[1], val[2],
                                                   val[5], val[6])

                      @lexer.pop_cmdarg
                      @static_env.unextend

                      @def_level = val[4]
                    }
                | kMODULE cpath
                    {
                      @static_env.extend_static
                      @lexer.push_cmdarg
                    }
                    bodystmt kEND
                    {
                      if in_def?
                        diagnostic :error, :module_in_def, nil, val[0]
                      end

                      result = @builder.def_module(val[0], val[1],
                                                   val[3], val[4])

                      @lexer.pop_cmdarg
                      @static_env.unextend
                    }
                | kDEF fname
                    {
                      @def_level += 1
                      @static_env.extend_static
                      @lexer.push_cmdarg
                    }
                    f_arglist bodystmt kEND
                    {
                      result = @builder.def_method(val[0], val[1],
                                  val[3], val[4], val[5])

                      @lexer.pop_cmdarg
                      @static_env.unextend
                      @def_level -= 1
                    }
                | kDEF singleton dot_or_colon
                    {
                      @lexer.state = :expr_fname
                    }
                    fname
                    {
                      @def_level += 1
                      @static_env.extend_static
                      @lexer.push_cmdarg
                    }
                    f_arglist bodystmt kEND
                    {
                      result = @builder.def_singleton(val[0], val[1], val[2],
                                  val[4], val[6], val[7], val[8])

                      @lexer.pop_cmdarg
                      @static_env.unextend
                      @def_level -= 1
                    }
                | kBREAK
                    {
                      result = @builder.keyword_cmd(:break, val[0])
                    }
                | kNEXT
                    {
                      result = @builder.keyword_cmd(:next, val[0])
                    }
                | kREDO
                    {
                      result = @builder.keyword_cmd(:redo, val[0])
                    }
                | kRETRY
                    {
                      result = @builder.keyword_cmd(:retry, val[0])
                    }

   primary_value: primary

            then: term
                | kTHEN
                | term kTHEN
                    {
                      result = val[1]
                    }

              do: term
                | kDO_COND

         if_tail: opt_else
                | kELSIF expr_value then compstmt if_tail
                    {
                      else_t, else_ = val[4]
                      result = [ val[0],
                                 @builder.condition(val[0], val[1], val[2],
                                                    val[3], else_t,
                                                    else_,  nil),
                               ]
                    }

        opt_else: none
                | kELSE compstmt
                    {
                      result = val
                    }

         for_var: lhs
                | mlhs

          f_marg: f_norm_arg
                    {
                      @static_env.declare val[0][0]

                      result = @builder.arg(val[0])
                    }
                | tLPAREN f_margs rparen
                    {
                      result = @builder.multi_lhs(val[0], val[1], val[2])
                    }

     f_marg_list: f_marg
                    {
                      result = [ val[0] ]
                    }
                | f_marg_list tCOMMA f_marg
                    {
                      result = val[0] << val[2]
                    }

         f_margs: f_marg_list
                | f_marg_list tCOMMA tSTAR f_norm_arg
                    {
                      @static_env.declare val[3][0]

                      result = val[0].
                                  push(@builder.restarg(val[2], val[3]))
                    }
                | f_marg_list tCOMMA tSTAR f_norm_arg tCOMMA f_marg_list
                    {
                      @static_env.declare val[3][0]

                      result = val[0].
                                  push(@builder.restarg(val[2], val[3])).
                                  concat(val[5])
                    }
                | f_marg_list tCOMMA tSTAR
                    {
                      result = val[0].
                                  push(@builder.restarg(val[2]))
                    }
                | f_marg_list tCOMMA tSTAR            tCOMMA f_marg_list
                    {
                      result = val[0].
                                  push(@builder.restarg(val[2])).
                                  concat(val[4])
                    }
                |                    tSTAR f_norm_arg
                    {
                      @static_env.declare val[1][0]

                      result = [ @builder.restarg(val[0], val[1]) ]
                    }
                |                    tSTAR f_norm_arg tCOMMA f_marg_list
                    {
                      @static_env.declare val[1][0]

                      result = [ @builder.restarg(val[0], val[1]),
                                 *val[3] ]
                    }
                |                    tSTAR
                    {
                      result = [ @builder.restarg(val[0]) ]
                    }
                |                    tSTAR tCOMMA f_marg_list
                    {
                      result = [ @builder.restarg(val[0]),
                                 *val[2] ]
                    }

 block_args_tail: f_block_kwarg tCOMMA f_kwrest opt_f_block_arg
                    {
                      result = val[0].concat(val[2]).concat(val[3])
                    }
                | f_block_kwarg opt_f_block_arg
                    {
                      result = val[0].concat(val[1])
                    }
                | f_kwrest opt_f_block_arg
                    {
                      result = val[0].concat(val[1])
                    }
                | f_block_arg
                    {
                      result = [ val[0] ]
                    }

opt_block_args_tail:
                  tCOMMA block_args_tail
                    {
                      result = val[1]
                    }
                | # nothing
                    {
                      result = []
                    }

     block_param: f_arg tCOMMA f_block_optarg tCOMMA f_rest_arg              opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[5])
                    }
                | f_arg tCOMMA f_block_optarg tCOMMA f_rest_arg tCOMMA f_arg opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[6]).
                                  concat(val[7])
                    }
                | f_arg tCOMMA f_block_optarg                                opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                | f_arg tCOMMA f_block_optarg tCOMMA                   f_arg opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[5])
                    }
                | f_arg tCOMMA                       f_rest_arg              opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                | f_arg tCOMMA
                | f_arg tCOMMA                       f_rest_arg tCOMMA f_arg opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[5])
                    }
                | f_arg                                                      opt_block_args_tail
                    {
                      result = val[0].concat(val[1])
                    }
                | f_block_optarg tCOMMA              f_rest_arg              opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                | f_block_optarg tCOMMA              f_rest_arg tCOMMA f_arg opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[5])
                    }
                | f_block_optarg                                             opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[1])
                    }
                | f_block_optarg tCOMMA                                f_arg opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                |                                    f_rest_arg              opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[1])
                    }
                |                                    f_rest_arg tCOMMA f_arg opt_block_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                |                                                                block_args_tail

 opt_block_param: # nothing
                    {
                      result = @builder.args(nil, [], nil)
                    }
                | block_param_def
                    {
                      @lexer.state = :expr_value
                    }

 block_param_def: tPIPE opt_bv_decl tPIPE
                    {
                      result = @builder.args(val[0], val[1], val[2])
                    }
                | tOROP
                    {
                      result = @builder.args(val[0], [], val[0])
                    }
                | tPIPE block_param opt_bv_decl tPIPE
                    {
                      result = @builder.args(val[0], val[1].concat(val[2]), val[3])
                    }

     opt_bv_decl: opt_nl
                    {
                      result = []
                    }
                | opt_nl tSEMI bv_decls opt_nl
                    {
                      result = val[2]
                    }

        bv_decls: bvar
                    {
                      result = [ val[0] ]
                    }
                | bv_decls tCOMMA bvar
                    {
                      result = val[0] << val[2]
                    }

            bvar: tIDENTIFIER
                    {
                      result = @builder.shadowarg(val[0])
                    }
                | f_bad_arg

          lambda:   {
                      @static_env.extend_dynamic
                    }
                  f_larglist lambda_body
                    {
                      result = [ val[1], val[2] ]

                      @static_env.unextend
                    }

     f_larglist: tLPAREN2 f_args opt_bv_decl tRPAREN
                    {
                      result = @builder.args(val[0], val[1].concat(val[2]), val[3])
                    }
                | f_args
                    {
                      result = @builder.args(nil, val[0], nil)
                    }

     lambda_body: tLAMBEG compstmt tRCURLY
                    {
                      result = [ val[0], val[1], val[2] ]
                    }
                | kDO_LAMBDA compstmt kEND
                    {
                      result = [ val[0], val[1], val[2] ]
                    }

        do_block: kDO_BLOCK
                    {
                      @static_env.extend_dynamic
                    }
                    opt_block_param compstmt kEND
                    {
                      result = [ val[0], val[2], val[3], val[4] ]

                      @static_env.unextend
                    }

      block_call: command do_block
                    {
                      begin_t, block_args, body, end_t = val[1]
                      result      = @builder.block(val[0],
                                      begin_t, block_args, body, end_t)
                    }
                | block_call dot_or_colon operation2 opt_paren_args
                    {
                      lparen_t, args, rparen_t = val[3]
                      result = @builder.call_method(val[0], val[1], val[2],
                                  lparen_t, args, rparen_t)
                    }
                | block_call dot_or_colon operation2 opt_paren_args brace_block
                    {
                      lparen_t, args, rparen_t = val[3]
                      method_call = @builder.call_method(val[0], val[1], val[2],
                                      lparen_t, args, rparen_t)

                      begin_t, args, body, end_t = val[4]
                      result      = @builder.block(method_call,
                                      begin_t, args, body, end_t)
                    }
                | block_call dot_or_colon operation2 command_args do_block
                    {
                      method_call = @builder.call_method(val[0], val[1], val[2],
                                      nil, val[3], nil)

                      begin_t, args, body, end_t = val[4]
                      result      = @builder.block(method_call,
                                      begin_t, args, body, end_t)
                    }

     method_call: fcall paren_args
                    {
                      lparen_t, args, rparen_t = val[1]
                      result = @builder.call_method(nil, nil, val[0],
                                  lparen_t, args, rparen_t)
                    }
                | primary_value tDOT operation2 opt_paren_args
                    {
                      lparen_t, args, rparen_t = val[3]
                      result = @builder.call_method(val[0], val[1], val[2],
                                  lparen_t, args, rparen_t)
                    }
                | primary_value tCOLON2 operation2 paren_args
                    {
                      lparen_t, args, rparen_t = val[3]
                      result = @builder.call_method(val[0], val[1], val[2],
                                  lparen_t, args, rparen_t)
                    }
                | primary_value tCOLON2 operation3
                    {
                      result = @builder.call_method(val[0], val[1], val[2])
                    }
                | primary_value tDOT paren_args
                    {
                      lparen_t, args, rparen_t = val[2]
                      result = @builder.call_method(val[0], val[1], nil,
                                  lparen_t, args, rparen_t)
                    }
                | primary_value tCOLON2 paren_args
                    {
                      lparen_t, args, rparen_t = val[2]
                      result = @builder.call_method(val[0], val[1], nil,
                                  lparen_t, args, rparen_t)
                    }
                | kSUPER paren_args
                    {
                      lparen_t, args, rparen_t = val[1]
                      result = @builder.keyword_cmd(:super, val[0],
                                  lparen_t, args, rparen_t)
                    }
                | kSUPER
                    {
                      result = @builder.keyword_cmd(:zsuper, val[0])
                    }
                | primary_value tLBRACK2 opt_call_args rbracket
                    {
                      result = @builder.index(val[0], val[1], val[2], val[3])
                    }

     brace_block: tLCURLY
                    {
                      @static_env.extend_dynamic
                    }
                    opt_block_param compstmt tRCURLY
                    {
                      result = [ val[0], val[2], val[3], val[4] ]

                      @static_env.unextend
                    }
                | kDO
                    {
                      @static_env.extend_dynamic
                    }
                 opt_block_param compstmt kEND
                    {
                      result = [ val[0], val[2], val[3], val[4] ]

                      @static_env.unextend
                    }

       case_body: kWHEN args then compstmt cases
                    {
                      result = [ @builder.when(val[0], val[1], val[2], val[3]),
                                 *val[4] ]
                    }

           cases: opt_else
                    {
                      result = [ val[0] ]
                    }
                | case_body

      opt_rescue: kRESCUE exc_list exc_var then compstmt opt_rescue
                    {
                      assoc_t, exc_var = val[2]

                      if val[1]
                        exc_list = @builder.array(nil, val[1], nil)
                      end

                      result = [ @builder.rescue_body(val[0],
                                      exc_list, assoc_t, exc_var,
                                      val[3], val[4]),
                                 *val[5] ]
                    }
                |
                    {
                      result = []
                    }

        exc_list: arg_value
                    {
                      result = [ val[0] ]
                    }
                | mrhs
                | none

         exc_var: tASSOC lhs
                    {
                      result = [ val[0], val[1] ]
                    }
                | none

      opt_ensure: kENSURE compstmt
                    {
                      result = [ val[0], val[1] ]
                    }
                | none

         literal: numeric
                | symbol
                | dsym

         strings: string
                    {
                      result = @builder.string_compose(nil, val[0], nil)
                    }

          string: string1
                    {
                      result = [ val[0] ]
                    }
                | string string1
                    {
                      result = val[0] << val[1]
                    }

         string1: tSTRING_BEG string_contents tSTRING_END
                    {
                      result = @builder.string_compose(val[0], val[1], val[2])
                    }
                | tSTRING
                    {
                      result = @builder.string(val[0])
                    }
                | tCHARACTER
                    {
                      result = @builder.character(val[0])
                    }

         xstring: tXSTRING_BEG xstring_contents tSTRING_END
                    {
                      result = @builder.xstring_compose(val[0], val[1], val[2])
                    }

          regexp: tREGEXP_BEG regexp_contents tSTRING_END tREGEXP_OPT
                    {
                      opts   = @builder.regexp_options(val[3])
                      result = @builder.regexp_compose(val[0], val[1], val[2], opts)
                    }

           words: tWORDS_BEG word_list tSTRING_END
                    {
                      result = @builder.words_compose(val[0], val[1], val[2])
                    }

       word_list: # nothing
                    {
                      result = []
                    }
                | word_list word tSPACE
                    {
                      result = val[0] << @builder.word(val[1])
                    }

            word: string_content
                    {
                      result = [ val[0] ]
                    }
                | word string_content
                    {
                      result = val[0] << val[1]
                    }

         symbols: tSYMBOLS_BEG symbol_list tSTRING_END
                    {
                      result = @builder.symbols_compose(val[0], val[1], val[2])
                    }

     symbol_list: # nothing
                    {
                      result = []
                    }
                | symbol_list word tSPACE
                    {
                      result = val[0] << @builder.word(val[1])
                    }

          qwords: tQWORDS_BEG qword_list tSTRING_END
                    {
                      result = @builder.words_compose(val[0], val[1], val[2])
                    }

        qsymbols: tQSYMBOLS_BEG qsym_list tSTRING_END
                    {
                      result = @builder.symbols_compose(val[0], val[1], val[2])
                    }

      qword_list: # nothing
                    {
                      result = []
                    }
                | qword_list tSTRING_CONTENT tSPACE
                    {
                      result = val[0] << @builder.string_internal(val[1])
                    }

       qsym_list: # nothing
                    {
                      result = []
                    }
                | qsym_list tSTRING_CONTENT tSPACE
                    {
                      result = val[0] << @builder.symbol_internal(val[1])
                    }

 string_contents: # nothing
                    {
                      result = []
                    }
                | string_contents string_content
                    {
                      result = val[0] << val[1]
                    }

xstring_contents: # nothing
                    {
                      result = []
                    }
                | xstring_contents string_content
                    {
                      result = val[0] << val[1]
                    }

regexp_contents: # nothing
                    {
                      result = []
                    }
                | regexp_contents string_content
                    {
                      result = val[0] << val[1]
                    }

  string_content: tSTRING_CONTENT
                    {
                      result = @builder.string_internal(val[0])
                    }
                | tSTRING_DVAR string_dvar
                    {
                      result = val[1]
                    }
                | tSTRING_DBEG
                    {
                      @lexer.cond.push(false)
                      @lexer.cmdarg.push(false)
                    }
                    compstmt tSTRING_DEND
                    {
                      @lexer.cond.lexpop
                      @lexer.cmdarg.lexpop

                      result = @builder.begin(val[0], val[2], val[3])
                    }

     string_dvar: tGVAR
                    {
                      result = @builder.gvar(val[0])
                    }
                | tIVAR
                    {
                      result = @builder.ivar(val[0])
                    }
                | tCVAR
                    {
                      result = @builder.cvar(val[0])
                    }
                | backref


          symbol: tSYMBOL
                    {
                      result = @builder.symbol(val[0])
                    }

            dsym: tSYMBEG xstring_contents tSTRING_END
                    {
                      result = @builder.symbol_compose(val[0], val[1], val[2])
                    }

         numeric: tINTEGER
                    {
                      result = @builder.integer(val[0])
                    }
                | tFLOAT
                    {
                      result = @builder.float(val[0])
                    }
                | tUMINUS_NUM tINTEGER =tLOWEST
                    {
                      result = @builder.negate(val[0],
                                  @builder.integer(val[1]))
                    }
                | tUMINUS_NUM tFLOAT   =tLOWEST
                    {
                      result = @builder.negate(val[0],
                                  @builder.float(val[1]))
                    }

   user_variable: tIDENTIFIER
                    {
                      result = @builder.ident(val[0])
                    }
                | tIVAR
                    {
                      result = @builder.ivar(val[0])
                    }
                | tGVAR
                    {
                      result = @builder.gvar(val[0])
                    }
                | tCONSTANT
                    {
                      result = @builder.const(val[0])
                    }
                | tCVAR
                    {
                      result = @builder.cvar(val[0])
                    }

keyword_variable: kNIL
                    {
                      result = @builder.nil(val[0])
                    }
                | kSELF
                    {
                      result = @builder.self(val[0])
                    }
                | kTRUE
                    {
                      result = @builder.true(val[0])
                    }
                | kFALSE
                    {
                      result = @builder.false(val[0])
                    }
                | k__FILE__
                    {
                      result = @builder.__FILE__(val[0])
                    }
                | k__LINE__
                    {
                      result = @builder.__LINE__(val[0])
                    }
                | k__ENCODING__
                    {
                      result = @builder.__ENCODING__(val[0])
                    }

         var_ref: user_variable
                    {
                      result = @builder.accessible(val[0])
                    }
                | keyword_variable
                    {
                      result = @builder.accessible(val[0])
                    }

         var_lhs: user_variable
                    {
                      result = @builder.assignable(val[0])
                    }
                | keyword_variable
                    {
                      result = @builder.assignable(val[0])
                    }

         backref: tNTH_REF
                    {
                      result = @builder.nth_ref(val[0])
                    }
                | tBACK_REF
                    {
                      result = @builder.back_ref(val[0])
                    }

      superclass: term
                    {
                      result = nil
                    }
                | tLT
                    {
                      @lexer.state = :expr_value
                    }
                    expr_value term
                    {
                      result = [ val[0], val[2] ]
                    }
                | error term
                    {
                      yyerrok
                      result = nil
                    }

       f_arglist: tLPAREN2 f_args rparen
                    {
                      result = @builder.args(val[0], val[1], val[2])

                      @lexer.state = :expr_value
                    }
                | f_args term
                    {
                      result = @builder.args(nil, val[0], nil)
                    }

       args_tail: f_kwarg tCOMMA f_kwrest opt_f_block_arg
                    {
                      result = val[0].concat(val[2]).concat(val[3])
                    }
                | f_kwarg opt_f_block_arg
                    {
                      result = val[0].concat(val[1])
                    }
                | f_kwrest opt_f_block_arg
                    {
                      result = val[0].concat(val[1])
                    }
                | f_block_arg
                    {
                      result = [ val[0] ]
                    }

   opt_args_tail: tCOMMA args_tail
                    {
                      result = val[1]
                    }
                | # nothing
                    {
                      result = []
                    }

          f_args: f_arg tCOMMA f_optarg tCOMMA f_rest_arg              opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[5])
                    }
                | f_arg tCOMMA f_optarg tCOMMA f_rest_arg tCOMMA f_arg opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[6]).
                                  concat(val[7])
                    }
                | f_arg tCOMMA f_optarg                                opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                | f_arg tCOMMA f_optarg tCOMMA                   f_arg opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[5])
                    }
                | f_arg tCOMMA                 f_rest_arg              opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                | f_arg tCOMMA                 f_rest_arg tCOMMA f_arg opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[5])
                    }
                | f_arg                                                opt_args_tail
                    {
                      result = val[0].
                                  concat(val[1])
                    }
                |              f_optarg tCOMMA f_rest_arg              opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                |              f_optarg tCOMMA f_rest_arg tCOMMA f_arg opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[4]).
                                  concat(val[5])
                    }
                |              f_optarg                                opt_args_tail
                    {
                      result = val[0].
                                  concat(val[1])
                    }
                |              f_optarg tCOMMA                   f_arg opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                |                              f_rest_arg              opt_args_tail
                    {
                      result = val[0].
                                  concat(val[1])
                    }
                |                              f_rest_arg tCOMMA f_arg opt_args_tail
                    {
                      result = val[0].
                                  concat(val[2]).
                                  concat(val[3])
                    }
                |                                                          args_tail
                    {
                      result = val[0]
                    }
                | # nothing
                    {
                      result = []
                    }

       f_bad_arg: tCONSTANT
                    {
                      diagnostic :error, :argument_const, nil, val[0]
                    }
                | tIVAR
                    {
                      diagnostic :error, :argument_ivar, nil, val[0]
                    }
                | tGVAR
                    {
                      diagnostic :error, :argument_gvar, nil, val[0]
                    }
                | tCVAR
                    {
                      diagnostic :error, :argument_cvar, nil, val[0]
                    }

      f_norm_arg: f_bad_arg
                | tIDENTIFIER

      f_arg_item: f_norm_arg
                    {
                      @static_env.declare val[0][0]

                      result = @builder.arg(val[0])
                    }
                | tLPAREN f_margs rparen
                    {
                      result = @builder.multi_lhs(val[0], val[1], val[2])
                    }

           f_arg: f_arg_item
                    {
                      result = [ val[0] ]
                    }
                | f_arg tCOMMA f_arg_item
                    {
                      result = val[0] << val[2]
                    }

            f_kw: tLABEL arg_value
                    {
                      check_kwarg_name(val[0])

                      @static_env.declare val[0][0]

                      result = @builder.kwoptarg(val[0], val[1])
                    }

      f_block_kw: tLABEL primary_value
                    {
                      check_kwarg_name(val[0])

                      @static_env.declare val[0][0]

                      result = @builder.kwoptarg(val[0], val[1])
                    }

   f_block_kwarg: f_block_kw
                    {
                      result = [ val[0] ]
                    }
                | f_block_kwarg tCOMMA f_block_kw
                    {
                      result = val[0] << val[2]
                    }

         f_kwarg: f_kw
                    {
                      result = [ val[0] ]
                    }
                | f_kwarg tCOMMA f_kw
                    {
                      result = val[0] << val[2]
                    }

     kwrest_mark: tPOW | tDSTAR

        f_kwrest: kwrest_mark tIDENTIFIER
                    {
                      @static_env.declare val[1][0]

                      result = [ @builder.kwrestarg(val[0], val[1]) ]
                    }
                | kwrest_mark
                    {
                      result = [ @builder.kwrestarg(val[0]) ]
                    }

           f_opt: tIDENTIFIER tEQL arg_value
                    {
                      @static_env.declare val[0][0]

                      result = @builder.optarg(val[0], val[1], val[2])
                    }

     f_block_opt: tIDENTIFIER tEQL primary_value
                    {
                      @static_env.declare val[0][0]

                      result = @builder.optarg(val[0], val[1], val[2])
                    }

  f_block_optarg: f_block_opt
                    {
                      result = [ val[0] ]
                    }
                | f_block_optarg tCOMMA f_block_opt
                    {
                      result = val[0] << val[2]
                    }

        f_optarg: f_opt
                    {
                      result = [ val[0] ]
                    }
                | f_optarg tCOMMA f_opt
                    {
                      result = val[0] << val[2]
                    }

    restarg_mark: tSTAR2 | tSTAR

      f_rest_arg: restarg_mark tIDENTIFIER
                    {
                      @static_env.declare val[1][0]

                      result = [ @builder.restarg(val[0], val[1]) ]
                    }
                | restarg_mark
                    {
                      result = [ @builder.restarg(val[0]) ]
                    }

     blkarg_mark: tAMPER2 | tAMPER

     f_block_arg: blkarg_mark tIDENTIFIER
                    {
                      @static_env.declare val[1][0]

                      result = @builder.blockarg(val[0], val[1])
                    }

 opt_f_block_arg: tCOMMA f_block_arg
                    {
                      result = [ val[1] ]
                    }
                |
                    {
                      result = []
                    }

       singleton: var_ref
                | tLPAREN2 expr rparen
                    {
                      result = val[1]
                    }

      assoc_list: # nothing
                    {
                      result = []
                    }
                | assocs trailer

          assocs: assoc
                    {
                      result = [ val[0] ]
                    }
                | assocs tCOMMA assoc
                    {
                      result = val[0] << val[2]
                    }

           assoc: arg_value tASSOC arg_value
                    {
                      result = @builder.pair(val[0], val[1], val[2])
                    }
                | tLABEL arg_value
                    {
                      result = @builder.pair_keyword(val[0], val[1])
                    }
                | tDSTAR arg_value
                    {
                      result = @builder.kwsplat(val[0], val[1])
                    }

       operation: tIDENTIFIER | tCONSTANT | tFID
      operation2: tIDENTIFIER | tCONSTANT | tFID | op
      operation3: tIDENTIFIER | tFID | op
    dot_or_colon: tDOT | tCOLON2
       opt_terms:  | terms
          opt_nl:  | tNL
          rparen: opt_nl tRPAREN
                    {
                      result = val[1]
                    }
        rbracket: opt_nl tRBRACK
                    {
                      result = val[1]
                    }
         trailer:  | tNL | tCOMMA

            term: tSEMI
                  {
                    yyerrok
                  }
                | tNL

           terms: term
                | terms tSEMI

            none: # nothing
                  {
                    result = nil
                  }
end

---- header

require 'parser'

Parser.check_for_encoding_support

---- inner

  def version
    20
  end

  def default_encoding
    Encoding::UTF_8
  end
