The type RE_Elem

RE_Elem is a tree like structure with nodes. When the compiler in package Y2018-Text-Jets-Compiler compiles the regular expression the result is a linked list with nodes of type RE_Elem, in this paper this is called the ‘syntax tree’. After the compilation the syntax tree is cleaned up and and nodes marked as only in the translation are converted to REQ_CLASS nodes.

The fixed part of RE_Elem

• id : RE_ID – identifier of a node
• left : RE_Elem_AC – left link
• right : RE_Elem_AC – right link
• V : REQ_TY – identifier of the variable part

The variable part consists of one of

• REQ_BEGIN
  • begin_circumflex : Boolean - if expression starts with ^-character
    
  • begin_dollar : Boolean - if expression ends with $-character
    
• REQ_CHAR
  • char_value : CodePoint
  • char_negative : Boolean - not this value
    
  • char_min : Integer – 0:Integer'Last
  • char_max : Integer
  • char_greedy : Boolean
  • char_maxORG : Integer - orginal char_max value from compilation
    
  • char_greedy : Boolean
    
• REQ_PERIOD
  • period_min : Integer – 0:Integer'Last
  • period_max : Integer
  • period_maxORG: Integer - orginal period_max value from compilation
  • period_greedy : Boolean
• REQ_CLASS_ELEM (Exists only during translation)
  • class_elem_min : Integer – 0:Integer'Last
  • class_elem_max : Integer
  • class_elem_greedy : Boolean
  • class_elem_pos : RE_Elem_AC
  • class_elem_neg : RE_Elem_AC
• REQ_CLASS (Created after translation)
  • class_min : Integer – 0:Integer'Last
  • class_max : Integer
  • class_maxORG : Integer - orginal class_max value from compilation
  • class_greedy : Boolean
  • class_pos : RangeVectorPack.RangeVector
  • class_neg : RangeVectorPack.RangeVector
• REQ_CLASS_CHAR (Exists only during translation)
  • class_char_negative : Boolean
  • class_char_value : CodePoint – no meta characters
• REQ_CLASS_RANGE (Exists only during translation)
  • class_range_negative : Boolean
  • class_range_first : CodePoint
  • class_range_last : CodePoint
• REQ_CLASS_GC (Exists only during translation)
  • class_gc_negative : Boolean
  • class_gc_value : CFix(1..2)
• REQ_CLASS_GCU (Exists only during translation)
  • class_gcu_negative : Boolean
  • class_gcu_value : CodePoint
• REQ_CLASS_SET (Exists only during translation)
  • class_set_negative : Boolean
  • class_set_value : CVar
• REQ_CLASS_OTHER (Exists only during translation)
  • class_other_negative : Boolean
  • class_other_value : CodePoint
• REQ_PALCAP
  • palcap_min : Integer – 0:Integer'Last
  • palcap_max : Integer
  • palcap_greedy : Boolean
  • palcap_up : RE_Elem_AC – null if on base line
  • palcap_down : RE_Elem_AC
  • palcap_ia: I_A - index in c4match, i.e. index from the CFix array which is searched
    
• REQ_PAL
  • pal_dummy: Boolean
  • pal_min : Integer – 0:Integer'Last
  • pal_max : Integer
  • pal_greedy : Boolean
  • pal_up : RE_Elem_AC – null if on base line
  • pal_down : RE_Elem_AC
• REQ_UPDOWN
  • updown_up : RE_Elem_AC – null if on base line
  • updown_down : RE_Elem_AC
• REQ_POS
  • pos_up : RE_Elem_AC – null if on base line
  • pos_down : RE_Elem_AC
• REQ_NEG
  • neg_up : RE_Elem_AC – null if on base line
  • neg_down : RE_Elem_AC
• REQ_NULL (Dummy)
  • null_dummy: Boolean