7.9.3 The structure of parse trees

Page 214 of 800

Search internet

quote 2 + 3 end quote has the following value:

$<< r _ { p } :: i _ { p } :: d _ { p } ,, << r _ { 2 } :: i _ { 2 } :: d _ { 2 } >> ,, << r _ { 3 } :: i _ { 3 } :: d _ { 3 } >> >>$

Above, $r _ { p }$ , $i _ { p }$ , and $d _ { p }$ denote the reference, index, and debugging information, respectively, of the plus construct. Likewise, $r _ { 2 }$ , $i _ { 2 }$ , and $d _ { 2 }$ denote the reference, index, and debugging information of the 'two' construct and similarly for $r _ { 3 }$ , $i _ { 3 }$ , and $d _ { 3 }$ .

In general, the quoted version of a term has form

$<< r :: i :: d ,, t _ { 1 } ,, ... ,, t _ { n } >>$

where $t _ { 1 } ,, ... ,, t _ { n }$ are quoted versions of the subterms of the term.

The value of quote !"abc" end quote is << 0 :: !"abc" :: d >> .

Page 214 of 800

Search logiweb.eu