Syntax Directed Translation
Syntax Directed Translation
Syntax Directed Translation
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Construction of <strong>Syntax</strong> Trees (ASU Ch 5.2 Ex 5.7)<br />
• Intermediate representation<br />
• de-couples translation from<br />
parsing<br />
• condensed form of parse tree<br />
• examples<br />
3<br />
*<br />
3*5+4 if B then S 1 else S 2<br />
+ if-then-else<br />
5<br />
4<br />
B S 1 S 2<br />
• <strong>Syntax</strong> trees for expressions<br />
(cf translation to post-fix form)<br />
• operations<br />
– mknode(op left, right)<br />
– mkleaf(id, entry)<br />
– mkleaf(num, entry)<br />
• e.g. a-4+c<br />
p1 := mkleaf(id, entry-a)<br />
p2 := mkleaf(num, 4)<br />
p3 := mknode(‘-’, p1, p2)<br />
p4 := mkleaf(id, entry-c)<br />
p5 := mknode(‘+’, p3, p4)<br />
see ASU Fig 5.8 for syntax tree<br />
10<br />
14/10/2014 DFR - CC - SDT
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