Principles of Programming Languages

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Principles of ProgrammingLanguages

• Lecture 02
• Language Design Criteria

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Criteria, FOIL 1-7
3
a ( f(a,g(a)) / g(a) )

a
/
a
g(x) by name xga2
f
g
f(x,y) by value afx1
a
g
a
main a0 print expr
a
4
(a) Eval denom. 1st, then numer. L-R
g(x) by name xga2

8
f(x,y) by value afx1
a3
a
/
a
main a0 print expr
6
7
f3 a3
g2 a2
f
g
1
5
g4 a4
a0
a2
g
a
2
a
4
0
a2
a
3
5
(b) Eval standard topological sort (L-R)
g(x) by name xga2

8
f(x,y) by value afx1
a0
a
/
a
main a0 print expr
7
0
f1 a1
g3 a3
f
g
6
4
g2 a2
a1
a0
g
a
1
a
3
5
a0
a
(c) Other possible results (11 total)
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