In Lisp, you put the "operator" first, so instead of
2 + 3 + 4
you write
(+ 2 3 4)
This is nice for associative operations like + or *, very very very slightly confusing for - and /
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You use the same style for comparisons, so instead of
2 == 3 == 4
you write
(== 2 3 4)
To support the fist "infix" syntax, you need some magic in the == operator. But the second "prefix" syntax is totally natural and you need no magic in the parser or the operator.
I knew that Lisp does this operator first thing, it's everything around this that I'm not familiar with. What does ; do? Is the => an arrow or greater than or equal to? What is t? Do I guess correctly that most-negative-fixnum is like INT_MIN?
The semicolon is Lisp syntax for comments. T is the way you write true in Lisp. Most-negative-fixnum is the most negative number Lisp can represent without promotion to bignum (so it can be int_min if int is roughly equivalent to size_t).
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You use the same style for comparisons, so instead of
you write To support the fist "infix" syntax, you need some magic in the == operator. But the second "prefix" syntax is totally natural and you need no magic in the parser or the operator.