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author | Kaz Kylheku <kaz@kylheku.com> | 2019-09-20 07:47:16 -0700 |
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committer | Kaz Kylheku <kaz@kylheku.com> | 2019-09-20 07:47:16 -0700 |
commit | 6aececdf6040e26fef0bb634e832883943a4f1d0 (patch) | |
tree | de34f9fd89a67ad6925ab4b0da3b575ab3527b4c | |
parent | 7a9ab728565c650e0631744e79e7e8a77f57e347 (diff) | |
download | txr-6aececdf6040e26fef0bb634e832883943a4f1d0.tar.gz txr-6aececdf6040e26fef0bb634e832883943a4f1d0.tar.bz2 txr-6aececdf6040e26fef0bb634e832883943a4f1d0.zip |
equal: reduce type checking for conses.
* lib.c (equal): Since we have switched on the type of the
left and right argument, we can access the object directly
instead of going through car and cdr. Except that for a lazy
conses, we need at least one such access to force the object
first.
-rw-r--r-- | lib.c | 25 |
1 files changed, 22 insertions, 3 deletions
@@ -2681,12 +2681,31 @@ val equal(val left, val right) case NUM: break; case CONS: + switch (type(right)) { + case CONS: + if (equal(left->c.car, right->c.car) && equal(left->c.cdr, right->c.cdr)) + return t; + return nil; + case LCONS: + if (equal(left->c.car, car(right)) && equal(left->c.cdr, right->c.cdr)) + return t; + return nil; + default: + break; + } + return nil; case LCONS: - if (type(right) == CONS || type(right) == LCONS) - { - if (equal(car(left), car(right)) && equal(cdr(left), cdr(right))) + switch (type(right)) { + case CONS: + if (equal(car(left), right->c.car) && equal(left->c.cdr, right->c.cdr)) return t; return nil; + case LCONS: + if (equal(car(left), car(right)) && equal(left->c.cdr, right->c.cdr)) + return t; + return nil; + default: + break; } break; case LIT: |