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| author | Kartik K. Agaram <vc@akkartik.com> | 2021-06-11 21:46:55 -0700 |
|---|---|---|
| committer | Kartik K. Agaram <vc@akkartik.com> | 2021-06-11 21:46:59 -0700 |
| commit | 952fb9a677de3f59aec09df3377858525ca03705 (patch) | |
| tree | e31b5514df856cd2318236085fb579b2ff09a194 | |
| parent | 0dc4f9c62bf26b373284e7d27aa41c500c8bd16a (diff) | |
| download | mu-952fb9a677de3f59aec09df3377858525ca03705.tar.gz | |
car/cdr of nil is now nil
| -rw-r--r-- | shell/primitives.mu | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/shell/primitives.mu b/shell/primitives.mu index a8f22141..59fb86cf 100644 --- a/shell/primitives.mu +++ b/shell/primitives.mu @@ -774,7 +774,7 @@ fn apply-car _args-ah: (addr handle cell), out: (addr handle cell), trace: (addr return } # args->left - var first-ah/eax: (addr handle cell) <- get args, left + var first-ah/edx: (addr handle cell) <- get args, left var first/eax: (addr cell) <- lookup *first-ah var first-type/ecx: (addr int) <- get first, type compare *first-type, 0/pair @@ -783,6 +783,14 @@ fn apply-car _args-ah: (addr handle cell), out: (addr handle cell), trace: (addr error trace, "arg for car is not a pair" return } + # nil? return nil + { + var nil?/eax: boolean <- nil? first + compare nil?, 0/false + break-if-= + copy-object first-ah, out + return + } # car var result/eax: (addr handle cell) <- get first, left copy-object result, out @@ -802,7 +810,7 @@ fn apply-cdr _args-ah: (addr handle cell), out: (addr handle cell), trace: (addr return } # args->left - var first-ah/eax: (addr handle cell) <- get args, left + var first-ah/edx: (addr handle cell) <- get args, left var first/eax: (addr cell) <- lookup *first-ah var first-type/ecx: (addr int) <- get first, type compare *first-type, 0/pair @@ -811,6 +819,14 @@ fn apply-cdr _args-ah: (addr handle cell), out: (addr handle cell), trace: (addr error trace, "arg for cdr is not a pair" return } + # nil? return nil + { + var nil?/eax: boolean <- nil? first + compare nil?, 0/false + break-if-= + copy-object first-ah, out + return + } # cdr var result/eax: (addr handle cell) <- get first, right copy-object result, out |