special forms and, or

This commit is contained in:
Pekka Laiho 2020-06-04 18:00:30 +07:00
parent 463025d43d
commit 2f6409ce72

View File

@ -14,7 +14,20 @@ class Evaller
// Handle special forms // Handle special forms
if ($ast->get(0) instanceof Symbol) { if ($ast->get(0) instanceof Symbol) {
if ($ast->get(0)->getName() == 'def') { if ($ast->get(0)->getName() == 'and') {
if ($ast->count() == 1) {
return true;
}
for ($i = 1; $i < $ast->count(); $i++) {
$value = $this->eval($ast->get($i), $env);
if ($value == false) {
return $value;
}
}
return $value;
} elseif ($ast->get(0)->getName() == 'def') {
if ($ast->count() != 3) { if ($ast->count() != 3) {
throw new MadLispException("def requires exactly 2 arguments"); throw new MadLispException("def requires exactly 2 arguments");
} }
@ -113,6 +126,19 @@ class Evaller
} }
return $this->eval($ast->get(2), $newEnv); return $this->eval($ast->get(2), $newEnv);
} elseif ($ast->get(0)->getName() == 'or') {
if ($ast->count() == 1) {
return false;
}
for ($i = 1; $i < $ast->count(); $i++) {
$value = $this->eval($ast->get($i), $env);
if ($value == true) {
return $value;
}
}
return $value;
} elseif ($ast->get(0)->getName() == 'quote') { } elseif ($ast->get(0)->getName() == 'quote') {
if ($ast->count() != 2) { if ($ast->count() != 2) {
throw new MadLispException("quote requires exactly 1 argument"); throw new MadLispException("quote requires exactly 1 argument");