support argument for env

This commit is contained in:
Pekka Laiho 2020-06-04 17:36:01 +07:00
parent 90654396b9
commit 8ec2ad4596

View File

@ -12,7 +12,7 @@ class Evaller
return $ast;
}
// Handle special keywords
// Handle special forms
if ($ast->get(0) instanceof Symbol) {
if ($ast->get(0)->getName() == 'def') {
if ($ast->count() != 3) {
@ -31,12 +31,20 @@ class Evaller
}
for ($i = 1; $i < $ast->count(); $i++) {
$value = $this->evalAst($ast->get($i), $env);
$value = $this->eval($ast->get($i), $env);
}
return $value;
} elseif ($ast->get(0)->getName() == 'env') {
return $env;
if ($ast->count() >= 2) {
if (!($ast->get(1) instanceof Symbol)) {
throw new MadLispException("first argument to env is not symbol");
}
return $env->get($ast->get(1)->getName());
} else {
return $env;
}
} elseif ($ast->get(0)->getName() == 'fn') {
if ($ast->count() != 3) {
throw new MadLispException("fn requires exactly 2 arguments");
@ -120,8 +128,9 @@ class Evaller
// Call first argument as function
$func = $ast->get(0);
if (!($func instanceof Func)) {
throw new MadLispException("first item of list is not function");
throw new MadLispException("eval: first item of list is not function");
}
$args = array_slice($ast->getData(), 1);
return $func->call($args);
}