diff options
| -rw-r--r-- | src/CoreBindings.kt | 29 | ||||
| -rw-r--r-- | test/res/test.lisp | 3 |
2 files changed, 32 insertions, 0 deletions
diff --git a/src/CoreBindings.kt b/src/CoreBindings.kt index aa40366..cf4fc50 100644 --- a/src/CoreBindings.kt +++ b/src/CoreBindings.kt @@ -16,6 +16,32 @@ object CoreBindings { return@externalRawCall stackFrame.setValueLocal(name.label, context.resolveValue(stackFrame, value)) } + private fun isTruthy(data: LispData): Boolean? { + if (data == trueValue) return true + if (data == falseValue) return false + return null + } + + val trueValue = LispData.Atom("true") + val falseValue = LispData.Atom("false") + + val ifFun = LispData.externalRawCall { context, callsite, stackFrame, args -> + if (args.size != 3) { + return@externalRawCall context.reportError("if requires 3 arguments", callsite) + } + val (cond, ifTrue, ifFalse) = args + + val c = isTruthy(context.resolveValue(stackFrame, cond)) + if (c == null) { + return@externalRawCall context.reportError("Non boolean value $c used as condition for if", cond) + } + if (c) { + return@externalRawCall context.resolveValue(stackFrame, ifTrue) + } else { + return@externalRawCall context.resolveValue(stackFrame, ifFalse) + } + } + val pure = LispData.externalCall { args, reportError -> return@externalCall args.singleOrNull()?.let { value -> LispData.externalCall { args, reportError -> @@ -156,6 +182,9 @@ object CoreBindings { } fun offerAllTo(bindings: StackFrame) { + bindings.setValueLocal("true", trueValue) + bindings.setValueLocal("false", falseValue) + bindings.setValueLocal("if", ifFun) bindings.setValueLocal("nil", nil) bindings.setValueLocal("def", def) bindings.setValueLocal("pure", pure) diff --git a/test/res/test.lisp b/test/res/test.lisp index 79c96dc..edadffd 100644 --- a/test/res/test.lisp +++ b/test/res/test.lisp @@ -3,6 +3,9 @@ (myfun :myfunworks) ((lambda (a) (debuglog a)) :atom) (debuglog a) +(defun testsomething (c) (debuglog (if c "truthy value" "falsey value"))) +(testsomething true) +(testsomething false) (defun testlog (a ...) (seq (debuglog "a" a) (debuglog "..." ...))) |