initial commit

src/logic/wren/vm/wren_primitive.h

@@ -0,0 +1,88 @@
+#ifndef wren_primitive_h
+#define wren_primitive_h
+
+#include "wren_vm.h"
+
+// Binds a primitive method named [name] (in Wren) implemented using C function
+// [fn] to `ObjClass` [cls].
+#define PRIMITIVE(cls, name, function) \
+    { \
+      int symbol = wrenSymbolTableEnsure(vm, \
+          &vm->methodNames, name, strlen(name)); \
+      Method method; \
+      method.type = METHOD_PRIMITIVE; \
+      method.as.primitive = prim_##function; \
+      wrenBindMethod(vm, cls, symbol, method); \
+    }
+
+// Defines a primitive method whose C function name is [name]. This abstracts
+// the actual type signature of a primitive function and makes it clear which C
+// functions are invoked as primitives.
+#define DEF_PRIMITIVE(name) \
+    static bool prim_##name(WrenVM* vm, Value* args)
+
+#define RETURN_VAL(value)   do { args[0] = value; return true; } while (0)
+
+#define RETURN_OBJ(obj)     RETURN_VAL(OBJ_VAL(obj))
+#define RETURN_BOOL(value)  RETURN_VAL(BOOL_VAL(value))
+#define RETURN_FALSE        RETURN_VAL(FALSE_VAL)
+#define RETURN_NULL         RETURN_VAL(NULL_VAL)
+#define RETURN_NUM(value)   RETURN_VAL(NUM_VAL(value))
+#define RETURN_TRUE         RETURN_VAL(TRUE_VAL)
+
+#define RETURN_ERROR(msg) \
+    do { \
+      vm->fiber->error = wrenNewStringLength(vm, msg, sizeof(msg) - 1); \
+      return false; \
+    } while (0);
+
+#define RETURN_ERROR_FMT(msg, arg) \
+    do { \
+      vm->fiber->error = wrenStringFormat(vm, msg, arg); \
+      return false; \
+    } while (0);
+
+// Validates that the given [arg] is a function. Returns true if it is. If not,
+// reports an error and returns false.
+bool validateFn(WrenVM* vm, Value arg, const char* argName);
+
+// Validates that the given [arg] is a Num. Returns true if it is. If not,
+// reports an error and returns false.
+bool validateNum(WrenVM* vm, Value arg, const char* argName);
+
+// Validates that [value] is an integer. Returns true if it is. If not, reports
+// an error and returns false.
+bool validateIntValue(WrenVM* vm, double value, const char* argName);
+
+// Validates that the given [arg] is an integer. Returns true if it is. If not,
+// reports an error and returns false.
+bool validateInt(WrenVM* vm, Value arg, const char* argName);
+
+// Validates that [arg] is a valid object for use as a map key. Returns true if
+// it is. If not, reports an error and returns false.
+bool validateKey(WrenVM* vm, Value arg);
+
+// Validates that the argument at [argIndex] is an integer within `[0, count)`.
+// Also allows negative indices which map backwards from the end. Returns the
+// valid positive index value. If invalid, reports an error and returns
+// `UINT32_MAX`.
+uint32_t validateIndex(WrenVM* vm, Value arg, uint32_t count,
+                       const char* argName);
+
+// Validates that the given [arg] is a String. Returns true if it is. If not,
+// reports an error and returns false.
+bool validateString(WrenVM* vm, Value arg, const char* argName);
+
+// Given a [range] and the [length] of the object being operated on, determines
+// the series of elements that should be chosen from the underlying object.
+// Handles ranges that count backwards from the end as well as negative ranges.
+//
+// Returns the index from which the range should start or `UINT32_MAX` if the
+// range is invalid. After calling, [length] will be updated with the number of
+// elements in the resulting sequence. [step] will be direction that the range
+// is going: `1` if the range is increasing from the start index or `-1` if the
+// range is decreasing.
+uint32_t calculateRange(WrenVM* vm, ObjRange* range, uint32_t* length,
+                        int* step);
+
+#endif