feat: add fields, path, list API

.gitignore

@@ -5,3 +5,5 @@
 /libcue.h
 /libcue.so
 /libcue.a
+
+/.idea/

cue.h

@@ -101,6 +101,8 @@ char*	cue_error_string(cue_error);
 
 cue_error	cue_compile_string(cue_ctx, char*, cue_bopt*, cue_value*);
 cue_error	cue_compile_bytes(cue_ctx, void*, size_t, cue_bopt*, cue_value*);
+cue_value*  cue_fields(cue_value, size_t*);
+cue_value*	cue_list(cue_value, size_t*);
 cue_value	cue_top(cue_ctx);
 cue_value	cue_bottom(cue_ctx);
 cue_value	cue_unify(cue_value, cue_value);
@@ -112,6 +114,7 @@ cue_value	cue_from_bool(cue_ctx, bool);
 cue_value	cue_from_double(cue_ctx, double);
 cue_value	cue_from_string(cue_ctx, char*);
 cue_value	cue_from_bytes(cue_ctx, void*, size_t);
+cue_value   cue_from_list(cue_ctx, cue_value*, size_t);
 cue_error	cue_dec_int64(cue_value, int64_t*);
 cue_error	cue_dec_uint64(cue_value, uint64_t*);
 cue_error	cue_dec_bool(cue_value, bool*);
@@ -124,6 +127,7 @@ cue_value	cue_default(cue_value, bool*);
 cue_kind	cue_concrete_kind(cue_value);
 cue_kind	cue_incomplete_kind(cue_value);
 cue_error	cue_value_error(cue_value);
+char*	cue_path(cue_value);
 bool	cue_is_equal(cue_value, cue_value);
 
 cue_bopt	cue_filename(char*);

fields.go

@@ -0,0 +1,52 @@
+// Copyright 2024 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+/*
+#include <stdint.h>
+#include <stdbool.h>
+#include "cue.h"
+*/
+import "C"
+
+import (
+	"cuelang.org/go/cue"
+)
+
+//export cue_fields
+func cue_fields(v C.cue_value, count *C.size_t) *C.cue_value {
+	iter, err := cueValue(v).Fields()
+	if err != nil {
+		return nil
+	}
+
+	var fields []cue.Value
+	for iter.Next() {
+		fields = append(fields, iter.Value())
+	}
+
+	*count = C.size_t(len(fields))
+
+	if len(fields) == 0 {
+		return nil
+	}
+
+	s, ptr := calloc[C.cue_value](len(fields), C.sizeof_cue_value)
+	for i, f := range fields {
+		s[i] = cueValueHandle(f)
+	}
+
+	return ptr
+}

value.go

@@ -125,6 +125,16 @@ func cue_from_bytes(ctx C.cue_ctx, buf unsafe.Pointer, len C.size_t) C.cue_value
 	return cueValueHandle(val)
 }
 
+//export cue_from_list
+func cue_from_list(ctx C.cue_ctx, values *C.cue_value, count C.size_t) C.cue_value {
+	var v []cue.Value
+	for _, val := range unsafe.Slice(values, count) {
+		v = append(v, cueValue(val))
+	}
+	nl := cueContext(ctx).NewList(v...)
+	return cueValueHandle(nl)
+}
+
 //export cue_dec_int64
 func cue_dec_int64(v C.cue_value, res *C.int64_t) C.cue_error {
 	n, err := cueValue(v).Int64()
@@ -286,3 +296,35 @@ func cue_value_error(v C.cue_value) C.cue_error {
 	}
 	return 0
 }
+
+//export cue_path
+func cue_path(v C.cue_value) *C.char {
+	label := cueValue(v).Path().String()
+	return C.CString(label)
+}
+
+//export cue_list
+func cue_list(v C.cue_value, count *C.size_t) *C.cue_value {
+	iter, err := cueValue(v).List()
+	if err != nil {
+		return nil
+	}
+
+	var elements []cue.Value
+	for iter.Next() {
+		elements = append(elements, iter.Value())
+	}
+
+	*count = C.size_t(len(elements))
+
+	if len(elements) == 0 {
+		return nil
+	}
+
+	s, ptr := calloc[C.cue_value](len(elements), C.sizeof_cue_value)
+	for i, elem := range elements {
+		s[i] = cueValueHandle(elem)
+	}
+
+	return ptr
+}