np: parse: Add AST structure and initial logic

Signed-off-by: Ian Moffett <ian@osmora.org>

3 files changed, 76 insertions, 0 deletions

diff --git a/src/sys/include/np/ast.h b/src/sys/include/np/ast.h
new file mode 100644
index 0000000..9647f53
--- /dev/null
+++ b/src/sys/include/np/ast.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _NP_AST_H_
+#define _NP_AST_H_ 1
+
+#include <sys/cdefs.h>
+#include <np/lex.h>
+#include <os/np.h>
+#include <lib/ptrbox.h>
+#include <string.h>
+
+/*
+ * Represents an AST node
+ *
+ * @ident: Identifier
+ * @token: Token type
+ * @left: Left node
+ * @right: Right node
+ */
+struct ast_node {
+    char *ident;
+    tt_t token;
+    struct ast_node *left;
+    struct ast_node *right;
+};
+
+__always_inline static inline void *
+ast_alloc(struct np_work *work)
+{
+    struct ast_node *np;
+
+    np = ptrbox_alloc(sizeof(*np), work->work_mem);
+    if (np != NULL) {
+        memset(np, 0, sizeof(*np));
+    }
+    return np;
+}
+
+#endif  /* !_NP_AST_H_ */
diff --git a/src/sys/include/os/np.h b/src/sys/include/os/np.h
index 3bb2bb8..c3921cb 100644
--- a/src/sys/include/os/np.h
+++ b/src/sys/include/os/np.h
@@ -47,6 +47,7 @@
  * @source_size: Source size in bytes
  * @line_no: Current line number
  * @lex_st: Lexer state
+ * @ast_root: Parse tree
  * @ccache: Character cache (temporary store for lexer)
  */
 struct np_work {
@@ -55,6 +56,7 @@ struct np_work {
     size_t line_no;
     struct lexer_state lex_st;
     struct ptrbox *work_mem;
+    struct ast_node *ast_root;
     char ccache;
 };
 
diff --git a/src/sys/np/core/np_parse.c b/src/sys/np/core/np_parse.c
index 12732cd..63f93aa 100644
--- a/src/sys/np/core/np_parse.c
+++ b/src/sys/np/core/np_parse.c
@@ -33,6 +33,7 @@
 #include <sys/param.h>
 #include <np/lex.h>
 #include <np/parse.h>
+#include <np/ast.h>
 #include <os/np.h>
 
 #define pr_trace(fmt, ...) printf("pirho.parse: " fmt, ##__VA_ARGS__)
@@ -173,6 +174,13 @@ parse_work(struct np_work *work)
         return -EINVAL;
     }
 
+    /* Get the AST root node */
+    work->ast_root = ast_alloc(work);
+    if (work->ast_root == NULL) {
+        pr_error("failed to alloc root AST|n");
+        return -ENOMEM;
+    }
+
     while (error == 0) {
         error = lex_nom(work, &tok);
         if (error < 0) {