refactor: spread across files

lisp.h

@@ -0,0 +1,66 @@
+#ifndef LISP_H
+#define LISP_H
+
+#include "nob.h"
+
+typedef enum e_TokenKind {
+    TOKEN_KIND_PAR_LEFT,
+    TOKEN_KIND_PAR_RIGHT,
+    TOKEN_KIND_NUMBER,
+    TOKEN_KIND_SYMBOL,
+} TokenKind;
+
+typedef struct s_Token {
+    TokenKind kind;
+    Nob_String_View data;
+} Token;
+
+typedef struct s_Tokens {
+    Token *items;
+    size_t count;
+    size_t capacity;
+} Tokens;
+
+typedef enum e_NodeKind {
+    NODE_KIND_SYMBOL,
+    NODE_KIND_LIST,
+    NODE_KIND_NUMBER,
+    NODE_KIND_FUNCTION,
+} NodeKind;
+
+typedef struct s_Node Node;
+typedef struct s_Nodes Nodes;
+
+typedef Node *(*lisp_function_ptr)(Nodes *args);
+typedef struct s_LispFunction {
+    Nob_String_View name;
+    lisp_function_ptr apply;
+} LispFunction;
+
+typedef struct s_Node {
+    NodeKind kind;
+    union {
+        Nob_String_View as_symbol;
+        Nodes *as_list;
+        long long as_number;
+        LispFunction as_function;
+    };
+} Node;
+
+struct s_Nodes {
+    Node *items;
+    size_t count;
+    size_t capacity;
+};
+
+const char *token_kind_name(TokenKind kind);
+void node_print(Node node);
+
+void tokenize(Nob_String_View content, Tokens *tokens);
+Node *parse(Tokens *tokens);
+Node *eval(Node *node);
+
+// builtins
+Node *lisp_function_addition(Nodes *args);
+
+#endif // LISP_H