1 files changed, 125 insertions, 0 deletions
diff --git a/sexp.h b/sexp.h
new file mode 100644
index 0000000..ce47362
--- /dev/null
+++ b/sexp.h
@@ -0,0 +1,125 @@
+#ifndef BAMBOO_LISP_SEXP_H_
+#define BAMBOO_LISP_SEXP_H_
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <algds/vec.h>
+
+struct sexp;
+typedef struct sexp SExp;
+
+typedef struct {
+    int32_t idx;
+} SExpRef;
+
+typedef struct {
+    SExpRef car;
+    SExpRef cdr;
+    SExpRef filename;
+    int32_t line;
+} SExpPair;
+
+typedef struct {
+    SExpRef args;
+    SExpRef body;
+    SExpRef env;
+} SExpFunc;
+
+struct interp;
+typedef struct interp Interp;
+typedef SExpRef (*LispUserFunc)(Interp *interp, SExpRef args);
+typedef SExpRef (*LispPrimitive)(Interp *interp, SExpRef sexp, bool istail);
+
+typedef struct {
+    SExpRef args;
+    SExpRef body;
+} SExpMacro;
+
+typedef struct {
+    SExpRef parent;
+    SExpRef bindings;
+} SExpEnv;
+
+typedef struct {
+    SExpRef name;
+    SExpRef value;
+    SExpRef func;
+    SExpRef next;
+} SExpBinding;
+
+typedef struct {
+    SExpRef fn;
+    SExpRef args;
+} SExpTailcall;
+
+typedef enum {
+    kEmptySExp,
+    kIntegerSExp,
+    kRealSExp,
+    kBooleanSExp,
+    kNilSExp,
+    kCharSExp,
+    kStringSExp,
+    kSymbolSExp,
+    kUserDataSExp,
+    kPairSExp,
+    kFuncSExp,
+    kUserFuncSExp,
+    kPrimitiveSExp,
+    kEnvSExp,
+    kBindingSExp,
+    kMacroSExp,
+    kErrSignal,
+    kReturnSignal,
+    kBreakSignal,
+    kContinueSignal,
+    kTailcallSExp,
+    kExceptionSignal,
+} SExpType;
+
+VECTOR_DEF(SExpRef);
+
+typedef SExp *SExpPtr;
+VECTOR_DEF(SExpPtr);
+
+typedef struct {
+    const char *type;
+    void (*free)(void *self);
+    void (*gcmark)(Interp *interp, SExpPtrVector *gcstack, void *self);
+} LispUserdataMeta;
+
+struct sexp {
+    bool marked;
+    SExpType type;
+    union {
+        int64_t integer;
+        double real;
+        bool boolean;
+        char character;
+        const char *str;
+        struct {
+            void *userdata;
+            LispUserdataMeta *userdata_meta;
+        };
+        SExpPair pair;
+        SExpFunc func;
+        LispUserFunc userfunc;
+        LispPrimitive primitive;
+        SExpEnv env;
+        SExpBinding binding;
+        SExpMacro macro;
+        SExpRef ret;
+        SExpTailcall tailcall;
+    };
+};
+
+
+void SExp_show(SExp self, FILE* fp);
+void SExpRef_show(SExpRef self, FILE* fp);
+void SExpPtr_show(SExpPtr self, FILE* fp);
+
+VECTOR_DEF(SExp);
+
+#endif
+