1 files changed, 55 insertions, 0 deletions

diff --git a/include/A.h b/include/A.h
new file mode 100644
index 0000000..9c2db23
--- /dev/null
+++ b/include/A.h
@@ -0,0 +1,55 @@
+/* types, of pointers to corresponding structs */
+typedef struct A_stm_ *A_stm;
+typedef struct A_exp_ *A_exp;
+typedef struct A_expList_ *A_expList;
+
+/* binary operation */
+typedef enum { A_plus, A_minus, A_times, A_div } A_binop;
+
+/* statement */
+struct A_stm_ {
+        /* types: compound, assign, print */
+        enum { A_compoundStm, A_assignStm, A_printStm } type;
+        union {
+                struct { A_stm stm1, stm2; }    compound;
+                struct { char *id; A_exp exp; } assign;
+                struct { A_expList exps; }              print;
+        } u;
+};
+
+/* statement constrctor functions */
+A_stm A_CompoundStm     ( A_stm stm1, A_stm stm2 );
+A_stm A_AssignStm       ( char *id, A_exp exp );
+A_stm A_PrintStm        ( A_expList exps );
+
+/* expression */
+struct A_exp_ {
+        /* types: id, number, operation, sequence */
+        enum { A_idExp, A_numExp, A_opExp, A_eseqExp } type;
+        union {
+                        char *id;
+                        int num;
+                        struct { A_exp exp1; A_binop op; A_exp exp2; } op;
+                        struct { A_stm stm; A_exp exp; } eseq;
+        } u;
+};
+
+/* expression constructor functions */
+A_exp A_IdExp   ( char *id );
+A_exp A_NumExp  ( int num );
+A_exp A_OpExp   ( A_exp exp1, A_binop op, A_exp exp2 );
+A_exp A_EseqExp ( A_stm stm, A_exp exp );
+
+/* expression list */
+struct A_expList_ {
+        /* types: pair, last */
+        enum { A_pairExpList, A_lastExpList } type;
+        union {
+                struct { A_exp head; A_expList tail; } pair;
+                A_exp last;
+        } u;
+};
+
+/* expression list constructor functions */
+A_expList A_PairExpList (A_exp head, A_expList tail);
+A_expList A_LastExplist (A_exp last);