Mercurial > hg-old > index.cgi
comparison src/expr.h @ 17:df0c4a46af8f
Started adding expression handling infrastructure
author | lost |
---|---|
date | Thu, 01 Jan 2009 02:26:26 +0000 |
parents | 1f598d89b9b0 |
children | 218aabbc3b1a |
comparison
equal
deleted
inserted
replaced
16:4f14eae64d38 | 17:df0c4a46af8f |
---|---|
23 */ | 23 */ |
24 | 24 |
25 #ifndef __expr_h_seen__ | 25 #ifndef __expr_h_seen__ |
26 #define __expr_h_seen__ | 26 #define __expr_h_seen__ |
27 | 27 |
28 #include "lwval.h" | |
29 | |
30 #ifndef __expr_c_seen__ | 28 #ifndef __expr_c_seen__ |
31 #define __expr_E__ extern | 29 #define __expr_E__ extern |
32 #else | 30 #else |
33 #define __expr_E__ | 31 #define __expr_E__ |
34 #endif | 32 #endif |
35 | 33 |
36 // parse an expression | 34 // term types |
37 __expr_E__ LWVAL *lwasm_parse_expr(char **ptr); | 35 #define LWASM_TERM_NONE 0 |
36 #define LWASM_TERM_OPER 1 // an operator | |
37 #define LWASM_TERM_INT 2 // 32 bit signed integer | |
38 #define LWASM_TERM_SYM 3 // symbol reference | |
38 | 39 |
39 // attempt to evaluate/simplify expression | 40 // operator types |
40 __expr_E__ int lwasm_eval_expr(LWVAL *expr); | 41 #define LWASM_OPER_NONE 0 |
42 #define LWASM_OPER_PLUS 1 // + | |
43 #define LWASM_OPER_MINUS 2 // - | |
44 #define LWASM_OPER_TIMES 3 // * | |
45 #define LWASM_OPER_DIVIDE 4 // / | |
46 #define LWASM_OPER_MOD 5 // % | |
47 #define LWASM_OPER_INTDIV 6 // \ | |
48 #define LWASM_OPER_BWAND 7 // bitwise AND | |
49 #define LWASM_OPER_BWOR 8 // bitwise OR | |
50 #define LWASM_OPER_BWXOR 9 // bitwise XOR | |
51 #define LWASM_OPER_AND 10 // boolean AND | |
52 #define LWASM_OPER_OR 11 // boolean OR | |
53 #define LWASM_OPER_NEG 12 // unary negation (2's complement) | |
54 #define LWASM_OPER_COM 13 // unary 1's complement | |
55 | |
56 | |
57 // term structure | |
58 typedef struct lwasm_expr_term_s | |
59 { | |
60 int term_type; // type of term (see above) | |
61 char *symbol; // name of a symbol | |
62 int value; // value of the term (int) or operator number (OPER) | |
63 } lwasm_expr_term_t; | |
64 | |
65 // type for an expression evaluation stack | |
66 typedef struct lwasm_expr_stack_node_s lwasm_expr_stack_node_t; | |
67 struct lwasm_expr_stack_node_s | |
68 { | |
69 lwasm_expr_term_t *term; | |
70 lwasm_expr_stack_node_t *prev; | |
71 lwasm_expr_stack_node_t *next; | |
72 }; | |
73 | |
74 typedef struct lwasm_expr_stack_s | |
75 { | |
76 lwasm_expr_stack_node_t *head; | |
77 lwasm_expr_stack_node_t *tail; | |
78 } lwasm_expr_stack_t; | |
79 | |
80 __expr_E__ void lwasm_expr_term_free(lwasm_expr_term_t *t); | |
81 __expr_E__ lwasm_expr_term_t *lwasm_expr_term_create_oper(int oper); | |
82 __expr_E__ lwasm_expr_term_t *lwasm_expr_term_create_sym(char *sym); | |
83 __expr_E__ lwasm_expr_term_t *lwasm_expr_term_create_int(int val); | |
84 __expr_E__ lwasm_expr_term_t *lwasm_expr_term_dup(lwasm_expr_term_t *t); | |
85 | |
86 __expr_E__ void lwasm_expr_stack_free(lwasm_expr_stack_t *s); | |
87 __expr_E__ lwasm_expr_stack_t *lwasm_expr_stack_create(void); | |
88 | |
89 __expr_E__ void lwasm_expr_stack_push(lwasm_expr_stack_t *s, lwasm_expr_term_t *t); | |
90 __expr_E__ lwasm_expr_term_t *lwasm_expr_stack_pop(lwasm_expr_stack_t *s); | |
41 | 91 |
42 #undef __expr_E__ | 92 #undef __expr_E__ |
43 | 93 |
44 #endif // __expr_h_seen__ | 94 #endif // __expr_h_seen__ |