1 |
/* printf */ |
/* printf, sscanf, fgets, fprintf */ |
2 |
#include <stdio.h> |
#include <stdio.h> |
3 |
/* EXIT_SUCCESS */ |
/* exit, EXIT_SUCCESS, malloc, free */ |
4 |
#include <stdlib.h> |
#include <stdlib.h> |
5 |
/* NULL */ |
/* NULL */ |
6 |
#include <stddef.h> |
#include <stddef.h> |
7 |
/* dlopen, dlsym, dlerror */ |
/* dlopen, dlsym, dlerror */ |
8 |
#include <dlfcn.h> |
#include <dlfcn.h> |
9 |
/* assert */ |
/* strcmp, strcpy, strlen, strcat, strdup */ |
10 |
#include <assert.h> |
#include <string.h> |
11 |
|
|
12 |
#define HASHTBLSIZE 65536 |
#define HASHTBLSIZE 65536 |
13 |
|
|
57 |
stackitem *head; /* Head of the stack */ |
stackitem *head; /* Head of the stack */ |
58 |
hashtbl symbols; /* Hash table of all variable bindings */ |
hashtbl symbols; /* Hash table of all variable bindings */ |
59 |
int err; /* Error flag */ |
int err; /* Error flag */ |
60 |
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int non_eval_flag; |
61 |
} environment; |
} environment; |
62 |
|
|
63 |
/* A type for pointers to external functions */ |
/* A type for pointers to external functions */ |
67 |
/* Initialize a newly created environment */ |
/* Initialize a newly created environment */ |
68 |
void init_env(environment *env) |
void init_env(environment *env) |
69 |
{ |
{ |
70 |
long i; |
int i; |
71 |
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|
72 |
env->err=0; |
env->err= 0; |
73 |
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env->non_eval_flag= 0; |
74 |
for(i= 0; i<HASHTBLSIZE; i++) |
for(i= 0; i<HASHTBLSIZE; i++) |
75 |
env->symbols[i]= NULL; |
env->symbols[i]= NULL; |
76 |
} |
} |
77 |
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|
78 |
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void printerr(const char* in_string) { |
79 |
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fprintf(stderr, "Err: %s\n", in_string); |
80 |
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} |
81 |
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82 |
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/* Throw away a value */ |
83 |
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void free_val(value *val){ |
84 |
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stackitem *item, *temp; |
85 |
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|
86 |
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val->refcount--; /* Decrease the reference count */ |
87 |
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if(val->refcount == 0){ |
88 |
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switch (val->type){ /* and free the contents if necessary */ |
89 |
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case string: |
90 |
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free(val->content.ptr); |
91 |
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break; |
92 |
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case list: /* lists needs to be freed recursively */ |
93 |
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item=val->content.ptr; |
94 |
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while(item != NULL) { /* for all stack items */ |
95 |
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free_val(item->item); /* free the value */ |
96 |
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temp=item->next; /* save next ptr */ |
97 |
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free(item); /* free the stackitem */ |
98 |
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item=temp; /* go to next stackitem */ |
99 |
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} |
100 |
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free(val); /* Free the actual list value */ |
101 |
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break; |
102 |
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case integer: |
103 |
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case func: |
104 |
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case symb: |
105 |
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break; |
106 |
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} |
107 |
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} |
108 |
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} |
109 |
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110 |
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/* Discard the top element of the stack. */ |
111 |
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extern void toss(environment *env) |
112 |
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{ |
113 |
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stackitem *temp= env->head; |
114 |
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|
115 |
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if((env->head)==NULL) { |
116 |
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printerr("Too Few Arguments"); |
117 |
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env->err=1; |
118 |
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return; |
119 |
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} |
120 |
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121 |
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free_val(env->head->item); /* Free the value */ |
122 |
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env->head= env->head->next; /* Remove the top stack item */ |
123 |
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free(temp); /* Free the old top stack item */ |
124 |
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} |
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126 |
/* Returns a pointer to a pointer to an element in the hash table. */ |
/* Returns a pointer to a pointer to an element in the hash table. */ |
127 |
symbol **hash(hashtbl in_hashtbl, const char *in_string) |
symbol **hash(hashtbl in_hashtbl, const char *in_string) |
128 |
{ |
{ |
129 |
long i= 0; |
int i= 0; |
130 |
unsigned long out_hash= 0; |
unsigned int out_hash= 0; |
131 |
char key= '\0'; |
char key= '\0'; |
132 |
symbol **position; |
symbol **position; |
133 |
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197 |
push(stack_head, new_item); |
push(stack_head, new_item); |
198 |
} |
} |
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200 |
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/* Mangle a symbol name to a valid C identifier name */ |
201 |
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char *mangle_str(const char *old_string){ |
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char validchars[] |
203 |
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="0123456789abcdef"; |
204 |
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char *new_string, *current; |
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206 |
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new_string=malloc((strlen(old_string)*2)+4); |
207 |
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strcpy(new_string, "sx_"); /* Stack eXternal */ |
208 |
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current=new_string+3; |
209 |
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while(old_string[0] != '\0'){ |
210 |
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current[0]=validchars[(unsigned char)(old_string[0])/16]; |
211 |
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current[1]=validchars[(unsigned char)(old_string[0])%16]; |
212 |
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current+=2; |
213 |
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old_string++; |
214 |
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} |
215 |
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current[0]='\0'; |
216 |
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217 |
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return new_string; /* The caller must free() it */ |
218 |
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} |
219 |
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220 |
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extern void mangle(environment *env){ |
221 |
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value *new_value; |
222 |
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char *new_string; |
223 |
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224 |
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if((env->head)==NULL) { |
225 |
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printerr("Too Few Arguments"); |
226 |
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env->err=1; |
227 |
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return; |
228 |
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} |
229 |
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230 |
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if(env->head->item->type!=string) { |
231 |
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printerr("Bad Argument Type"); |
232 |
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env->err=2; |
233 |
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return; |
234 |
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} |
235 |
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236 |
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new_string= mangle_str((const char *)(env->head->item->content.ptr)); |
237 |
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238 |
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toss(env); |
239 |
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if(env->err) return; |
240 |
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241 |
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new_value= malloc(sizeof(value)); |
242 |
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new_value->content.ptr= new_string; |
243 |
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new_value->type= string; |
244 |
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new_value->refcount=1; |
245 |
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246 |
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push_val(&(env->head), new_value); |
247 |
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} |
248 |
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|
249 |
/* Push a symbol onto the stack. */ |
/* Push a symbol onto the stack. */ |
250 |
void push_sym(environment *env, const char *in_string) |
void push_sym(environment *env, const char *in_string) |
251 |
{ |
{ |
260 |
void *funcptr; /* A function pointer */ |
void *funcptr; /* A function pointer */ |
261 |
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|
262 |
static void *handle= NULL; /* Dynamic linker handle */ |
static void *handle= NULL; /* Dynamic linker handle */ |
263 |
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const char *dlerr; /* Dynamic linker error */ |
264 |
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char *mangled; /* Mangled function name */ |
265 |
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|
266 |
/* Create a new stack item containing a new value */ |
/* Create a new stack item containing a new value */ |
267 |
new_item= malloc(sizeof(stackitem)); |
new_item= malloc(sizeof(stackitem)); |
294 |
handle= dlopen(NULL, RTLD_LAZY); |
handle= dlopen(NULL, RTLD_LAZY); |
295 |
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|
296 |
funcptr= dlsym(handle, in_string); /* Get function pointer */ |
funcptr= dlsym(handle, in_string); /* Get function pointer */ |
297 |
if(dlerror()==NULL) { /* If a function was found */ |
dlerr=dlerror(); |
298 |
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if(dlerr != NULL) { /* If no function was found */ |
299 |
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mangled=mangle_str(in_string); |
300 |
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funcptr= dlsym(handle, mangled); /* try mangling it */ |
301 |
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free(mangled); |
302 |
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dlerr=dlerror(); |
303 |
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} |
304 |
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if(dlerr==NULL) { /* If a function was found */ |
305 |
new_fvalue= malloc(sizeof(value)); /* Create a new value */ |
new_fvalue= malloc(sizeof(value)); /* Create a new value */ |
306 |
new_fvalue->type=func; /* The new value is a function pointer */ |
new_fvalue->type=func; /* The new value is a function pointer */ |
307 |
new_fvalue->content.ptr=funcptr; /* Store function pointer */ |
new_fvalue->content.ptr=funcptr; /* Store function pointer */ |
313 |
push(&(env->head), new_item); |
push(&(env->head), new_item); |
314 |
} |
} |
315 |
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void printerr(const char* in_string) { |
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fprintf(stderr, "Err: %s\n", in_string); |
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} |
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/* Throw away a value */ |
|
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void free_val(value *val){ |
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stackitem *item, *temp; |
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val->refcount--; /* Decrease the reference count */ |
|
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if(val->refcount == 0){ |
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switch (val->type){ /* and free the contents if necessary */ |
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case string: |
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free(val->content.ptr); |
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break; |
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case list: /* lists needs to be freed recursively */ |
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item=val->content.ptr; |
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while(item != NULL) { /* for all stack items */ |
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free_val(item->item); /* free the value */ |
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temp=item->next; /* save next ptr */ |
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free(item); /* free the stackitem */ |
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item=temp; /* go to next stackitem */ |
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} |
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free(val); /* Free the actual list value */ |
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break; |
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default: |
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break; |
|
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} |
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} |
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} |
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/* Discard the top element of the stack. */ |
|
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extern void toss(environment *env) |
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{ |
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stackitem *temp= env->head; |
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if((env->head)==NULL) { |
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printerr("Too Few Arguments"); |
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env->err=1; |
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return; |
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} |
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free_val(env->head->item); /* Free the value */ |
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env->head= env->head->next; /* Remove the top stack item */ |
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free(temp); /* Free the old top stack item */ |
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} |
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316 |
/* Print newline. */ |
/* Print newline. */ |
317 |
extern void nl() |
extern void nl() |
318 |
{ |
{ |
363 |
printf("\"%s\"", (char*)stack_head->item->content.ptr); |
printf("\"%s\"", (char*)stack_head->item->content.ptr); |
364 |
break; |
break; |
365 |
case symb: |
case symb: |
366 |
printf("'%s'", ((symbol *)(stack_head->item->content.ptr))->id); |
printf("%s", ((symbol *)(stack_head->item->content.ptr))->id); |
367 |
break; |
break; |
368 |
case func: |
case func: |
369 |
printf("#<function %p>", (funcp)(stack_head->item->content.ptr)); |
printf("#<function %p>", (funcp)(stack_head->item->content.ptr)); |
377 |
printf(" "); |
printf(" "); |
378 |
stack_head=stack_head->next; |
stack_head=stack_head->next; |
379 |
} |
} |
380 |
printf("] "); |
printf("]"); |
381 |
break; |
break; |
382 |
default: |
default: |
383 |
printf("#<unknown %p>", (stack_head->item->content.ptr)); |
printf("#<unknown %p>", (stack_head->item->content.ptr)); |
412 |
nl(); |
nl(); |
413 |
} |
} |
414 |
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|
415 |
/* Prints the stack. */ |
/* Prints the stack. */ |
416 |
extern void printstack(environment *env) |
extern void printstack(environment *env) |
417 |
{ |
{ |
427 |
{ |
{ |
428 |
stackitem *temp= env->head; |
stackitem *temp= env->head; |
429 |
|
|
430 |
if((env->head)==NULL) { |
if(env->head==NULL || env->head->next==NULL) { |
|
printerr("Too Few Arguments"); |
|
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env->err=1; |
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return; |
|
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} |
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|
|
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if(env->head->next==NULL) { |
|
431 |
printerr("Too Few Arguments"); |
printerr("Too Few Arguments"); |
432 |
env->err=1; |
env->err=1; |
433 |
return; |
return; |
438 |
env->head->next= temp; |
env->head->next= temp; |
439 |
} |
} |
440 |
|
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stackitem* copy(stackitem* in_item) |
|
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{ |
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stackitem *out_item= malloc(sizeof(stackitem)); |
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memcpy(out_item, in_item, sizeof(stackitem)); |
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out_item->next= NULL; |
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return out_item; |
|
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} |
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|
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|
441 |
/* Recall a value from a symbol, if bound */ |
/* Recall a value from a symbol, if bound */ |
442 |
extern void rcl(environment *env) |
extern void rcl(environment *env) |
443 |
{ |
{ |
466 |
push_val(&(env->head), val); /* Return its bound value */ |
push_val(&(env->head), val); /* Return its bound value */ |
467 |
} |
} |
468 |
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|
469 |
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void stack_read(environment*, char*); |
470 |
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|
471 |
/* If the top element is a symbol, determine if it's bound to a |
/* If the top element is a symbol, determine if it's bound to a |
472 |
function value, and if it is, toss the symbol and execute the |
function value, and if it is, toss the symbol and execute the |
473 |
function. */ |
function. */ |
474 |
extern void eval(environment *env) |
extern void eval(environment *env) |
475 |
{ |
{ |
476 |
funcp in_func; |
funcp in_func; |
477 |
|
value* temp_val; |
478 |
|
stackitem* iterator; |
479 |
|
char* temp_string; |
480 |
|
|
481 |
if(env->head==NULL) { |
if(env->head==NULL) { |
482 |
printerr("Too Few Arguments"); |
printerr("Too Few Arguments"); |
483 |
env->err=1; |
env->err=1; |
484 |
return; |
return; |
485 |
} |
} |
486 |
|
|
487 |
/* if it's a symbol */ |
switch(env->head->item->type) { |
488 |
if(env->head->item->type==symb) { |
/* if it's a symbol */ |
489 |
|
case symb: |
490 |
rcl(env); /* get its contents */ |
rcl(env); /* get its contents */ |
491 |
if(env->err) return; |
if(env->err) return; |
492 |
if(env->head->item->type!=symb){ /* don't recurse symbols */ |
if(env->head->item->type!=symb){ /* don't recurse symbols */ |
493 |
eval(env); /* evaluate the value */ |
eval(env); /* evaluate the value */ |
494 |
return; |
return; |
495 |
} |
} |
496 |
} |
break; |
497 |
|
|
498 |
/* If it's a lone function value, run it */ |
/* If it's a lone function value, run it */ |
499 |
if(env->head->item->type==func) { |
case func: |
500 |
in_func= (funcp)(env->head->item->content.ptr); |
in_func= (funcp)(env->head->item->content.ptr); |
501 |
toss(env); |
toss(env); |
502 |
if(env->err) return; |
if(env->err) return; |
503 |
(*in_func)(env); |
(*in_func)(env); |
504 |
|
break; |
505 |
|
|
506 |
|
/* If it's a list */ |
507 |
|
case list: |
508 |
|
temp_val= env->head->item; |
509 |
|
env->head->item->refcount++; |
510 |
|
toss(env); |
511 |
|
if(env->err) return; |
512 |
|
iterator= (stackitem*)temp_val->content.ptr; |
513 |
|
while(iterator!=NULL && iterator->item!=NULL) { |
514 |
|
push_val(&(env->head), iterator->item); |
515 |
|
if(env->head->item->type==symb |
516 |
|
&& strcmp(";", ((symbol*)(env->head->item->content.ptr))->id)==0) { |
517 |
|
toss(env); |
518 |
|
if(env->err) return; |
519 |
|
eval(env); |
520 |
|
if(env->err) return; |
521 |
|
} |
522 |
|
iterator= iterator->next; |
523 |
|
} |
524 |
|
free_val(temp_val); |
525 |
|
break; |
526 |
|
|
527 |
|
/* If it's a string */ |
528 |
|
case string: |
529 |
|
temp_val= env->head->item; |
530 |
|
env->head->item->refcount++; |
531 |
|
toss(env); |
532 |
|
if(env->err) return; |
533 |
|
temp_string= malloc(strlen((char*)temp_val->content.ptr)+5); |
534 |
|
strcpy(temp_string, "[ "); |
535 |
|
strcat(temp_string, (char*)temp_val->content.ptr); |
536 |
|
strcat(temp_string, " ]"); |
537 |
|
stack_read(env, temp_string); |
538 |
|
eval(env); |
539 |
|
if(env->err) return; |
540 |
|
free_val(temp_val); |
541 |
|
free(temp_string); |
542 |
|
break; |
543 |
|
|
544 |
|
case integer: |
545 |
|
break; |
546 |
|
} |
547 |
|
} |
548 |
|
|
549 |
|
/* Reverse (flip) a list */ |
550 |
|
extern void rev(environment *env){ |
551 |
|
stackitem *old_head, *new_head, *item; |
552 |
|
|
553 |
|
if((env->head)==NULL) { |
554 |
|
printerr("Too Few Arguments"); |
555 |
|
env->err=1; |
556 |
|
return; |
557 |
|
} |
558 |
|
|
559 |
|
if(env->head->item->type!=list) { |
560 |
|
printerr("Bad Argument Type"); |
561 |
|
env->err=2; |
562 |
|
return; |
563 |
|
} |
564 |
|
|
565 |
|
old_head=(stackitem *)(env->head->item->content.ptr); |
566 |
|
new_head=NULL; |
567 |
|
while(old_head != NULL){ |
568 |
|
item=old_head; |
569 |
|
old_head=old_head->next; |
570 |
|
item->next=new_head; |
571 |
|
new_head=item; |
572 |
} |
} |
573 |
|
env->head->item->content.ptr=new_head; |
574 |
} |
} |
575 |
|
|
576 |
/* Make a list. */ |
/* Make a list. */ |
613 |
temp->item= pack; |
temp->item= pack; |
614 |
|
|
615 |
push(&(env->head), temp); |
push(&(env->head), temp); |
616 |
|
rev(env); |
617 |
} |
} |
618 |
|
|
619 |
/* Parse input. */ |
/* Parse input. */ |
623 |
int itemp; |
int itemp; |
624 |
size_t inlength= strlen(in_line)+1; |
size_t inlength= strlen(in_line)+1; |
625 |
int convert= 0; |
int convert= 0; |
|
static int non_eval_flag= 0; |
|
626 |
|
|
627 |
temp= malloc(inlength); |
temp= malloc(inlength); |
628 |
rest= malloc(inlength); |
rest= malloc(inlength); |
629 |
|
|
630 |
do { |
do { |
631 |
|
/* If comment */ |
632 |
|
if((convert= sscanf(in_line, "#%[^\n\r]", rest))) { |
633 |
|
free(temp); free(rest); |
634 |
|
return; |
635 |
|
} |
636 |
|
|
637 |
/* If string */ |
/* If string */ |
638 |
if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest))) { |
if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest))) { |
639 |
push_cstring(&(env->head), temp); |
push_cstring(&(env->head), temp); |
658 |
/* If single char */ |
/* If single char */ |
659 |
if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest))) { |
if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest))) { |
660 |
if(*temp==';') { |
if(*temp==';') { |
661 |
if(!non_eval_flag) { |
if(!env->non_eval_flag) { |
662 |
eval(env); /* Evaluate top element */ |
eval(env); /* Evaluate top element */ |
663 |
break; |
break; |
664 |
} |
} |
670 |
if(*temp==']') { |
if(*temp==']') { |
671 |
push_sym(env, "["); |
push_sym(env, "["); |
672 |
pack(env); |
pack(env); |
673 |
if(non_eval_flag!=0) |
if(env->non_eval_flag) |
674 |
non_eval_flag--; |
env->non_eval_flag--; |
675 |
break; |
break; |
676 |
} |
} |
677 |
|
|
678 |
if(*temp=='[') { |
if(*temp=='[') { |
679 |
push_sym(env, "["); |
push_sym(env, "["); |
680 |
non_eval_flag++; |
env->non_eval_flag++; |
681 |
break; |
break; |
682 |
} |
} |
683 |
} |
} |
712 |
return; |
return; |
713 |
} |
} |
714 |
|
|
715 |
|
rev(env); |
716 |
|
|
717 |
|
if(env->err) |
718 |
|
return; |
719 |
|
|
720 |
/* The first list element is the new stack head */ |
/* The first list element is the new stack head */ |
721 |
new_head= temp= env->head->item->content.ptr; |
new_head= temp= env->head->item->content.ptr; |
722 |
|
|
899 |
} |
} |
900 |
printf("okidok\n "); |
printf("okidok\n "); |
901 |
} |
} |
902 |
|
quit(&myenv); |
903 |
|
return EXIT_FAILURE; |
904 |
|
} |
905 |
|
|
906 |
exit(EXIT_SUCCESS); |
/* + */ |
907 |
|
extern void sx_2b(environment *env) { |
908 |
|
int a, b; |
909 |
|
size_t len; |
910 |
|
char* new_string; |
911 |
|
value *a_val, *b_val; |
912 |
|
|
913 |
|
if((env->head)==NULL || env->head->next==NULL) { |
914 |
|
printerr("Too Few Arguments"); |
915 |
|
env->err=1; |
916 |
|
return; |
917 |
|
} |
918 |
|
|
919 |
|
if(env->head->item->type==string |
920 |
|
&& env->head->next->item->type==string) { |
921 |
|
a_val= env->head->item; |
922 |
|
b_val= env->head->next->item; |
923 |
|
a_val->refcount++; |
924 |
|
b_val->refcount++; |
925 |
|
toss(env); if(env->err) return; |
926 |
|
toss(env); if(env->err) return; |
927 |
|
len= strlen(a_val->content.ptr)+strlen(b_val->content.ptr)+1; |
928 |
|
new_string= malloc(len); |
929 |
|
strcpy(new_string, b_val->content.ptr); |
930 |
|
strcat(new_string, a_val->content.ptr); |
931 |
|
free_val(a_val); free_val(b_val); |
932 |
|
push_cstring(&(env->head), new_string); |
933 |
|
free(new_string); |
934 |
|
return; |
935 |
|
} |
936 |
|
|
937 |
|
if(env->head->item->type!=integer |
938 |
|
|| env->head->next->item->type!=integer) { |
939 |
|
printerr("Bad Argument Type"); |
940 |
|
env->err=2; |
941 |
|
return; |
942 |
|
} |
943 |
|
a=env->head->item->content.val; |
944 |
|
toss(env); |
945 |
|
if(env->err) return; |
946 |
|
b=env->head->item->content.val; |
947 |
|
toss(env); |
948 |
|
if(env->err) return; |
949 |
|
push_int(&(env->head), a+b); |
950 |
} |
} |