Cell*
cell_add_str(Cell *p, const char *src) {
int len;
if (NULL == p) return NULL;
len = strlen(src)+1;
if ((len + p->length) > p->allocsize) {
if (NULL == cell_realloc(p, len + p->length))
return NULL;
}
strncpy(&p->data[p->length], src, len);
p->length = p->length + len-1;
return p;
}
Cell*
cell_add_char(Cell *p, const char src) {
int len;
if (NULL == p) return NULL;
len = 2;
if ((len + p->length) > p->allocsize) {
if (NULL == cell_realloc(p, len + p->length))
return NULL;
}
p->data[p->length] = src;
p->data[p->length+1] = 0;
p->length = p->length + len-1;
return p;
}
ReaderState* read_char(char c, ReaderState* rs) {
Cell* cell = rs->cell;
Cell* new_cell;
if (!cell) {
// make a root
cell = alloc_nil();
cell->next = alloc_nil();
*rs->stack = cell;
}
if (rs->state == PST_ATOM) {
if (c==' ' || c==13 || c==10) {
// skip whitespace
} else if (c==';') {
// comment
rs->state = PST_COMMENT;
} else if (c>='0' && c<='9') {
rs->state = PST_NUM;
rs->valuestate = VST_DEFAULT;
new_cell = alloc_int(0);
new_cell->value = c-'0';
cell->addr = new_cell;
} else if (c=='(') {
// start list
new_cell = alloc_nil();
cell->addr = new_cell;
*rs->stack = cell;
cell = new_cell;
rs->stack++;
rs->level++;
rs->state = PST_ATOM;
} else if (c==')') {
// end of list
cell = reader_end_list(cell, rs);
} else if (c=='[') {
// bytes (hex notation)
rs->state = PST_BYTES;
rs->sym_len = 0;
new_cell = alloc_bytes();
cell->addr = new_cell;
} else if (c=='"') {
// string
rs->state = PST_STR;
rs->sym_len = 0;
new_cell = alloc_string();
cell->addr = new_cell;
} else {
// symbol
rs->state = PST_SYM;
rs->sym_len = 1;
new_cell = alloc_sym(0);
new_cell->addr = cell_malloc(SYM_INIT_BUFFER_SIZE);
memset(new_cell->addr, 0, SYM_INIT_BUFFER_SIZE);
((char*)new_cell->addr)[0] = c;
new_cell->size = SYM_INIT_BUFFER_SIZE; // buffer space
cell->addr = new_cell;
}
} else if (rs->state == PST_COMMENT) {
//printf("c[%c]\n",c);
if (c=='\n' || c=='0') {
rs->state = PST_ATOM;
}
} else if (rs->state == PST_NUM || rs->state == PST_NUM_NEG) {
if (c>='0' && c<='9' || ((rs->valuestate == VST_HEX && c>='a' && c<='f'))) {
// build number
Cell* vcell = (Cell*)cell->addr;
int mul = 10;
if (rs->valuestate == VST_HEX) mul = 16;
int d = 0;
if (c>='a') {
d = 10+(c-'a');
} else {
d = c-'0';
}
if (rs->state == PST_NUM_NEG) {
vcell->value = vcell->value*mul - d;
} else {
vcell->value = vcell->value*mul + d;
}
} else if (c==' ' || c==13 || c==10) {
cell = reader_next_list_cell(cell, rs);
} else if (c==')') {
cell = reader_end_list(cell, rs);
} else if (c=='x') {
rs->valuestate = VST_HEX;
} else {
rs->state = PST_ERR_UNEXP_JUNK_IN_NUMBER;
}
} else if (rs->state == PST_SYM || rs->state == PST_STR) {
int append = 0;
if (rs->state == PST_STR) {
if (c=='"') {
// string is over
Cell* vcell = (Cell*)cell->addr;
vcell->size = (rs->sym_len);
cell = reader_next_list_cell(cell, rs);
} else {
append = 1;
}
}
else {
if (c==')') {
cell = reader_end_list(cell, rs);
} else if (c==' ' || c==13 || c==10) {
cell = reader_next_list_cell(cell, rs);
} else if (rs->state == PST_SYM && (c>='0' && c<='9')) {
Cell* vcell = (Cell*)cell->addr;
// detect negative number
if (((char*)vcell->addr)[0] == '-') {
// we're actually not a symbol, correct the cell.
rs->state = PST_NUM_NEG;
vcell->tag = TAG_INT;
vcell->value = -(c-'0');
}
} else {
append = 1;
}
}
if (append) {
// build symbol/string
Cell* vcell = (Cell*)cell->addr;
int idx = rs->sym_len;
rs->sym_len++;
if (rs->sym_len>=vcell->size-1) {
// grow buffer
vcell->addr = cell_realloc(vcell->addr, vcell->size, 2*vcell->size);
memset(vcell->addr+vcell->size, 0, vcell->size);
vcell->size = 2*vcell->size;
}
((char*)vcell->addr)[idx] = c;
}
} else if (rs->state == PST_BYTES) {
if (c==']') {
Cell* vcell = (Cell*)cell->addr;
vcell->size = (rs->sym_len)/2;
cell = reader_next_list_cell(cell, rs);
} else if ((c>='0' && c<='9') || (c>='a' && c<='f') || (c>='A' && c<='F')) {
int n = c;
if (n>='a') n-=('a'-'9'-1); // hex 'a' to 10 offset
if (n>='A') n-=('A'-'9'-1); // hex 'a' to 10 offset
n-='0'; // char to value
Cell* vcell = (Cell*)cell->addr;
int idx = rs->sym_len;
rs->sym_len++;
if (rs->sym_len>=(vcell->size/2)-1) {
// grow buffer
vcell->addr = cell_realloc(vcell->addr, vcell->size, 2*vcell->size); // TODO: check the math
memset(vcell->addr+vcell->size, 0, vcell->size);
vcell->size = 2*vcell->size;
}
if (idx%2==0) { // even digit
((byte*)vcell->addr)[idx/2] = n<<4; // high nybble
} else { // odd digit
((byte*)vcell->addr)[idx/2] |= n;
}
} else if (c==' ' || c==13 || c==10) {
// skip
} else {
rs->state = PST_ERR_UNEXP_JUNK_IN_BYTES;
}
}
rs->cell = cell;
return rs;
}
