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add subexpression parser
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@dragoncoder047
dragoncoder047 authored Mar 21, 2024
1 parent c7bf6e1 commit d6ce108
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Showing 6 changed files with 131 additions and 61 deletions.
122 changes: 96 additions & 26 deletions pickle.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -172,69 +172,78 @@ static void bufcat(char** b, const char* c, int n) {
asprintf(b, "%s%.*s", *b ? *b : "", n, c);
free(ob);
}
static char revparen(char p) {
const char* a = "([{}])";
const char* b = ")]}{[(";
return b[strchr(a, p) - a];
}


static object* do_parse(pvm* vm, pstate* s, bool* error, char* special) {
static object* do_parse(pvm* vm, pstate* s, object** errors, char* special) {
char c = look;
char* b = NULL;
char* b2 = NULL;
object* result = nil;
if (isalpha(c)) {
DBG("symbol");
size_t p = pos;
while (!eofp && test(isalpha)) next;
bufcat(&b, at(p), pos - p);
result = vm->sym(b);
}
else if (isdigit(c)) {
DBG("number");
double d; int64_t n;
int num;
int ok = sscanf(here, "%lg%n", &d, &num);
if (ok == 2) result = vm->number(d);
if (ok) result = vm->number(d);
else {
ok = sscanf(here, "%" SCNi64 "%n", &n, &num);
if (ok == 2) result = vm->integer(n);
else {
*error = true;
result = vm->string("scanf error");
}
if (ok) result = vm->integer(n);
else vm->push(vm->string("scanf error"), *errors);
}
if (ok == 2) advance num;
DBG("ok = %i", ok);
if (ok) advance num;
}
else if (isspace(c) && c != '\n') {
DBG("small space");
result = vm->sym("SPACE");
while (test(isspace) && c != '\n') next;
}
else if (c == '#') {
// get comment or 1-character # operator
next;
if (look != '#') {
DBG("hash");
// it's a # operator
result = vm->sym("#");
} else {
next;
if (look != '#') {
DBG("line comment");
// it's a line comment
do bufadd(&b, look), next; while (look != '\n');
result = vm->string(b);
} else {
DBG("block comment");
// it's a block comment
bufcat(&b2, "###", 3);
next;
while (look == '#') bufadd(&b2, '#'), next;
do bufadd(&b, look), next; while (!eofp && !chomp(b2));
if (eofp) {
*error = true;
result = vm->string("error: unterminated block comment");
vm->push(vm->string("unterminated block comment"), *errors);
goto done;
}
result = vm->string(b);
}
}
}
else if (c == '"' || c == '\'') {
DBG("quote string");
char start = c;
next;
while (look != start && !eofp && look != '\n') {
// TODO: paren stack for nested interpolations (like PEP 701)
char ch = look;
if (ch == '\\') {
next;
Expand All @@ -244,12 +253,12 @@ static object* do_parse(pvm* vm, pstate* s, bool* error, char* special) {
next;
}
if (look != start) {
*error = true;
result = vm->string("error: unclosed string");
vm->push(vm->string("unclosed string"), *errors);
}
else result = vm->string(b);
}
else if (c == '\n') {
DBG("block string");
getindent:
// parser block
next; // eat newline
Expand All @@ -258,19 +267,25 @@ static object* do_parse(pvm* vm, pstate* s, bool* error, char* special) {
next;
}
if (look == '\n') {
// Blank line
free(b2);
b2 = NULL;
goto getindent;
}
if (!b2 || !strlen(b2)) {
// no indent
result = vm->sym("NEWLINE");
goto done;
}
// validate indent
for (char* c = b2; *c; c++) {
if (*c != *b2) {
*error = true;
result = vm->string("error: mix of spaces and tabs indenting block");
vm->push(vm->string("mix of spaces and tabs indenting block"), *errors);
goto done;
}
}
for (;;) {
// TODO: stop chomping with parens
// get one line
do bufadd(&b, look), next; while (!eofp && look != '\n');
bufadd(&b, '\n');
Expand All @@ -288,8 +303,7 @@ static object* do_parse(pvm* vm, pstate* s, bool* error, char* special) {
}
// not a blank line
if (has_indent) {
result = vm->string("error: unindent does not match previous indent");
*error = true;
vm->push(vm->string("unindent does not match previous indent"), *errors);
goto done;
}
// completely unindented
Expand All @@ -298,17 +312,74 @@ static object* do_parse(pvm* vm, pstate* s, bool* error, char* special) {
}
result = vm->string(b);
}
else if (c == '{') {
DBG("curly string");
object* stack = vm->cons(vm->integer((int64_t)c), nil);
next;
while (!eofp) {
char ch = look;
next;
// Check for open parens
if (strchr("([{", ch)) {
vm->push(vm->integer((int64_t)ch), stack);
}
// Check for close parens
if (strchr("}])", ch)) {
char got_opener = revparen(ch);
object* top = vm->pop(stack);
if (!top) {
vm->push(vm->string("internal parser error (curlystack empty)"), *errors);
} else {
char expected_opener = (char)vm->intof(top);
if (got_opener != expected_opener) {
vm->push(vm->string("mismatched paren"), *errors);
}
}
if (!stack) break;
}
bufadd(&b, ch);
}
if (eofp) {
vm->push(vm->string("unclosed curly string"), *errors);
}
else result = vm->string(b);
}
else if (c == '(' || c == '[') {
DBG("subexpression");
// Subexpressions and lists are treated the same right now.
// TODO: fix this
object** tail = &result;
next;
char close = revparen(c);
do {
object* item = do_parse(vm, s, errors, special);
if (*special) {
if (*special == close) goto closed;
vm->push(vm->string("mismatched paren"), *errors);
}
*tail = vm->cons(item, nil);
tail = &cdr(*tail);
} while (!eofp);
vm->push(vm->string("unclosed subexpression"), *errors);
closed:
*special = 0;
}
else if (strchr("(){}[]", c)) {
DBG("other special");
next;
*special = c;
}
else if (ispunct(c)) {
DBG("punctuation symbol");
// must test for other punctuation last to allow other special cases to take precedence
next;
bufadd(&b, c);
result = vm->sym(b);
}
else {
*error = true;
result = vm->string("unknown parser error");
DBG("other crap");
next;
vm->push(vm->string("unexpected crap"), *errors);
}
done:
free(b);
Expand All @@ -322,20 +393,19 @@ object* parse(pvm* vm, object* cookie, object* inst_type) {
DBG("parsing");
object* string = vm->pop();
if (string->type != &string_type) {
vm->push_data(vm->string("error: non string to parse()"));
vm->push_data(vm->cons(vm->string("non string to parse()"), nil));
return vm->sym("error");
}
const char* str = vm->stringof(string);
pstate s = { .data = str, .i = 0, .len = strlen(str) };
bool error = false;
char special = 0;
object* result = do_parse(vm, &s, &error, &special);
object* errors = nil;
object* result = do_parse(vm, &s, &errors, &special);
if (special) {
result = vm->string("unknown syntax error");
error = true;
vm->push(vm->string("unknown syntax error"), errors);
}
vm->push_data(result);
return error ? vm->sym("error") : nil;
vm->push_data(errors ? errors : result);
return errors ? vm->sym("error") : nil;
}

static object* get_best_match(pvm* vm, object* ast, object** env) {
Expand Down
2 changes: 1 addition & 1 deletion pickle_test.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,7 @@ int main() {
vm.push_data(vm.integer(42));
vm.push_data(st);
vm.push_data(vm.integer(42));
vm.push_data(vm.string("(+ 1 2) ## #### block comment '\n\n ###### \n\n\n foo"));
vm.push_data(vm.string("[(+ 1 2)\n## #### block comment '\n\n ###### \n\n\n foo]"));
printf("\nqueue with data: ");
vm.dump(vm.queue);
putchar('\n');
Expand Down
6 changes: 3 additions & 3 deletions test/out32.txt
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6 changes: 3 additions & 3 deletions test/out64.txt
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28 changes: 14 additions & 14 deletions test/valgrind32.txt
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28 changes: 14 additions & 14 deletions test/valgrind64.txt
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