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#include "json.h"
#include <assert.h>
#include <ctype.h>
#include <math.h>
#include <stdint.h>
#include <stdio.h>
#include "string.h"
typedef struct {
int value;
uintptr_t pos;
} parse_integer_result;
parse_integer_result parse_integer(Arena *a, char *src, uintptr_t pos) {
int *ints = new (a, int, 16); // TODO: reuse in parsing
int i = 0;
while (isdigit(src[pos + i])) {
int val = (src[pos + i] - '0');
ints[i] = val;
i++;
}
int result = 0;
for (int j = 0; j < i; j++) {
result += ints[j] * pow(10, (i - j - 1));
}
printf("json.parse_integer: parsed int=%d at pos=%lu\n", result, pos);
return (parse_integer_result){result, pos + i};
}
uintptr_t absorb_whitespaces(char *src, uintptr_t pos) {
int i = 0;
while (isspace(src[pos + i])) {
i++;
}
return pos + i;
}
typedef struct {
Vec *items;
uintptr_t pos;
} parse_array_result;
parse_array_result parse_array(Arena *a, char *src, uintptr_t start_pos) {
printf("json.parse_array: parsing array %s\n", src + start_pos);
assert(src[start_pos] == '[');
uintptr_t pos = start_pos + 1;
Vec *items = Vec_new(a, JSON, 0);
for (;;) {
pos = absorb_whitespaces(src, pos);
parse_integer_result result = parse_integer(a, src, pos);
assert(result.pos > pos);
items = Vec_push(a, items, &result.value);
pos = result.pos;
pos = absorb_whitespaces(src, pos);
if (src[pos] == ',') {
pos++;
} else {
break;
}
};
assert(src[pos] == ']');
return (parse_array_result){items, pos + 1};
}
typedef struct {
Str string;
uintptr_t pos;
} parse_string_result;
parse_string_result parse_string(Arena *a, char *src, uintptr_t pos) {
printf("json.parse_string: %s\n", src + pos);
assert(src[pos] == '"');
int i = 1;
while (src[pos + i] != '"' && src[pos + i - 1] != '\\') {
i++;
}
assert(src[pos + i]);
Str s = Str_copy(a, &src[pos + 1], i - 1);
return (parse_string_result){s, pos + i};
}
JSON JSON_parse(Arena *a, char *src) {
JSON json = {0};
int pos = 0;
printf("json.parse: src=%s\n", src);
if (isdigit(src[pos])) {
parse_integer_result result = parse_integer(a, src, 0);
json.integer = &result.value;
pos = result.pos;
}
if (src[pos] == '[') {
parse_array_result result = parse_array(a, src, pos);
json.array = result.items;
pos = result.pos;
}
if (src[pos] == '"') {
parse_string_result result = parse_string(a, src, pos);
json.string = &result.string;
pos = result.pos;
}
return json;
}
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