refactor json

Makefile

@@ -11,6 +11,8 @@ obj_dir = $(build_dir)/obj
 
 sources = \
 	src/main.c \
+	src/json_parse.c \
+	src/json_value.c \
 	src/collections.c
 
 target=$(build_dir)/jq

data.json

@@ -1,4 +1,5 @@
 {
-    "foo": "bar"
+    "baz": false,
+    "foo": [123, "bar"]
 }
 

src/collections.c

@@ -6,6 +6,13 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define MIN(A, B) ((A) <= (B) ? (A) : (B))
+
+#define MAX(A, B) ((A) >= (B) ? (A) : (B))
+
+#define ALIGN(VAL, ALIGN)                                                      \
+    ((VAL) % (ALIGN) != 0 ? (VAL) + ((ALIGN) - (VAL) % (ALIGN)) : (VAL))
+
 void *array_push(void **data,
     size_t *capacity,
     size_t *count,
@@ -51,6 +58,90 @@ void *array_insert_at(void **data,
     return src_ptr;
 }
 
+void smallarray_construct(struct smallarray *a)
+{
+    *a = (struct smallarray) { 0 };
+}
+
+void smallarray_destroy(struct smallarray *a)
+{
+    if ((a->smalldata[0] & 1) == 0 && a->data) {
+        free(a->data);
+    }
+}
+
+static bool sa_is_big(struct smallarray const *a)
+{
+    return a->data && (a->smalldata[0] & 1) == 0;
+}
+
+static void sa_push_big(struct smallarray *a, void *value)
+{
+    size_t capacity = 8;
+    void **ptr = malloc(capacity * sizeof(void *));
+    size_t count = 0;
+
+    for (size_t i = 0; i < 3; ++i) {
+        if ((a->smalldata[i] & 1) == 0)
+            break;
+        ptr[i] = (void *)(a->smalldata[i] & ~1ull);
+        count += 1;
+    }
+
+    a->capacity = capacity;
+    a->data = ptr;
+    a->count = count;
+    array_push(
+        (void **)&a->data, &a->capacity, &a->count, &value, sizeof(void *));
+}
+
+static void sa_push_small(struct smallarray *a, void *value)
+{
+    for (size_t i = 0; i < 3; ++i) {
+        if (a->smalldata[i] & 1)
+            continue;
+        a->smalldata[i] = (size_t)value | 1;
+        return;
+    }
+}
+
+void smallarray_push(struct smallarray *a, void *value)
+{
+    assert((size_t)value % 2 == 0 && "pointer must be 2 bytes aligned");
+
+    if (sa_is_big(a)) {
+        sa_push_big(a, value);
+    } else {
+        sa_push_small(a, value);
+    }
+}
+
+size_t smallarray_count(struct smallarray const *a)
+{
+    if (sa_is_big(a)) {
+        return a->count;
+    } else {
+        size_t count = 0;
+        for (size_t i = 0; i < 3; ++i) {
+            if ((a->smalldata[i] & 1) == 0)
+                break;
+            count += 1;
+        }
+        return count;
+    }
+}
+
+void *smallarray_get(struct smallarray *a, size_t idx)
+{
+    if (sa_is_big(a)) {
+        return a->data[idx];
+    } else {
+        if (idx >= 3 || (a->smalldata[idx] & 1) == 0)
+            return NULL;
+        return (void *)(a->smalldata[idx] & ~1ull);
+    }
+}
+
 static uint64_t hash_key(char const *data)
 {
     // djb2
@@ -65,6 +156,20 @@ static uint64_t hash_key(char const *data)
     return hash;
 }
 
+static uint64_t hash_key_sized(char const *data, size_t size)
+{
+    // djb2
+
+    uint64_t hash = 5381;
+    unsigned char c;
+
+    while (size-- > 0 && (c = (unsigned char)*data++)) {
+        hash = ((hash << 5) + hash) + c; // hash * 33 + c
+    }
+
+    return hash;
+}
+
 void hashmap_construct(struct hashmap *t)
 {
     *t = (struct hashmap) { NULL, 0, 0 };
@@ -79,16 +184,16 @@ void hashmap_destroy(struct hashmap *t)
 
 static struct hash_entry *find_entry(struct hashmap *m, uint64_t hash)
 {
-    for (size_t b_idx = 0; b_idx < m->buckets_count; ++b_idx) {
-        struct hash_bucket *bucket = &m->buckets[b_idx];
-        if (hash < bucket->first_hash || hash > bucket->last_hash) {
+    for (size_t i = 0; i < m->buckets_count; ++i) {
+        struct hash_bucket *bucket = &m->buckets[i];
+        if (hash < bucket->first_hash)
+            break;
+        if (hash > bucket->last_hash)
             continue;
-        }
-        for (size_t e_idx = 0; e_idx < bucket->count; ++e_idx) {
-            struct hash_entry *entry = &bucket->entries[e_idx];
-            if (entry->hash == hash) {
+        for (size_t j = 0; j < bucket->count; ++j) {
+            struct hash_entry *entry = &bucket->entries[j];
+            if (entry->hash == hash)
                 return entry;
-            }
         }
     }
     return NULL;
@@ -111,9 +216,6 @@ static struct hash_bucket *insert_bucket_at(struct hashmap *m, size_t idx)
         sizeof(struct hash_bucket));
 }
 
-#define MIN(A, B) ((A) <= (B) ? (A) : (B))
-#define MAX(A, B) ((A) >= (B) ? (A) : (B))
-
 static struct hash_entry *add_entry_to_bucket(
     struct hash_bucket *b, uint64_t hash)
 {
@@ -154,10 +256,8 @@ static struct hash_entry *make_entry(struct hashmap *m, uint64_t hash)
     assert(false);
 }
 
-void hashmap_set(struct hashmap *m, char const *key, void *value)
+static void hashmap_set_internal(struct hashmap *m, uint64_t hash, void *value)
 {
-    uint64_t hash = hash_key(key);
-
     if (m->buckets_count == 0) {
         struct hash_bucket *bucket = insert_bucket_at(m, 0);
         bucket->entries[0] = (struct hash_entry) { hash, value };
@@ -176,15 +276,77 @@ void hashmap_set(struct hashmap *m, char const *key, void *value)
     return;
 }
 
+void hashmap_set(struct hashmap *m, char const *key, void *value)
+{
+    uint64_t hash = hash_key(key);
+    hashmap_set_internal(m, hash, value);
+}
+
+void hashmap_set_sized(
+    struct hashmap *m, char const *key, size_t key_size, void *value)
+{
+    uint64_t hash = hash_key_sized(key, key_size);
+    hashmap_set_internal(m, hash, value);
+}
+
 bool hashmap_has(struct hashmap *m, char const *key)
 {
     uint64_t hash = hash_key(key);
     return find_entry(m, hash) != NULL;
 }
 
-void *hashmap_get(struct hashmap *m, char const *key)
+static void *hashmap_get_internal(struct hashmap *m, uint64_t hash)
 {
-    uint64_t hash = hash_key(key);
     struct hash_entry *entry = find_entry(m, hash);
     return entry ? entry->value : NULL;
 }
+void *hashmap_get(struct hashmap *m, char const *key)
+{
+    uint64_t hash = hash_key(key);
+    return hashmap_get_internal(m, hash);
+}
+void *hashmap_get_sized(struct hashmap *m, char const *key, size_t key_size)
+{
+    uint64_t hash = hash_key_sized(key, key_size);
+    return hashmap_get_internal(m, hash);
+}
+
+struct blockalloc_block {
+    unsigned char *data;
+    size_t size;
+};
+
+void blockalloc_construct(struct blockalloc *a)
+{
+    *a = (struct blockalloc) { NULL, 0, 0, 0 };
+}
+
+void blockalloc_destroy(struct blockalloc *a)
+{
+    if (a->blocks)
+        free(a->blocks);
+}
+
+void *blockalloc_alloc(struct blockalloc *a, size_t size, size_t align)
+{
+    size_t p = ALIGN(a->p, align);
+    if (!a->blocks || p + size > a->blocks[a->count - 1].size) {
+        size_t block_size = MAX(blockalloc_default_block, size);
+
+        struct blockalloc_block block = {
+            .data = malloc(block_size),
+            .size = block_size,
+        };
+
+        array_push((void **)&a->blocks,
+            &a->capacity,
+            &a->count,
+            &block,
+            sizeof(struct blockalloc_block));
+        a->p = 0;
+        p = 0;
+    }
+    void *ptr = &a->blocks[a->count - 1].data[p];
+    a->p = p + size;
+    return ptr;
+}

src/collections.h

@@ -18,6 +18,23 @@ void *array_insert_at(void **data,
     void const *elem,
     size_t elem_size);
 
+struct smallarray {
+    union {
+        size_t smalldata[3];
+        struct {
+            void **data;
+            size_t capacity;
+            size_t count;
+        };
+    };
+};
+
+void smallarray_construct(struct smallarray *a);
+void smallarray_destroy(struct smallarray *a);
+void smallarray_push(struct smallarray *a, void *value);
+size_t smallarray_count(struct smallarray const *a);
+void *smallarray_get(struct smallarray *a, size_t idx);
+
 struct hash_entry {
     uint64_t hash;
     void *value;
@@ -41,7 +58,25 @@ struct hashmap {
 void hashmap_construct(struct hashmap *m);
 void hashmap_destroy(struct hashmap *m);
 void hashmap_set(struct hashmap *m, char const *key, void *value);
+void hashmap_set_sized(
+    struct hashmap *m, char const *key, size_t key_size, void *value);
 bool hashmap_has(struct hashmap *m, char const *key);
 void *hashmap_get(struct hashmap *m, char const *key);
+void *hashmap_get_sized(struct hashmap *m, char const *key, size_t key_size);
+
+#define blockalloc_default_block 4096
+
+struct blockalloc_block;
+
+struct blockalloc {
+    struct blockalloc_block *blocks;
+    size_t capacity;
+    size_t count;
+    size_t p;
+};
+
+void blockalloc_construct(struct blockalloc *a);
+void blockalloc_destroy(struct blockalloc *a);
+void *blockalloc_alloc(struct blockalloc *a, size_t size, size_t align);
 
 #endif

src/json.h

@@ -0,0 +1,51 @@
+#ifndef JSON_H
+#define JSON_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+enum json_type {
+    json_null = 1,
+    json_false = 2,
+    json_true = 3,
+    json_int,
+    json_float,
+    json_string,
+    json_array,
+    json_object,
+};
+
+struct json_value;
+
+struct json_value *json_new(enum json_type type);
+void json_free(struct json_value *value);
+
+bool json_is(struct json_value const *value, enum json_type type);
+
+bool json_get_bool(struct json_value const *value);
+int64_t json_get_int(struct json_value const *value);
+double json_get_float(struct json_value const *value);
+char *json_get_string(struct json_value *value);
+
+void json_set_bool(struct json_value *value, bool val);
+void json_set_int(struct json_value *value, int64_t val);
+void json_set_float(struct json_value *value, double val);
+void json_set_string(struct json_value *value, char *val);
+
+struct json_value *json_idx(struct json_value *array, size_t idx);
+void json_push(struct json_value *array, struct json_value *value);
+
+struct json_value *json_key(struct json_value *object, char const *key);
+struct json_value *json_key_sized(
+    struct json_value *object, char const *key, size_t key_size);
+void json_set(
+    struct json_value *object, char const *key, struct json_value *value);
+void json_set_sized(struct json_value *object,
+    char const *key,
+    size_t key_size,
+    struct json_value *value);
+
+struct json_value *json_parse(char const *text, size_t text_size);
+
+#endif

src/json_parse.c

@@ -0,0 +1,339 @@
+#include "collections.h"
+#include "json.h"
+#include <assert.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct loc {
+    size_t idx;
+    int line;
+    int col;
+};
+
+static void report(
+    struct loc loc, char const *message, char const *text, size_t text_len)
+{
+    fprintf(stderr, "error: %s\n", message);
+    if (!text)
+        return;
+    assert(text[loc.idx] != '\n');
+    size_t line_begin_idx = loc.idx;
+    while (line_begin_idx > 0 && text[line_begin_idx] != '\n') {
+        line_begin_idx -= 1;
+    }
+    if (text[line_begin_idx] == '\n') {
+        line_begin_idx += 1;
+    }
+    size_t line_end_idx = loc.idx + 1;
+    while (line_end_idx < text_len && text[line_end_idx] != '\n') {
+        line_end_idx += 1;
+    }
+    if (line_end_idx >= text_len || text[line_end_idx] == '\n') {
+        line_end_idx -= 1;
+    }
+    int linenr_width = snprintf(NULL, 0, "%d", loc.line);
+    static char const *spaces = "                        ";
+    printf("%.*s|\n"
+           "%d|%.*s\n"
+           "%.*s|%.*s^\n"
+           "%.*s|\n",
+        linenr_width,
+        spaces,
+        loc.line,
+        (int)(line_end_idx - line_begin_idx + 1),
+        &text[line_begin_idx],
+        linenr_width,
+        spaces,
+        loc.col - 1,
+        spaces,
+        linenr_width,
+        spaces);
+}
+
+enum tokty {
+    tt_eof,
+    tt_null = json_null,
+    tt_false = json_false,
+    tt_true = json_true,
+    tt_string,
+    tt_float,
+    tt_int = '0',
+    tt_comma = ',',
+    tt_colon = ':',
+    tt_lbracket = '[',
+    tt_rbracket = ']',
+    tt_lbrace = '{',
+    tt_rbrace = '}',
+};
+
+struct tok {
+    enum tokty ty;
+    char const *ptr;
+    size_t len;
+    struct loc loc;
+};
+
+struct tokenizer {
+    char const *text;
+    size_t len;
+    size_t idx;
+    int line;
+    int col;
+    bool failed;
+};
+
+static void t_step(struct tokenizer *t)
+{
+    if (t->idx >= t->len)
+        return;
+    if (t->text[t->idx] == '\n') {
+        t->line += 1;
+        t->col = 1;
+    } else {
+        t->col += 1;
+    }
+    t->idx += 1;
+}
+
+static struct tok t_tok(struct tokenizer *t, enum tokty ty, struct loc loc)
+{
+    return (struct tok) { ty, &t->text[loc.idx], t->idx - loc.idx, loc };
+}
+
+static struct tok tokenizer_next(struct tokenizer *t);
+
+static struct tok t_make_ident_tok(
+    struct tokenizer *t, struct loc loc, size_t *i)
+{
+    char const *kws[] = { "null", "false", "true" };
+    enum tokty tys[] = { tt_null, tt_false, tt_true };
+    for (size_t kw_i = 0; kw_i < sizeof(kws) / sizeof(kws[0]); ++kw_i) {
+        if (strncmp(kws[kw_i], &t->text[loc.idx], *i - loc.idx)) {
+            return t_tok(t, tys[kw_i], loc);
+        }
+    }
+    report(loc, "invalid identifier", t->text, t->len);
+    t->failed = true;
+    return tokenizer_next(t);
+}
+
+static struct tok t_make_number_tok(
+    struct tokenizer *t, struct loc loc, size_t *i)
+{
+    while (*i < t->len && t->text[*i] >= '0' && t->text[*i] <= '9') {
+        t_step(t);
+    }
+    enum tokty ty = tt_int;
+    if (*i < t->len && t->text[*i] == '.') {
+        ty = tt_float;
+        t_step(t);
+        while (*i < t->len && t->text[*i] >= '0' && t->text[*i] <= '9') {
+            t_step(t);
+        }
+    }
+    return t_tok(t, ty, loc);
+}
+
+static struct tok t_make_string_tok(
+    struct tokenizer *t, struct loc loc, size_t *i)
+{
+    t_step(t);
+    while (*i < t->len && t->text[*i] != '\"') {
+        if (t->text[*i] == '\\') {
+            t_step(t);
+            if (*i >= t->len)
+                break;
+        }
+        t_step(t);
+    }
+    if (*i >= t->len && t->text[*i] != '\"') {
+        report(loc, "malformed string", t->text, t->len);
+        t->failed = true;
+        return tokenizer_next(t);
+    }
+    t_step(t);
+    return t_tok(t, tt_string, loc);
+}
+
+static struct tok tokenizer_next(struct tokenizer *t)
+{
+    struct loc loc = { t->idx, t->line, t->col };
+    size_t *i = &t->idx;
+    if (*i >= t->len) {
+        return t_tok(t, tt_eof, loc);
+    }
+    bool matched = false;
+    while (*i < t->len && strchr(" \t\r\n", t->text[*i]) != NULL) {
+        matched = true;
+        t_step(t);
+    }
+    if (matched) {
+        return tokenizer_next(t);
+    }
+    if (strchr(",:[]{}0", t->text[*i]) != NULL) {
+        enum tokty ty = (enum tokty)t->text[*i];
+        t_step(t);
+        return t_tok(t, ty, loc);
+    }
+    while (*i < t->len && t->text[*i] >= 'a' && t->text[*i] <= 'z') {
+        matched = true;
+        t_step(t);
+    }
+    if (matched) {
+        return t_make_ident_tok(t, loc, i);
+    }
+    if (t->text[*i] >= '1' && t->text[*i] <= '9') {
+        return t_make_number_tok(t, loc, i);
+    }
+    if (t->text[*i] == '\"') {
+        return t_make_string_tok(t, loc, i);
+    }
+    report(loc, "illegal character", t->text, t->len);
+    t->failed = true;
+    t_step(t);
+    return tokenizer_next(t);
+}
+
+struct parser {
+    struct tokenizer tokenizer;
+    struct tok tok;
+    struct blockalloc allocator;
+};
+
+static void p_step(struct parser *p)
+{
+    p->tok = tokenizer_next(&p->tokenizer);
+}
+
+static void parser_construct(
+    struct parser *p, char const *text, size_t text_len)
+{
+    *p = (struct parser) {
+        .tokenizer = (struct tokenizer) { text, text_len, 0, 1, 1, false },
+        .tok = (struct tok) { 0 },
+        .allocator = (struct blockalloc) { 0 },
+    };
+    blockalloc_construct(&p->allocator);
+    p_step(p);
+}
+
+static void p_report(struct parser *p, struct loc loc, char const *message)
+{
+    report(loc, message, p->tokenizer.text, p->tokenizer.len);
+}
+
+static struct json_value *parser_parse(struct parser *p);
+
+static struct json_value *parser_parse_array(struct parser *p, enum tokty *ty)
+{
+    p_step(p);
+    struct json_value *val = json_new(json_array);
+    bool tail = false;
+    while (*ty != tt_eof && ((!tail && *ty != ']') || (tail && *ty == ','))) {
+        if (tail)
+            p_step(p);
+        struct json_value *child = parser_parse(p);
+        if (!child)
+            goto array_leave_error_free_val;
+        json_push(val, child);
+        tail = true;
+    }
+    if (*ty == tt_eof || *ty != ']') {
+        p_report(p, p->tok.loc, "expected ']'");
+        goto array_leave_error_free_val;
+    }
+    p_step(p);
+    return val;
+array_leave_error_free_val:
+    json_free(val);
+    return NULL;
+}
+
+static struct json_value *parser_parse_object(struct parser *p, enum tokty *ty)
+{
+    p_step(p);
+    struct json_value *val = json_new(json_object);
+    bool tail = false;
+    while (*ty != tt_eof && ((!tail && *ty != '}') || (tail && *ty == ','))) {
+        if (tail)
+            p_step(p);
+        if (*ty != tt_string) {
+            p_report(p, p->tok.loc, "expected string");
+            goto object_leave_error_free_val;
+        }
+        struct tok key_tok = p->tok;
+        p_step(p);
+        if (*ty != ':') {
+            p_report(p, p->tok.loc, "expected ':'");
+            goto object_leave_error_free_val;
+        }
+        p_step(p);
+        struct json_value *child = parser_parse(p);
+        if (!child)
+            goto object_leave_error_free_val;
+        json_set_sized(val, key_tok.ptr + 1, key_tok.len - 2, child);
+        tail = true;
+    }
+    if (*ty == tt_eof || *ty != '}') {
+        p_report(p, p->tok.loc, "expected '}'");
+        goto object_leave_error_free_val;
+    }
+    p_step(p);
+    return val;
+object_leave_error_free_val:
+    json_free(val);
+    return NULL;
+}
+
+static struct json_value *parser_parse(struct parser *p)
+{
+    struct loc loc = p->tok.loc;
+    enum tokty *ty = &p->tok.ty;
+
+    if (*ty == tt_null || *ty == tt_false || *ty == tt_true) {
+        struct json_value *val = json_new((enum json_type) * ty);
+        p_step(p);
+        return val;
+    } else if (*ty == tt_int) {
+        int64_t value = strtol(p->tok.ptr, NULL, 10);
+        struct json_value *val = json_new(json_int);
+        json_set_int(val, value);
+        p_step(p);
+        return val;
+    } else if (*ty == tt_float) {
+        double value = strtod(p->tok.ptr, NULL);
+        struct json_value *val = json_new(json_float);
+        json_set_float(val, value);
+        p_step(p);
+        return val;
+    } else if (*ty == tt_string) {
+        char *value = blockalloc_alloc(&p->allocator, p->tok.len - 2 + 1, 2);
+        strncpy(value, p->tok.ptr + 1, p->tok.len - 2);
+        value[p->tok.len - 2] = '\0';
+        struct json_value *val = json_new(json_string);
+        json_set_string(val, value);
+        p_step(p);
+        return val;
+    } else if (*ty == '[') {
+        return parser_parse_array(p, ty);
+    } else if (*ty == '{') {
+        return parser_parse_object(p, ty);
+    } else {
+        p_report(p, loc, "expected expression");
+        return NULL;
+    }
+}
+
+struct json_value *json_parse(char const *text, size_t text_size)
+{
+    text_size = text_size > 0 ? text_size : strlen(text);
+
+    struct parser p;
+    parser_construct(&p, text, text_size);
+
+    return parser_parse(&p);
+}

src/json_value.c

@@ -0,0 +1,153 @@
+#include "collections.h"
+#include "json.h"
+#include <assert.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct json_value {
+    enum json_type ty;
+    union {
+        int64_t int_val;
+        double float_val;
+        char *string_val;
+        struct smallarray array_vals;
+        struct hashmap object_fields;
+    };
+};
+
+struct json_value *json_new(enum json_type ty)
+{
+    struct json_value *v = malloc(sizeof(struct json_value));
+    *v = (struct json_value) { .ty = ty };
+    switch (ty) {
+        case json_null:
+        case json_false:
+        case json_true:
+        case json_int:
+        case json_float:
+        case json_string:
+            break;
+        case json_array:
+            smallarray_construct(&v->array_vals);
+            break;
+        case json_object:
+            hashmap_construct(&v->object_fields);
+            break;
+    }
+    return v;
+}
+
+void json_free(struct json_value *v)
+{
+    switch (v->ty) {
+        case json_null:
+        case json_false:
+        case json_true:
+        case json_int:
+        case json_float:
+            break;
+        case json_string:
+            if (v->string_val)
+                free(v->string_val);
+            break;
+        case json_array:
+            smallarray_destroy(&v->array_vals);
+            break;
+        case json_object:
+            hashmap_destroy(&v->object_fields);
+            break;
+    }
+    free(v);
+}
+
+bool json_is(struct json_value const *value, enum json_type type)
+{
+    return value->ty == type;
+}
+
+bool json_get_bool(struct json_value const *value)
+{
+    assert(value->ty == json_true || value->ty == json_false);
+    return value->ty == json_true;
+}
+int64_t json_get_int(struct json_value const *value)
+{
+    assert(value->ty == json_int);
+    return value->int_val;
+}
+double json_get_float(struct json_value const *value)
+{
+    assert(value->ty == json_float);
+    return value->float_val;
+}
+char *json_get_string(struct json_value *value)
+{
+    assert(value->ty == json_string);
+    return value->string_val;
+}
+
+void json_set_bool(struct json_value *value, bool val)
+{
+    assert(value->ty == json_true || value->ty == json_false);
+    value->ty = val ? json_true : json_false;
+}
+void json_set_int(struct json_value *value, int64_t val)
+{
+    assert(value->ty == json_int);
+    value->int_val = val;
+}
+void json_set_float(struct json_value *value, double val)
+{
+    assert(value->ty == json_float);
+    value->float_val = val;
+}
+void json_set_string(struct json_value *value, char *val)
+{
+    assert(value->ty == json_string);
+    value->string_val = val;
+}
+
+struct json_value *json_idx(struct json_value *array, size_t idx)
+{
+    assert(array->ty == json_array);
+    return smallarray_get(&array->array_vals, idx);
+}
+
+void json_push(struct json_value *array, struct json_value *value)
+{
+    assert(array->ty == json_array);
+    smallarray_push(&array->array_vals, value);
+}
+
+struct json_value *json_key(struct json_value *object, char const *key)
+{
+    assert(object->ty == json_object);
+    return hashmap_get(&object->object_fields, key);
+}
+
+struct json_value *json_key_sized(
+    struct json_value *object, char const *key, size_t key_size)
+{
+    assert(object->ty == json_object);
+    return hashmap_get_sized(&object->object_fields, key, key_size);
+}
+
+void json_set(
+    struct json_value *object, char const *key, struct json_value *value)
+{
+    assert(object->ty == json_object);
+    hashmap_set(&object->object_fields, key, value);
+}
+
+void json_set_sized(struct json_value *object,
+    char const *key,
+    size_t key_size,
+    struct json_value *value)
+{
+    assert(object->ty == json_object);
+    hashmap_set_sized(&object->object_fields, key, key_size, value);
+}

src/main.c

@@ -1,4 +1,5 @@
 #include "collections.h"
+#include "json.h"
 #include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
@@ -8,197 +9,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-struct loc {
-    size_t idx;
-    int line;
-    int col;
-};
-
-void report(
-    struct loc loc, char const *message, char const *text, size_t text_len)
-{
-    fprintf(stderr, "error: %s\n", message);
-    if (!text)
-        return;
-    assert(text[loc.idx] != '\n');
-    size_t line_begin_idx = loc.idx;
-    while (line_begin_idx > 0 && text[line_begin_idx] != '\n') {
-        line_begin_idx -= 1;
-    }
-    if (text[line_begin_idx] == '\n') {
-        line_begin_idx += 1;
-    }
-    size_t line_end_idx = loc.idx + 1;
-    while (line_end_idx < text_len && text[line_end_idx] != '\n') {
-        line_end_idx += 1;
-    }
-    if (line_end_idx >= text_len || text[line_end_idx] == '\n') {
-        line_end_idx -= 1;
-    }
-    int linenr_width = snprintf(NULL, 0, "%d", loc.line);
-    static char const *spaces = "                        ";
-    printf("%.*s|\n"
-           "%d|%.*s\n"
-           "%.*s|%.*s^\n"
-           "%.*s|\n",
-        linenr_width,
-        spaces,
-        loc.line,
-        (int)(line_end_idx - line_begin_idx + 1),
-        &text[line_begin_idx],
-        linenr_width,
-        spaces,
-        loc.col - 1,
-        spaces,
-        linenr_width,
-        spaces);
-}
-
-enum tokty {
-    tt_eof,
-    tt_null,
-    tt_false,
-    tt_true,
-    tt_string,
-    tt_float,
-    tt_int = '0',
-    tt_comma = ',',
-    tt_colon = ':',
-    tt_lbracket = '[',
-    tt_rbracket = ']',
-    tt_lbrace = '{',
-    tt_rbrace = '}',
-};
-
-struct tok {
-    enum tokty ty;
-    char const *ptr;
-    size_t len;
-    struct loc loc;
-};
-
-struct tokenizer {
-    char const *text;
-    size_t len;
-    size_t idx;
-    int line;
-    int col;
-    bool failed;
-};
-
-static void t_step(struct tokenizer *t)
-{
-    if (t->idx >= t->len)
-        return;
-    if (t->text[t->idx] == '\n') {
-        t->line += 1;
-        t->col = 1;
-    } else {
-        t->col += 1;
-    }
-    t->idx += 1;
-}
-
-static struct tok t_tok(struct tokenizer *t, enum tokty ty, struct loc loc)
-{
-    return (struct tok) { ty, &t->text[loc.idx], t->idx - loc.idx, loc };
-}
-
-struct tok tokenizer_next(struct tokenizer *t)
-{
-    struct loc loc = { t->idx, t->line, t->col };
-    size_t *i = &t->idx;
-    if (*i >= t->len) {
-        return t_tok(t, tt_eof, loc);
-    }
-    bool matched = false;
-    while (*i < t->len && strchr(" \t\r\n", t->text[*i]) != NULL) {
-        matched = true;
-        *i += 1;
-    }
-    if (matched) {
-        return tokenizer_next(t);
-    }
-    if (strchr(",:[]{}0", t->text[*i]) != NULL) {
-        enum tokty ty = (enum tokty)t->text[*i];
-        *i += 1;
-        return t_tok(t, ty, loc);
-    }
-    while (*i < t->len && t->text[*i] >= 'a' && t->text[*i] <= 'z') {
-        matched = true;
-        *i += 1;
-    }
-    if (matched) {
-        char const *kws[] = { "null", "false", "true" };
-        enum tokty tys[] = { tt_null, tt_false, tt_true };
-        for (size_t kw_i = 0; kw_i < sizeof(kws) / sizeof(kws[0]); ++kw_i) {
-            if (strncmp(kws[kw_i], &t->text[loc.idx], *i - loc.idx)) {
-                return t_tok(t, tys[kw_i], loc);
-            }
-        }
-        report(loc, "invalid identifier", t->text, t->len);
-        t->failed = true;
-        return tokenizer_next(t);
-    }
-    if (t->text[*i] >= '1' && t->text[*i] <= '9') {
-        while (*i < t->len && t->text[*i] >= '0' && t->text[*i] <= '9') {
-            *i += 1;
-        }
-        enum tokty ty = tt_int;
-        if (*i < t->len && t->text[*i] == '.') {
-            ty = tt_float;
-            *i += 1;
-            while (*i < t->len && t->text[*i] >= '0' && t->text[*i] <= '9') {
-                *i += 1;
-            }
-        }
-        return t_tok(t, ty, loc);
-    }
-    if (t->text[*i] == '\"') {
-        i += 1;
-        while (*i < t->len && t->text[*i] != '\"') {
-            if (t->text[*i] != '\\') {
-                *i += 1;
-                if (*i >= t->len)
-                    break;
-            }
-            *i += 1;
-        }
-        if (*i >= t->len && t->text[*i] != '\"') {
-            report(loc, "malformed string", t->text, t->len);
-            t->failed = true;
-            return tokenizer_next(t);
-        }
-        *i += 1;
-        return t_tok(t, tt_string, loc);
-    }
-    report(loc, "illegal character", t->text, t->len);
-    t->failed = true;
-    *i += 1;
-    return tokenizer_next(t);
-}
-
-enum valty {
-    vt_null,
-    vt_number,
-    vt_string,
-    vt_array,
-    vt_object,
-};
-
-struct val {
-    enum valty ty;
-    union {
-        int64_t int_val;
-        double float_val;
-        char *string_val;
-        struct {
-            struct val *array_data;
-            size_t *array_count;
-        };
-    };
-};
-
 int main(int argc, char *argv[])
 {
     if (argc < 3) {
@@ -238,68 +48,16 @@ int main(int argc, char *argv[])
     }
     fclose(file);
 
-    struct tokenizer tokenizer = { text, file_size, 0, 1, 1, false };
-
+    struct json_value *val = json_parse(text, file_size);
     free(text);
 
-    char const *keys[] = {
-        "first",
-        "second",
-        "third",
-        "fourth",
-        "fifth",
-        "sixth",
-        "seventh",
-        "eigth",
-        "ninth",
-        "tenth",
-        "first",
-        "seventh",
-        "tenth",
-    };
-    char const *values[] = {
-        "salery",
-        "policy",
-        "strike",
-        "prophecy",
-        "break",
-        "down",
-        "think",
-        "about",
-        "honey",
-        "and",
-        "the",
-        "sweet",
-        "sounds",
-    };
+    typedef struct json_value V;
 
-    struct hashmap map;
-    hashmap_construct(&map);
+    V *a = json_key(val, "foo");
+    V *b = json_idx(a, 0);
+    V *c = json_idx(a, 1);
+    printf(".foo[0] = %ld\n", json_get_int(b));
+    printf(".foo[1] = %s\n", json_get_string(c));
 
-    for (size_t i = 0; i < sizeof(keys) / sizeof(keys[0]); ++i) {
-        hashmap_set(&map, keys[i], (void *)values[i]);
-    }
-
-    for (size_t i = 0; i < sizeof(keys) / sizeof(keys[0]); ++i) {
-        assert(hashmap_has(&map, keys[i]));
-    }
-
-    for (size_t i = 0; i < sizeof(keys) / sizeof(keys[0]); ++i) {
-        switch (i) {
-            case 0:
-                assert(hashmap_get(&map, keys[i]) == values[10]);
-                break;
-            case 6:
-                assert(hashmap_get(&map, keys[i]) == values[11]);
-                break;
-            case 9:
-                assert(hashmap_get(&map, keys[i]) == values[12]);
-                break;
-            default:
-                assert(hashmap_get(&map, keys[i]) == values[i]);
-                break;
-        }
-    }
-
-    hashmap_destroy(&map);
+    json_free(val);
 }