Initial commit

json.c

@@ -0,0 +1,193 @@
+#include "json.h"
+
+#include <assert.h>
+
+#define UNREACHABLE() assert(false)
+
+Json json_init(FILE* stream, Whitespace whitespace)
+{
+    return (Json){
+        .stream = stream,
+        .whitespace = whitespace,
+        .indent_level = 0,
+        .next_punctuation = BEGINNING,
+    };
+}
+
+void json_free(Json* json)
+{
+}
+
+void begin_value(Json* json);
+void end_value(Json* json);
+void push_indentation(Json* json);
+void pop_indentation(Json* json);
+void indent(Json* json);
+
+void json_begin_array(Json* json)
+{
+    begin_value(json);
+    putc('[', json->stream);
+    push_indentation(json);
+    json->next_punctuation = NONE;
+}
+
+void json_end_array(Json* json)
+{
+    pop_indentation(json);
+    switch (json->next_punctuation) {
+    case NONE:
+        break;
+    case COMMA:
+        indent(json);
+        break;
+    case BEGINNING:
+    case COLON:
+        UNREACHABLE();
+    }
+    putc(']', json->stream);
+    end_value(json);
+}
+
+void json_begin_object(Json* json)
+{
+    begin_value(json);
+    putc('{', json->stream);
+    push_indentation(json);
+    json->next_punctuation = NONE;
+}
+
+void json_end_object(Json* json)
+{
+    pop_indentation(json);
+    switch (json->next_punctuation) {
+    case NONE:
+        break;
+    case COMMA:
+        indent(json);
+        break;
+    case BEGINNING:
+    case COLON:
+        UNREACHABLE();
+    }
+    putc('}', json->stream);
+    end_value(json);
+}
+
+void json_add_object_field(Json* json, const char* key)
+{
+    begin_value(json);
+    fprintf(json->stream, "\"%s\"", key);
+    json->next_punctuation = COLON;
+}
+
+void json_add_string(Json* json, const char* value)
+{
+    begin_value(json);
+    fprintf(json->stream, "\"%s\"", value);
+    end_value(json);
+}
+
+void json_add_long(Json* json, long value)
+{
+    begin_value(json);
+    fprintf(json->stream, "%ld", value);
+    end_value(json);
+}
+
+void json_add_double(Json* json, double value)
+{
+    begin_value(json);
+    fprintf(json->stream, "%f", value);
+    end_value(json);
+}
+
+void json_add_bool(Json* json, bool value)
+{
+    begin_value(json);
+    const char* s;
+    if (value) {
+        s = "true";
+    } else {
+        s = "false";
+    }
+    fputs(s, json->stream);
+    end_value(json);
+}
+
+void json_add_null(Json* json)
+{
+    begin_value(json);
+    fputs("null", json->stream);
+    end_value(json);
+}
+
+void begin_value(Json* json)
+{
+    switch (json->next_punctuation) {
+    case BEGINNING:
+        break;
+    case NONE:
+        indent(json);
+        break;
+    case COMMA:
+        fputc(',', json->stream);
+        indent(json);
+        break;
+    case COLON:
+        putc(':', json->stream);
+        if (json->whitespace != MINIFIED) {
+            fputc(' ', json->stream);
+        }
+        break;
+    }
+}
+
+void end_value(Json* json)
+{
+    json->next_punctuation = COMMA;
+}
+
+void push_indentation(Json* json)
+{
+    json->indent_level += 1;
+}
+
+void pop_indentation(Json* json)
+{
+    json->indent_level -= 1;
+}
+
+void indent(Json* json)
+{
+    char indent_char = ' ';
+    int n;
+    switch (json->whitespace) {
+    case MINIFIED:
+        return;
+    case INDENT_1:
+        n = 1 * json->indent_level;
+        break;
+    case INDENT_2:
+        n = 2 * json->indent_level;
+        break;
+    case INDENT_3:
+        n = 3 * json->indent_level;
+        break;
+    case INDENT_4:
+        n = 4 * json->indent_level;
+        break;
+    case INDENT_8:
+        n = 8 * json->indent_level;
+        break;
+    case INDENT_TAB:
+        indent_char = '\t';
+        n = json->indent_level;
+        break;
+    }
+    putc('\n', json->stream);
+    for (int i = 0; i < n; i++) {
+        putc(indent_char, json->stream);
+    }
+}
+