ClickHouse JSON Boolean Extractor (Functions/visitParamExtractBool.cpp)

Extracts boolean true or false values from JSON fields within ClickHouse queries. Reuse when parsing JSON strings inside database analytics engines.

// Source: https://github.com/ClickHouse/ClickHouse | License: Apache-2.0 | Copyright 2016-2026 ClickHouse, Inc
// Provided via justclaw.it.com; keep this notice with the code.
#include <Functions/FunctionFactory.h>
#include <Functions/FunctionsVisitParam.h>
#include <Functions/FunctionsStringSearch.h>


namespace DB
{

struct ExtractBool
{
    using ResultType = UInt8;

    static UInt8 extract(const UInt8 * begin, const UInt8 * end)
    {
        return begin + 4 <= end && 0 == strncmp(reinterpret_cast<const char *>(begin), "true", 4);
    }
};

struct NameSimpleJSONExtractBool { static constexpr auto name = "simpleJSONExtractBool"; };
using FunctionSimpleJSONExtractBool = FunctionsStringSearch<ExtractParamImpl<NameSimpleJSONExtractBool, ExtractBool>>;

REGISTER_FUNCTION(VisitParamExtrac

... (truncated -- full source via MCP)