Scalar style helpers

These functions are used by the emitter to choose a scalar style when a scalar does not have it set. More...

Functions
bool	c4::yml::scalar_style_query_squo (csubstr scalar) noexcept
	query whether a scalar can be encoded using single quotes. More...
bool	c4::yml::scalar_style_query_plain_flow (csubstr scalar) noexcept
	query whether a scalar can be encoded using plain style while in flow mode. More...
bool	c4::yml::scalar_style_query_plain_block (csubstr scalar) noexcept
	query whether a scalar can be encoded using plain style while in block mode. More...
NodeType	c4::yml::scalar_style_choose_flow (csubstr scalar) noexcept
	choose a YAML scalar style based on the scalar's contents, while in flow mode. More...
NodeType	c4::yml::scalar_style_choose_block (csubstr scalar) noexcept
	choose a YAML scalar style based on the scalar's contents, while in block mode. More...
NodeType	c4::yml::scalar_style_choose_json (csubstr scalar) noexcept
	choose a json scalar style based on the scalar's contents More...

Detailed Description

These functions are used by the emitter to choose a scalar style when a scalar does not have it set.

Function Documentation

bool c4::yml::scalar_style_query_squo ( csubstr  scalar )

noexcept

query whether a scalar can be encoded using single quotes.

It may not be possible, notably when there is leading whitespace after a newline.

Definition at line 15 of file scalar_style.cpp.

Referenced by c4::yml::scalar_style_choose_block(), and c4::yml::scalar_style_choose_flow().

{
    // see https://www.yaml.info/learn/quote.html#noplain
    // cannot have leading whitespace after a newline
    for(size_t i = 0; i < scalar.len; ++i)
    {
        if(scalar.str[i] == '\n' && i + 1 < scalar.len)
        {
            char next = scalar.str[i + 1];
            if(next == ' ' || next == '\t')
                return false;
        }
    }
    return true;
}

bool c4::yml::scalar_style_query_plain_flow ( csubstr  scalar )

noexcept

query whether a scalar can be encoded using plain style while in flow mode.

Plain scalars [have more constraints in flow mode than in block mode](https://www.yaml.info/learn/quote.html#noplain). scalar_style_query_plain_block() is the block mode analogous function.

Definition at line 51 of file scalar_style.cpp.

Referenced by c4::yml::scalar_style_choose_flow().

{
    // see https://www.yaml.info/learn/quote.html#noplain
    if(!scalar.len)
        return !scalar.str;
    // first
    switch(scalar.str[0])
    {
    case ' ': case '\n': case '\t': case '\r':
    case '!': case '&': case '*': case ',':
    case '"': case '\'': case '|': case '>':
    case '{': case '}': case '[': case ']':
    case '#': case '`': case '%': case '@':
        return false;
    case '-': case ':': case '?':
        if(scalar.len == 1 || (scalar.str[1] == ' ' || scalar.str[1] == '\t'))
            return false;
        break;
    }
    // bulk
    for(size_t i = 1; i + 1 < scalar.len; ++i)
    {
        switch(scalar.str[i])
        {
        case ',': case '{': case '}': case '[': case ']':
            return false;
        case ':': case '#':
            if(!is_valid_bulk_(scalar, i))
                return false;
            break;
        }
    }
    // last
    if(scalar.len > 1)
    {
        switch(scalar.back())
        {
        case ' ': case '\n': case '\t': case '\r':
        case ',':
        case '{': case '}':
        case '[': case ']':
        case '#':
        case ':':
            return false;
        }
    }
    return true;
}

bool c4::yml::scalar_style_query_plain_block ( csubstr  scalar )

noexcept

query whether a scalar can be encoded using plain style while in block mode.

Plain scalars [have more constraints in flow mode than in block mode](https://www.yaml.info/learn/quote.html#noplain). scalar_style_query_plain_flow() is the flow mode analogous function.

Definition at line 101 of file scalar_style.cpp.

Referenced by c4::yml::scalar_style_choose_block().

{
    // see https://www.yaml.info/learn/quote.html#noplain
    if(!scalar.len)
        return !scalar.str;
    // first
    switch(scalar.str[0])
    {
    case ' ': case '\n': case '\t': case '\r':
    case '!': case '&': case '*': case ',':
    case '"': case '\'': case '|': case '>':
    case '{': case '}': case '[': case ']':
    case '#': case '`': case '%': case '@':
        return false;
    case '-': case ':': case '?':
        if (scalar.len == 1 || (scalar.str[1] == ' ' || scalar.str[1] == '\t'))
            return false;
        break;
    }
    // bulk
    for(size_t i = 1; i + 1 < scalar.len; ++i)
    {
        switch(scalar.str[i])
        {
        case ':': case '#':
            if(!is_valid_bulk_(scalar, i))
                return false;
            break;
        }
    }
    // last
    if(scalar.len > 1)
    {
        switch(scalar.back())
        {
        case ' ': case '\n': case '\t': case '\r':
        case '#':
        case ':':
            return false;
        }
    }
    return true;
}

NodeType c4::yml::scalar_style_choose_flow ( csubstr  scalar )

inlinenoexcept

choose a YAML scalar style based on the scalar's contents, while in flow mode.

Plain scalars [have more constraints in flow mode than in block mode](https://www.yaml.info/learn/quote.html#noplain). scalar_style_choose_block() is the block mode analogous function.

Definition at line 46 of file scalar_style.hpp.

{
    if(scalar.len)
    {
        if(scalar_style_query_plain_flow(scalar))
            return SCALAR_PLAIN;
        else if(scalar_style_query_squo(scalar))
            return SCALAR_SQUO;
        return SCALAR_DQUO;
    }
    return scalar.str ? SCALAR_SQUO : SCALAR_PLAIN;
}

NodeType c4::yml::scalar_style_choose_block ( csubstr  scalar )

noexcept

choose a YAML scalar style based on the scalar's contents, while in block mode.

Plain scalars [have more constraints in flow mode than in block mode](https://www.yaml.info/learn/quote.html#noplain). scalar_style_choose_block() is the flow mode analogous function.

Definition at line 146 of file scalar_style.cpp.

{
    if(scalar.len)
    {
        if(scalar_style_query_plain_block(scalar))
            return SCALAR_PLAIN;
        RYML_ASSERT_BASIC_(scalar_style_query_squo(scalar)
                           && "if this assertion fires, please submit an issue!");
        return SCALAR_SQUO;
    }
    return scalar.str ? SCALAR_SQUO : SCALAR_PLAIN;
}

NodeType c4::yml::scalar_style_choose_json ( csubstr  scalar )

noexcept

choose a json scalar style based on the scalar's contents

Definition at line 160 of file scalar_style.cpp.

{
    // do not quote numbers or special scalars
    return scalar_is_plain_number_json(scalar)
        || scalar_is_special_json(scalar) ? SCALAR_PLAIN : SCALAR_DQUO;
}