41 lines
1.3 KiB
Plaintext
41 lines
1.3 KiB
Plaintext
:sig
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String DValue::to_string(String default_value = "") const
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:params
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default_value : returned when the node holds no usable text
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return value : the scalar content as text, or `default_value`
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:see
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>types
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0_DValue
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to_s64
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to_f64
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to_bool
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to_json
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get_by_path
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:content
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Reads a `DValue` value as text. This is a read accessor: it is `const`, never creates or modifies nodes, and dereferences internal references automatically.
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`default_value` is returned when the value is missing or not text-convertible:
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- the node is unset or holds an empty string (a missing key read via `get_by_path()` looks exactly like this)
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- the node is map-shaped (use `json_encode()` or `to_stringmap()` for those)
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- the node is an unresolvable reference
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Other scalar kinds convert instead of falling back: `f64` values format with six decimal places (`std::to_string`), `bool` values become `(true)` / `(false)`, and pointers format as their numeric address.
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## Example
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```cpp
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String title = context.props["title"].to_string("Untitled");
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String theme = context.cfg.get_by_path("theme/key").to_string("light");
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```
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The default argument replaces the older `first(x.to_string(), "fallback")` idiom.
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## Related Concepts
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- PHP: `$value ?? 'fallback'` / `strval()`
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- JavaScript: `String(value || "fallback")`
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