Struct SaveOptions 

pub struct SaveOptions {
    pub parser: &'static str,
    pub lexer_type: String,
    pub ambiguity: &'static str,
    pub priority: Option<&'static str>,
    pub keep_all_tokens: bool,
    pub maybe_placeholders: bool,
    pub ordered_sets: bool,
    pub use_bytes: bool,
    pub g_regex_flags: u32,
    pub translate_python_regex: bool,
    pub propagate_positions: bool,
    pub start: Vec<String>,
}

The scalar, compile-invariant options that populate data.options. The callable/hook options (transformer, postlex, lexer_callbacks, edit_terminals) are deliberately absent — they are re-supplied at load (Lark’s _LOAD_ALLOWED_OPTIONS) and cannot cross a portable JSON boundary; the Python binding layers them into a pickle envelope wrapping this JSON.

Fields

parser: &'static str

"lalr" — the only parser save supports (non-LALR is rejected by Lark).

lexer_type: String

The resolved lexer name (Lark round-trips the resolved value, not auto).

ambiguity: &'static str

"auto" / "resolve" / "explicit" (Lark serializes Resolve as auto).

priority: Option<&'static str>

"auto" / "normal" / "invert", or None for Lark’s priority=None.

keep_all_tokens: bool

maybe_placeholders: bool

ordered_sets: bool

use_bytes: bool

g_regex_flags: u32

translate_python_regex: bool

Whether the terminals are read in Python’s re dialect. Rides the wire beside g_regex_flags for the same reason: it decides what the saved patterns MEAN, and a load that guessed it would compile a different language from the one that was saved.

propagate_positions: bool

start: Vec<String>