54 lines
1.5 KiB
Rust
54 lines
1.5 KiB
Rust
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use crate::renderer::context_element::ContextElement;
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use crate::renderer::WalkError;
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enum WalkResult<'a> {
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NoWalk,
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PartialWalk,
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FullyWalked(&'a dyn ContextElement),
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}
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fn walk_path_from_single_level<'a>(
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context: &'a dyn ContextElement,
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path: &Vec<&str>,
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) -> WalkResult<'a> {
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if path.is_empty() {
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return WalkResult::FullyWalked(context);
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}
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let mut walk_failure = WalkResult::NoWalk;
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let mut output = context;
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for elem in path.iter() {
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let new_val = output.walk(elem);
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match output.walk(elem) {
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Err(WalkError::CantWalk { .. }) => {
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return walk_failure;
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}
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Ok(new_val) => {
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walk_failure = WalkResult::PartialWalk;
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output = new_val;
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}
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}
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}
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WalkResult::FullyWalked(output)
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}
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pub fn walk_path<'a>(
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breadcrumbs: &Vec<&'a dyn ContextElement>,
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path: &'a Vec<&str>,
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) -> Result<&'a dyn ContextElement, WalkError> {
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for context in breadcrumbs.iter().rev() {
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match walk_path_from_single_level(*context, path) {
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// If no walking was done at all, keep looping
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WalkResult::NoWalk => {}
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// If we partially walked then stop trying to find
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// anything
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WalkResult::PartialWalk => {
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return Err(WalkError::CantWalk);
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}
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WalkResult::FullyWalked(new_context) => return Ok(new_context),
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}
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}
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Err(WalkError::CantWalk)
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}
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