3. Foreign Rust References🔗

This chapter previews foreign Rust references backed by a live language-server lookup. Resolved references render a compact Rust source link and a grouped Rust code panel fetched from the location returned by rust-analyzer.

Definition3.1

XL∃∀Nused by 0

The Collatz step sends an even number to half of itself and an odd number to 3n + 1.

Rust code for Definition3.1

collatz_stepsource

/// Return the next value in the Collatz orbit.
pub fn collatz_step(n: u64) -> u64 {
    if n % 2 == 0 {
        n / 2
    } else {
        3 * n + 1
    }
}

Definition3.2

XL∃∀Nused by 0

The bounded search version measures each orbit and checks a finite prefix of the Collatz conjecture.

Rust code for Definition3.2

collatz_total_stopping_timesource

/// Count how long the Collatz orbit of `n` takes to reach `1`.
pub fn collatz_total_stopping_time(mut n: u64) -> u64 {
    let mut steps = 0;
    while n > 1 {
        n = collatz_step(n);
        steps += 1;
    }
    steps
}

collatz_holds_belowsource

/// Check the Collatz conjecture by exhaustive search below a finite bound.
pub fn collatz_holds_below(limit: u64) -> bool {
    for n in 1..=limit {
        if collatz_total_stopping_time(n) > 10_000 {
            return false;
        }
    }
    true
}

Definition3.3

XL∃∀Nused by 0

Constants and statics live in Rust's value namespace, so the current synthetic lookup strategy resolves them like functions.

Rust code for Definition3.3

COLLATZ_LIMITsource

/// Default finite bound used by the preview search.
pub const COLLATZ_LIMIT: u64 = 10_000;

COLLATZ_STARTsource

/// A familiar starting value with a long but finite Collatz orbit.
pub static COLLATZ_START: u64 = 27;

Definition3.4

XL∃∀Nused by 0

A mixed attachment keeps the resolved reference and reports the missing one as a warning.

Rust code for Definition3.4

Resolvedcollatz_step
Unresolvedcollatz_typo: language server did not return a definition location

collatz_stepsource

/// Return the next value in the Collatz orbit.
pub fn collatz_step(n: u64) -> u64 {
    if n % 2 == 0 {
        n / 2
    } else {
        3 * n + 1
    }
}

Definition3.5

XL∃∀Nused by 0

A completely missing Rust symbol produces an unresolved reference without a code panel.

Rust code for Definition3.5

Unresolvedmissing_collatz_symbol: language server did not return a definition location

Definition3.6

XL∃∀Nused by 0

These names exercise Rust's type namespace. They are included as a live preview of the current synthetic lookup shape, which is still optimized for value references.

Rust code for Definition3.6

CollatzRecordsource

/// A small record for Collatz computations.
pub struct CollatzRecord {
    pub start: u64,
    pub steps: u64,
}

CollatzParitysource

/// The parity branch selected by one Collatz step.
pub enum CollatzParity {
    Even,
    Odd,
}

CollatzMeasuresource

/// A trait shape included to exercise Rust's type namespace.
pub trait CollatzMeasure {
    fn measure(&self) -> u64;
}

CollatzValuesource

/// A type alias included to exercise Rust's type namespace.
pub type CollatzValue = u64;