rsaeb 0.10.1

A no_std + alloc interpreter for A=B ordered rewrite programs.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142

use alloc::vec::Vec;

use crate::allocation::AllocationError;
use crate::bytes::PayloadByteCount;
use crate::inspect::{RuleAction, RuleAnchor, RulePosition, RuleRepeat, RuleView};
use crate::materialized::{MaterializedBytes, OwnedRuleWitnessPayloadDomain};
use crate::source::SourceLineNumber;

/// Parsed payload bytes retained by owned execution rule witnesses.
#[derive(Debug, PartialEq, Eq)]
pub struct OwnedRulePayload {
    /// Owned bytes tagged as an owned execution rule witness payload.
    bytes: MaterializedBytes<OwnedRuleWitnessPayloadDomain>,
}

impl OwnedRulePayload {
    /// Borrow the materialized payload bytes.
    #[must_use]
    pub fn as_slice(&self) -> &[u8] {
        self.bytes.as_slice()
    }

    /// Consumes this value and returns the materialized host bytes.
    #[must_use]
    pub fn into_raw_bytes(self) -> Vec<u8> {
        self.bytes.into_raw_bytes()
    }

    /// Materialized payload length in bytes.
    #[must_use]
    pub fn byte_count(&self) -> PayloadByteCount {
        PayloadByteCount::new(self.bytes.len())
    }

    /// Returns whether this materialized payload contains no bytes.
    #[must_use]
    pub fn is_empty(&self) -> bool {
        self.bytes.is_empty()
    }
}

/// Owned parsed-rule witness retained by owned execution transitions.
#[derive(Debug, PartialEq, Eq)]
pub struct OwnedRuleWitness {
    /// Program-local parsed-rule position.
    position: RulePosition,
    /// One-based source line number.
    line_number: SourceLineNumber,
    /// Rule repeat policy.
    repeat: RuleRepeat,
    /// Rule match anchor.
    anchor: RuleAnchor,
    /// Materialized left-side match payload.
    lhs: OwnedRulePayload,
    /// Materialized right-side action payload.
    action: RuleAction<OwnedRulePayload>,
}

impl OwnedRuleWitness {
    /// Materializes an owned witness from the borrowed parsed rule boundary.
    ///
    /// # Errors
    ///
    /// Returns `AllocationError` if retaining the parsed rule payload bytes for
    /// an owned execution transition cannot allocate.
    pub(crate) fn from_rule_view(rule: RuleView<'_>) -> Result<Self, AllocationError> {
        let lhs = materialize_owned_rule_payload(rule.lhs())?;
        let action = match rule.action() {
            RuleAction::Replace(payload) => {
                RuleAction::Replace(materialize_owned_rule_payload(payload)?)
            }
            RuleAction::MoveStart(payload) => {
                RuleAction::MoveStart(materialize_owned_rule_payload(payload)?)
            }
            RuleAction::MoveEnd(payload) => {
                RuleAction::MoveEnd(materialize_owned_rule_payload(payload)?)
            }
            RuleAction::Return(payload) => {
                RuleAction::Return(materialize_owned_rule_payload(payload)?)
            }
        };

        Ok(Self {
            position: rule.position(),
            line_number: rule.line_number(),
            repeat: rule.repeat(),
            anchor: rule.anchor(),
            lhs,
            action,
        })
    }

    /// Program-local parsed-rule position.
    #[must_use]
    pub const fn position(&self) -> RulePosition {
        self.position
    }

    /// One-based source line number.
    #[must_use]
    pub const fn line_number(&self) -> SourceLineNumber {
        self.line_number
    }

    /// Rule repeat policy.
    #[must_use]
    pub const fn repeat(&self) -> RuleRepeat {
        self.repeat
    }

    /// Rule match anchor.
    #[must_use]
    pub const fn anchor(&self) -> RuleAnchor {
        self.anchor
    }

    /// Materialized left-side match payload.
    #[must_use]
    pub const fn lhs(&self) -> &OwnedRulePayload {
        &self.lhs
    }

    /// Materialized right-side action payload.
    #[must_use]
    pub const fn action(&self) -> &RuleAction<OwnedRulePayload> {
        &self.action
    }
}

/// Materializes a payload for the owned execution rule-witness boundary.
///
/// # Errors
///
/// Returns `AllocationError` if the payload bytes cannot be retained for an
/// owned execution rule witness.
fn materialize_owned_rule_payload(
    payload: crate::inspect::PayloadView<'_>,
) -> Result<OwnedRulePayload, AllocationError> {
    Ok(OwnedRulePayload {
        bytes: MaterializedBytes::from_owned_rule_payload(payload)?,
    })
}