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//! DeepMerge implementation for toml::Value
use crate::policy::*;
use crate::{DeepMerge, MergeOutcome};
use toml::Value;
use std::mem;
impl<P: Policy> DeepMerge<P> for Value {
fn merge_with_policy(&mut self, other: Self, policy: &P) {
// Check condition early
match policy.when_condition() {
Condition::Always => {},
Condition::NonEmpty => {
match &other {
Value::Array(arr) if arr.is_empty() => return,
Value::Table(tbl) if tbl.is_empty() => return,
Value::String(s) if s.is_empty() => return,
_ => {},
}
},
Condition::NonDefault => {
match &other {
Value::Boolean(false) => return,
Value::Integer(0) => return,
Value::Float(f) if *f == 0.0 => return,
Value::String(s) if s.is_empty() => return,
Value::Array(arr) if arr.is_empty() => return,
Value::Table(tbl) if tbl.is_empty() => return,
_ => {},
}
},
Condition::Some => {
// TOML doesn't have null, so this doesn't apply
},
Condition::Changed => {
if self == &other {
return;
}
},
Condition::ChangedBy(_) => {
// Without custom key extractors, fall back to equality
if self == &other {
return;
}
},
}
// Apply merge based on types
match (self, other) {
// Table merging uses map policies
(Value::Table(dst), Value::Table(src)) => {
match policy.map_merge() {
MapMerge::Overlay => {
// Recursively merge matching keys, add new keys
for (k, v) in src.into_iter() {
match dst.get_mut(&k) {
Some(dst_val) => {
dst_val.merge_with_policy(v, policy);
},
None => {
dst.insert(k, v);
}
}
}
},
MapMerge::Union => {
// Add all keys from src, overwriting on conflict
dst.extend(src);
},
MapMerge::Left => {
// Keep only left entries
},
MapMerge::Right => {
// Replace with right entries
*dst = src;
},
}
},
// Array merging uses sequence policies
(Value::Array(dst), Value::Array(src)) => {
match policy.sequence_merge() {
SequenceMerge::Append | SequenceMerge::Extend => {
dst.extend(src);
},
SequenceMerge::Prepend => {
let mut result = src;
result.extend(mem::take(dst));
*dst = result;
},
SequenceMerge::Union => {
// O(n^2) deduplication by equality - acceptable for config-sized arrays
for v in src {
if !dst.iter().any(|existing| existing == &v) {
dst.push(v);
}
}
},
SequenceMerge::Intersect => {
// Keep only elements that exist in both
let src_set = &src; // Keep reference for comparison
dst.retain(|x| src_set.iter().any(|y| y == x));
},
}
},
// String merging uses string policies
(Value::String(dst), Value::String(src)) => {
match policy.string_merge() {
StringMerge::Replace => *dst = src,
StringMerge::Keep => {},
StringMerge::Concat => dst.push_str(&src),
StringMerge::ConcatWithSep(sep) => {
if !dst.is_empty() && !src.is_empty() {
dst.push_str(sep);
}
dst.push_str(&src);
},
}
},
// Boolean merging uses bool policies
(Value::Boolean(dst), Value::Boolean(src)) => {
match policy.bool_merge() {
BoolMerge::Replace => *dst = src,
BoolMerge::Keep => {},
BoolMerge::TrueWins => *dst = *dst || src,
BoolMerge::FalseWins => *dst = *dst && src,
}
},
// Integer merging uses number policies
(Value::Integer(dst), Value::Integer(src)) => {
match policy.number_merge() {
NumberMerge::Replace => *dst = src,
NumberMerge::Keep => {},
NumberMerge::Sum => *dst = dst.saturating_add(src),
NumberMerge::Max => *dst = (*dst).max(src),
NumberMerge::Min => *dst = (*dst).min(src),
}
},
// Float merging uses number policies
(Value::Float(dst), Value::Float(src)) => {
match policy.number_merge() {
NumberMerge::Replace => *dst = src,
NumberMerge::Keep => {},
NumberMerge::Sum => *dst = *dst + src,
NumberMerge::Max => *dst = dst.max(src),
NumberMerge::Min => *dst = dst.min(src),
}
},
// Mixed numeric types - convert to float
(dst @ Value::Integer(_), Value::Float(src)) => {
if let Value::Integer(dst_val) = dst {
match policy.number_merge() {
NumberMerge::Replace => *dst = Value::Float(src),
NumberMerge::Keep => {},
NumberMerge::Sum => *dst = Value::Float(*dst_val as f64 + src),
NumberMerge::Max => *dst = Value::Float((*dst_val as f64).max(src)),
NumberMerge::Min => *dst = Value::Float((*dst_val as f64).min(src)),
}
}
},
(dst @ Value::Float(_), Value::Integer(src)) => {
if let Value::Float(dst_val) = dst {
match policy.number_merge() {
NumberMerge::Replace => *dst = Value::Integer(src),
NumberMerge::Keep => {},
NumberMerge::Sum => *dst_val = *dst_val + src as f64,
NumberMerge::Max => *dst_val = dst_val.max(src as f64),
NumberMerge::Min => *dst_val = dst_val.min(src as f64),
}
}
},
// Datetime as scalar - for now just replace/keep
// Future: could add max/min for datetime comparison
(dst @ Value::Datetime(_), Value::Datetime(src)) => {
match policy.scalar_action() {
ScalarAction::Replace | ScalarAction::Merge => *dst = Value::Datetime(src),
ScalarAction::Keep => {},
}
},
// Mismatched types: use scalar action
(dst, src) => {
match policy.scalar_action() {
ScalarAction::Replace => *dst = src,
ScalarAction::Keep => {},
ScalarAction::Merge => {
// For incompatible types, merge means replace
*dst = src;
}
}
}
}
}
fn merge_with_policy_reporting(&mut self, other: Self, policy: &P) -> MergeOutcome {
// Check if values are equal before merging
let unchanged = self == &other;
// Check condition early
match policy.when_condition() {
Condition::Always => {},
Condition::NonEmpty => {
match &other {
Value::Array(arr) if arr.is_empty() => return MergeOutcome::Unchanged,
Value::Table(tbl) if tbl.is_empty() => return MergeOutcome::Unchanged,
Value::String(s) if s.is_empty() => return MergeOutcome::Unchanged,
_ => {},
}
},
Condition::NonDefault => {
match &other {
Value::Boolean(false) => return MergeOutcome::Unchanged,
Value::Integer(0) => return MergeOutcome::Unchanged,
Value::Float(f) if *f == 0.0 => return MergeOutcome::Unchanged,
Value::String(s) if s.is_empty() => return MergeOutcome::Unchanged,
Value::Array(arr) if arr.is_empty() => return MergeOutcome::Unchanged,
Value::Table(tbl) if tbl.is_empty() => return MergeOutcome::Unchanged,
_ => {},
}
},
Condition::Some => {
// TOML doesn't have null
},
Condition::Changed => {
if unchanged {
return MergeOutcome::Unchanged;
}
},
Condition::ChangedBy(_) => {
if unchanged {
return MergeOutcome::Unchanged;
}
},
}
// Store original for comparison
let original = self.clone();
// Perform merge
self.merge_with_policy(other, policy);
// Check if anything changed
if &original == self {
MergeOutcome::Unchanged
} else {
MergeOutcome::Changed
}
}
}