agent_first_data/document/format/
toml.rs

1//! TOML format backend (format-preserving via toml_edit).
2
3use crate::document::{DocumentError, DocumentResult, Value};
4
5/// Edit an existing scalar item in a TOML document without reserializing the
6/// surrounding document. Comments, ordering, whitespace, and datetime syntax
7/// outside the target remain owned by `toml_edit::DocumentMut`.
8pub fn set_preserving(content: &str, path: &str, value: &Value) -> DocumentResult<String> {
9    let segments = crate::document::parse_path(path)?;
10    if segments.iter().any(|segment| segment.contains(['.', '\\'])) {
11        return Err(DocumentError::UnsupportedOperation {
12            format: "TOML".to_string(),
13            operation: "set".to_string(),
14            detail: "escaped TOML keys are not supported by the current document path adapter"
15                .to_string(),
16        });
17    }
18    let mut document =
19        content
20            .parse::<toml_edit::DocumentMut>()
21            .map_err(|error| DocumentError::ParseError {
22                format: "TOML".to_string(),
23                detail: error.to_string(),
24            })?;
25    let item = toml_item(value)?;
26    let (last, parents) = segments.split_last().ok_or(DocumentError::EmptyPath)?;
27    let mut current = document.as_item_mut();
28    for parent in parents {
29        // Auto-create a missing intermediate table so a sparse config can grow
30        // (`set imap.host` when `[imap]` is absent), matching `set_path`.
31        // toml_edit returns `Some(Item::None)` for absent keys, so treat that as
32        // a genuinely missing parent rather than a navigable node.
33        {
34            let table =
35                current
36                    .as_table_like_mut()
37                    .ok_or_else(|| DocumentError::UnsupportedOperation {
38                        format: "TOML".to_string(),
39                        operation: "set".to_string(),
40                        detail: "cannot address a key inside a non-table TOML value".to_string(),
41                    })?;
42            if table.get(parent).filter(|item| !item.is_none()).is_none() {
43                let mut created = toml_edit::Table::new();
44                created.set_implicit(true);
45                table.insert(parent, toml_edit::Item::Table(created));
46            }
47        }
48        current = current
49            .get_mut(parent)
50            .filter(|item| !item.is_none())
51            .ok_or_else(|| DocumentError::PathNotFound {
52                path: path.to_string(),
53            })?;
54    }
55    let table = current
56        .as_table_like_mut()
57        .ok_or_else(|| DocumentError::UnsupportedOperation {
58            format: "TOML".to_string(),
59            operation: "set".to_string(),
60            detail: "cannot address a key inside a non-table TOML value".to_string(),
61        })?;
62    match table.get_mut(last).filter(|item| !item.is_none()) {
63        Some(target) => {
64            if !target.is_value() {
65                return Err(DocumentError::UnsupportedOperation {
66                    format: "TOML".to_string(),
67                    operation: "set".to_string(),
68                    detail: "only existing scalar TOML values are supported by the document editor"
69                        .to_string(),
70                });
71            }
72            let decor = target.as_value().map(|value| value.decor().clone());
73            *target = item;
74            if let (Some(decor), Some(value)) = (decor, target.as_value_mut()) {
75                *value.decor_mut() = decor;
76            }
77        }
78        // New leaf: append into the (existing) parent table. Intermediate parent
79        // tables are not auto-created — a missing parent fails above.
80        None => {
81            table.insert(last, item);
82        }
83    }
84    Ok(document.to_string())
85}
86
87/// Remove an existing TOML item through `toml_edit`, retaining document decor.
88pub fn unset_preserving(content: &str, path: &str) -> DocumentResult<String> {
89    let segments = crate::document::parse_path(path)?;
90    if segments.iter().any(|segment| segment.contains(['.', '\\'])) {
91        return Err(DocumentError::UnsupportedOperation {
92            format: "TOML".to_string(),
93            operation: "unset".to_string(),
94            detail: "escaped TOML keys are not supported by the current document path adapter"
95                .to_string(),
96        });
97    }
98    let (last, parents) = segments.split_last().ok_or(DocumentError::EmptyPath)?;
99    let mut document =
100        content
101            .parse::<toml_edit::DocumentMut>()
102            .map_err(|error| DocumentError::ParseError {
103                format: "TOML".to_string(),
104                detail: error.to_string(),
105            })?;
106    let mut current = document.as_item_mut();
107    for parent in parents {
108        current = current
109            .get_mut(parent)
110            .ok_or_else(|| DocumentError::PathNotFound {
111                path: path.to_string(),
112            })?;
113    }
114    let table = current
115        .as_table_mut()
116        .ok_or_else(|| DocumentError::UnsupportedOperation {
117            format: "TOML".to_string(),
118            operation: "unset".to_string(),
119            detail: "only table entries can be removed by the current TOML editor".to_string(),
120        })?;
121    if table.remove(last).is_none() {
122        return Err(DocumentError::PathNotFound {
123            path: path.to_string(),
124        });
125    }
126    Ok(document.to_string())
127}
128
129fn toml_item(value: &Value) -> DocumentResult<toml_edit::Item> {
130    match value {
131        Value::Null => Err(DocumentError::UnsupportedOperation {
132            format: "TOML".to_string(),
133            operation: "set".to_string(),
134            detail: "TOML has no null value".to_string(),
135        }),
136        Value::Bool(value) => Ok(toml_edit::value(*value)),
137        Value::Integer(value) => Ok(toml_edit::value(*value)),
138        Value::Unsigned(value) => i64::try_from(*value).map(toml_edit::value).map_err(|_| {
139            DocumentError::UnsupportedOperation {
140                format: "TOML".to_string(),
141                operation: "set".to_string(),
142                detail: "unsigned integer exceeds TOML i64 range".to_string(),
143            }
144        }),
145        Value::Float(value) if value.is_finite() => Ok(toml_edit::value(*value)),
146        Value::Float(_) => Err(DocumentError::UnsupportedOperation {
147            format: "TOML".to_string(),
148            operation: "set".to_string(),
149            detail: "non-finite TOML float is not representable".to_string(),
150        }),
151        // A `Value::Number` literal is float-shaped (has a `.`/`e`) or
152        // integer-shaped (does not); an integer-shaped one only exists
153        // because it overflows `u64`, which also overflows TOML's 64-bit
154        // integer grammar, so it can never be written. A float-shaped one
155        // parses to `f64` cleanly (it already passed JSON-number syntax
156        // validation) and writes like any other TOML float — TOML floats
157        // are canonically `f64` at the format level, so this is not a
158        // fidelity regression versus `Value::Float` above.
159        Value::Number(text) if value.is_float() => text
160            .parse::<f64>()
161            .ok()
162            .filter(|value| value.is_finite())
163            .map(toml_edit::value)
164            .ok_or_else(|| DocumentError::UnsupportedOperation {
165                format: "TOML".to_string(),
166                operation: "set".to_string(),
167                detail: format!("float literal `{text}` is not representable in TOML"),
168            }),
169        Value::Number(text) => Err(DocumentError::UnsupportedOperation {
170            format: "TOML".to_string(),
171            operation: "set".to_string(),
172            detail: format!("integer literal `{text}` exceeds TOML's 64-bit integer range"),
173        }),
174        Value::String(value) => Ok(toml_edit::value(value.clone())),
175        Value::Array(_) | Value::Object(_) => Err(DocumentError::UnsupportedOperation {
176            format: "TOML".to_string(),
177            operation: "set".to_string(),
178            detail: "collection mutation requires a dedicated TOML editor".to_string(),
179        }),
180    }
181}
182
183pub fn load(content: &str) -> DocumentResult<Value> {
184    toml::from_str::<toml::Value>(content)
185        .map(value_to_our_value)
186        .map_err(|e| DocumentError::ParseError {
187            format: "TOML".to_string(),
188            detail: e.to_string(),
189        })
190}
191
192pub fn save(value: &Value) -> DocumentResult<String> {
193    let toml_val = our_value_to_toml_value(value)?;
194    toml::to_string_pretty(&toml_val).map_err(|e| DocumentError::ParseError {
195        format: "TOML".to_string(),
196        detail: e.to_string(),
197    })
198}
199
200fn value_to_our_value(v: toml::Value) -> Value {
201    match v {
202        toml::Value::Boolean(b) => Value::Bool(b),
203        toml::Value::Integer(i) => Value::Integer(i),
204        toml::Value::Float(f) => Value::Float(f),
205        toml::Value::String(s) => Value::String(s),
206        toml::Value::Array(a) => Value::Array(a.into_iter().map(value_to_our_value).collect()),
207        toml::Value::Table(t) => {
208            let map = t
209                .into_iter()
210                .map(|(k, v)| (k, value_to_our_value(v)))
211                .collect();
212            Value::Object(map)
213        }
214        toml::Value::Datetime(dt) => Value::String(dt.to_string()),
215    }
216}
217
218fn our_value_to_toml_value(v: &Value) -> DocumentResult<toml::Value> {
219    match v {
220        Value::Null => Err(DocumentError::UnsupportedOperation {
221            format: "TOML".to_string(),
222            operation: "save".to_string(),
223            detail: "TOML has no null value".to_string(),
224        }),
225        Value::Bool(b) => Ok(toml::Value::Boolean(*b)),
226        Value::Integer(i) => Ok(toml::Value::Integer(*i)),
227        Value::Unsigned(i) => i64::try_from(*i).map(toml::Value::Integer).map_err(|_| {
228            DocumentError::UnsupportedOperation {
229                format: "TOML".to_string(),
230                operation: "save".to_string(),
231                detail: "unsigned integer exceeds TOML i64 range".to_string(),
232            }
233        }),
234        Value::Float(f) => Ok(toml::Value::Float(*f)),
235        Value::Number(text) if v.is_float() => text
236            .parse::<f64>()
237            .ok()
238            .filter(|value| value.is_finite())
239            .map(toml::Value::Float)
240            .ok_or_else(|| DocumentError::UnsupportedOperation {
241                format: "TOML".to_string(),
242                operation: "save".to_string(),
243                detail: format!("float literal `{text}` is not representable in TOML"),
244            }),
245        Value::Number(text) => Err(DocumentError::UnsupportedOperation {
246            format: "TOML".to_string(),
247            operation: "save".to_string(),
248            detail: format!("integer literal `{text}` exceeds TOML's 64-bit integer range"),
249        }),
250        Value::String(s) => Ok(toml::Value::String(s.clone())),
251        Value::Array(a) => {
252            let arr = a
253                .iter()
254                .map(our_value_to_toml_value)
255                .collect::<DocumentResult<Vec<_>>>()?;
256            Ok(toml::Value::Array(arr))
257        }
258        Value::Object(o) => {
259            let mut table = toml::map::Map::new();
260            for (k, v) in o {
261                table.insert(k.clone(), our_value_to_toml_value(v)?);
262            }
263            Ok(toml::Value::Table(table))
264        }
265    }
266}
agent_first_data/document/format/toml.rs

agent_first_data/document/format/
toml.rs
