skillet 0.6.0

Skillet: micro expression language (arithmetic, logical, functions, arrays, conditionals, excel formulas) made in Rust bin cli and server
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
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217

pub mod ast;
pub mod concurrent_registry;
pub mod custom;
pub mod error;
#[cfg(feature = "plugins")]
pub mod js_plugin;
pub mod lexer;
pub mod memory_pool;
pub mod parser;
pub mod runtime;
pub mod traits;
pub mod types;

pub use ast::Expr;
pub use custom::{CustomFunction, FunctionRegistry};
pub use error::Error;
#[cfg(feature = "plugins")]
pub use js_plugin::{JavaScriptFunction, JSPluginLoader};
pub use types::Value;
use std::collections::HashMap;
use std::sync::{Arc, RwLock};

/// Sanitize JSON keys by replacing special characters with underscores
fn sanitize_json_key(key: &str) -> String {
    key.chars()
        .map(|c| {
            if c.is_alphanumeric() || c == '_' {
                c
            } else {
                '_'
            }
        })
        .collect()
}

// Global function registry
lazy_static::lazy_static! {
    static ref GLOBAL_REGISTRY: Arc<RwLock<FunctionRegistry>> = Arc::new(RwLock::new(FunctionRegistry::new()));
}

/// Parse an arithmetic expression (optional leading '=') into an AST.
pub fn parse(input: &str) -> Result<Expr, Error> {
    // Allow optional leading '=' after whitespace
    let trimmed = input.trim_start();
    let input2: std::borrow::Cow<'_, str> = if let Some(rest) = trimmed.strip_prefix('=') { std::borrow::Cow::from(rest) } else { std::borrow::Cow::from(input) };
    let mut parser = parser::Parser::new(&input2);
    parser.parse()
}

/// Evaluate an arithmetic expression to f64.
pub fn evaluate(input: &str) -> Result<Value, Error> {
    let expr = parse(input)?;
    runtime::evaluator::eval(&expr)
}

/// Evaluate with a map of numeric variables and built-in functions.
pub fn evaluate_with(input: &str, vars: &HashMap<String, Value>) -> Result<Value, Error> {
    let expr = parse(input)?;
    runtime::evaluator::eval_with_vars(&expr, vars)
}

/// Evaluate with variables provided as JSON string.
/// JSON format: {"var1": "value1", "var2": 42, "var3": true}
/// Supports flat JSON structure with automatic type conversion.
/// JSON keys with special characters are sanitized to valid variable names.
pub fn evaluate_with_json(input: &str, json_vars: &str) -> Result<Value, Error> {
    let json_value: serde_json::Value = serde_json::from_str(json_vars)
        .map_err(|e| Error::new(format!("Invalid JSON: {}", e), None))?;

    let vars = match json_value {
        serde_json::Value::Object(map) => {
            let mut result = HashMap::new();

            // Add the original JSON data for JQ function
            result.insert("arguments".to_string(), Value::Json(json_vars.to_string()));

            for (key, value) in map {
                let skillet_value = json_to_value(value)?;
                let sanitized_key = sanitize_json_key(&key);
                result.insert(sanitized_key, skillet_value);
            }
            result
        }
        _ => return Err(Error::new("JSON must be an object with key-value pairs", None)),
    };

    evaluate_with(input, &vars)
}

/// Convert serde_json::Value to skillet::Value with type inference
pub fn json_to_value(json: serde_json::Value) -> Result<Value, Error> {
    match json {
        serde_json::Value::Null => Ok(Value::Null),
        serde_json::Value::Bool(b) => Ok(Value::Boolean(b)),
        serde_json::Value::Number(n) => {
            if let Some(i) = n.as_i64() {
                Ok(Value::Number(i as f64))
            } else if let Some(f) = n.as_f64() {
                Ok(Value::Number(f))
            } else {
                Err(Error::new("Invalid number in JSON", None))
            }
        }
        serde_json::Value::String(s) => Ok(Value::String(s)),
        serde_json::Value::Array(arr) => {
            let mut result = Vec::new();
            for item in arr {
                result.push(json_to_value(item)?);
            }
            Ok(Value::Array(result))
        }
        serde_json::Value::Object(_) => {
            // For nested objects, convert to JSON string
            let json_str = serde_json::to_string(&json)
                .map_err(|e| Error::new(format!("Failed to serialize JSON object: {}", e), None))?;
            Ok(Value::Json(json_str))
        }
    }
}

/// Register a custom function globally
pub fn register_function(function: Box<dyn CustomFunction>) -> Result<(), Error> {
    let mut registry = GLOBAL_REGISTRY.write()
        .map_err(|_| Error::new("Failed to acquire registry lock", None))?;
    registry.register(function)
}

/// Unregister a custom function by name
pub fn unregister_function(name: &str) -> bool {
    if let Ok(mut registry) = GLOBAL_REGISTRY.write() {
        registry.unregister(name)
    } else {
        false
    }
}

/// List all registered custom functions
pub fn list_custom_functions() -> Vec<String> {
    if let Ok(registry) = GLOBAL_REGISTRY.read() {
        registry.list_functions().iter().map(|s| s.to_string()).collect()
    } else {
        Vec::new()
    }
}

/// Check if a custom function is registered
pub fn has_custom_function(name: &str) -> bool {
    if let Ok(registry) = GLOBAL_REGISTRY.read() {
        registry.has_function(name)
    } else {
        false
    }
}

/// Evaluate with custom functions support
pub fn evaluate_with_custom(input: &str, vars: &HashMap<String, Value>) -> Result<Value, Error> {
    let expr = parse(input)?;
    runtime::evaluator::eval_with_vars_and_custom(&expr, vars, &GLOBAL_REGISTRY)
}

/// Evaluate with JSON and custom functions support
/// JSON keys with special characters are sanitized to valid variable names.
pub fn evaluate_with_json_custom(input: &str, json_vars: &str) -> Result<Value, Error> {
    let json_value: serde_json::Value = serde_json::from_str(json_vars)
        .map_err(|e| Error::new(format!("Invalid JSON: {}", e), None))?;

    let vars = match json_value {
        serde_json::Value::Object(map) => {
            let mut result = HashMap::new();

            // Add the original JSON data for JQ function
            result.insert("arguments".to_string(), Value::Json(json_vars.to_string()));

            for (key, value) in map {
                let skillet_value = json_to_value(value)?;
                let sanitized_key = sanitize_json_key(&key);
                result.insert(sanitized_key, skillet_value);
            }
            result
        }
        _ => return Err(Error::new("JSON must be an object with key-value pairs", None)),
    };

    evaluate_with_custom(input, &vars)
}


/// Evaluate with assignments and sequences - handles complex expressions with variable assignments
pub fn evaluate_with_assignments(input: &str, vars: &HashMap<String, Value>) -> Result<Value, Error> {
    let expr = parse(input)?;
    runtime::evaluator::eval_with_assignments(&expr, vars)
}

/// Evaluate with assignments and sequences, returning both result and variable context
pub fn evaluate_with_assignments_and_context(input: &str, vars: &HashMap<String, Value>) -> Result<(Value, HashMap<String, Value>), Error> {
    let expr = parse(input)?;
    runtime::evaluator::eval_with_assignments_and_context(&expr, vars)
}

#[cfg(test)]
mod tests {
    use super::*;

    fn approxv(v: Value, b: f64) -> bool { matches!(v, Value::Number(a) if (a - b).abs() < 1e-9) }

    #[test]
    fn test_basic_arithmetic() {
        assert!(approxv(evaluate("2 + 3 * 4").unwrap(), 14.0));
        assert!(approxv(evaluate("(2 + 3) * 4").unwrap(), 20.0));
        assert!(approxv(evaluate("2 ^ 3").unwrap(), 8.0));
        assert!(approxv(evaluate("2 ^ 3 ^ 2").unwrap(), 512.0));
        assert!(approxv(evaluate("-3 ^ 2").unwrap(), -9.0));
        assert!(approxv(evaluate("(-3) ^ 2").unwrap(), 9.0));
        assert!(approxv(evaluate("= 10 + 20 * 3").unwrap(), 70.0));
        assert!(approxv(evaluate("= (10 + 20) * 3").unwrap(), 90.0));
    }
}