use thiserror::Error;
#[derive(Debug, Error, Clone, PartialEq)]
pub enum LocyCompileError {
#[error("cyclic negation among rules: {}", rules.join(", "))]
CyclicNegation { rules: Vec<String> },
#[error("undefined rule: {name}")]
UndefinedRule { name: String },
#[error("prev reference in non-recursive rule '{rule}', field '{field}'")]
PrevInBaseCase { rule: String, field: String },
#[error("non-monotonic aggregate '{aggregate}' in recursive rule '{rule}'")]
NonMonotonicInRecursion { rule: String, aggregate: String },
#[error("BEST BY with monotonic fold '{fold}' in rule '{rule}'")]
BestByWithMonotonicFold { rule: String, fold: String },
#[error("post-FOLD WHERE in rule '{rule}' requires a FOLD clause")]
HavingWithoutFold { rule: String },
#[error("wardedness violation: variable '{variable}' in rule '{rule}' not bound by MATCH")]
WardednessViolation { rule: String, variable: String },
#[error("YIELD schema mismatch in rule '{rule}': {detail}")]
YieldSchemaMismatch { rule: String, detail: String },
#[error("mixed priority in rule '{rule}': some clauses have PRIORITY, others don't")]
MixedPriority { rule: String },
#[error("module not found: {name}")]
ModuleNotFound { name: String },
#[error("import not found: rule '{rule}' in module '{module}'")]
ImportNotFound { module: String, rule: String },
#[error(
"IS arity mismatch in rule '{rule}': reference to '{target}' provides {actual} bindings, but '{target}' yields {expected} columns"
)]
IsArityMismatch {
rule: String,
target: String,
expected: usize,
actual: usize,
},
#[error(
"prev.{field} in rule '{rule}' references unknown column; available columns from IS references: {available}"
)]
PrevFieldNotInSchema {
rule: String,
field: String,
available: String,
},
#[error("rule '{rule}' has {count} PROB columns; at most 1 is allowed")]
MultipleProbColumns { rule: String, count: usize },
}