Split formatting functionality into two files

This commit is contained in:
Patrick Lühne 2020-03-30 04:27:58 +02:00
parent caf957deed
commit a3da369346
Signed by: patrick
GPG Key ID: 05F3611E97A70ABF
3 changed files with 526 additions and 518 deletions

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@ -1,522 +1,9 @@
mod formulas;
mod terms;
pub(crate) use terms::*;
trait Precedence
{
fn precedence(&self) -> i32;
}
impl Precedence for crate::Term
{
fn precedence(&self) -> i32
{
match &self
{
Self::Boolean(_)
| Self::Function(_)
| Self::SpecialInteger(_)
| Self::Integer(_)
| Self::String(_)
| Self::Variable(_)
| Self::UnaryOperation(
crate::UnaryOperation{operator: crate::UnaryOperator::AbsoluteValue, ..})
=> 0,
Self::UnaryOperation(
crate::UnaryOperation{operator: crate::UnaryOperator::Negative, ..})
=> 1,
Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Exponentiate, ..})
=> 2,
Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Multiply, ..})
| Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Divide, ..})
| Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Modulo, ..})
=> 3,
Self::BinaryOperation(crate::BinaryOperation{operator: crate::BinaryOperator::Add, ..})
| Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Subtract, ..})
=> 4,
}
}
}
impl Precedence for crate::Formula
{
fn precedence(&self) -> i32
{
match &self
{
Self::Predicate(_)
| Self::Boolean(_)
| Self::Compare(_)
=> 0,
Self::Exists(_)
| Self::ForAll(_)
=> 1,
Self::Not(_)
=> 2,
Self::And(_)
=> 3,
Self::Or(_)
=> 4,
Self::Implies(_)
=> 5,
Self::IfAndOnlyIf(_)
=> 6,
}
}
}
impl std::fmt::Debug for crate::ImplicationDirection
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
match &self
{
crate::ImplicationDirection::LeftToRight => write!(format, "left to right"),
crate::ImplicationDirection::RightToLeft => write!(format, "right to left"),
}
}
}
impl std::fmt::Debug for crate::SpecialInteger
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
match &self
{
Self::Infimum => write!(format, "#inf"),
Self::Supremum => write!(format, "#sup"),
}
}
}
impl std::fmt::Display for crate::SpecialInteger
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", &self)
}
}
impl std::fmt::Debug for crate::FunctionDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}/{}", &self.name, self.arity)
}
}
impl std::fmt::Display for crate::FunctionDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", &self)
}
}
impl std::fmt::Debug for crate::PredicateDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}/{}", &self.name, self.arity)
}
}
impl std::fmt::Display for crate::PredicateDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", &self)
}
}
impl std::fmt::Debug for crate::VariableDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}", &self.name)
}
}
impl std::fmt::Display for crate::VariableDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", &self)
}
}
struct TermDisplay<'term>
{
parent_precedence: Option<i32>,
term: &'term crate::Term,
}
fn display_term(term: &crate::Term, parent_precedence: Option<i32>) -> TermDisplay
{
TermDisplay
{
parent_precedence,
term,
}
}
impl<'term> std::fmt::Debug for TermDisplay<'term>
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
let precedence = self.term.precedence();
let requires_parentheses = match self.parent_precedence
{
Some(parent_precedence) => precedence > parent_precedence,
None => false,
};
if requires_parentheses
{
write!(format, "(")?;
}
match &self.term
{
crate::Term::Boolean(true) => write!(format, "true"),
crate::Term::Boolean(false) => write!(format, "false"),
crate::Term::SpecialInteger(value) => write!(format, "{:?}", value),
crate::Term::Integer(value) => write!(format, "{}", value),
crate::Term::String(value) => write!(format, "\"{}\"", value),
crate::Term::Variable(variable) => write!(format, "{:?}", variable.declaration),
crate::Term::Function(function) =>
{
write!(format, "{}", function.declaration.name)?;
assert!(function.declaration.arity == function.arguments.len(),
"number of function arguments differs from declaration (expected {}, got {})",
function.declaration.arity, function.arguments.len());
if !function.arguments.is_empty()
{
write!(format, "(")?;
let mut separator = "";
for argument in &function.arguments
{
write!(format, "{}{:?}", separator, display_term(&argument, None))?;
separator = ", ";
}
write!(format, ")")?;
}
Ok(())
},
crate::Term::BinaryOperation(binary_operation) =>
{
let operator_string = match binary_operation.operator
{
crate::BinaryOperator::Add => "+",
crate::BinaryOperator::Subtract => "-",
crate::BinaryOperator::Multiply => "*",
crate::BinaryOperator::Divide => "/",
crate::BinaryOperator::Modulo => "%",
crate::BinaryOperator::Exponentiate => "**",
};
let left_requires_parentheses = binary_operation.left.precedence() == precedence
// Exponentiation is right-associative and thus requires parentheses when
// nested on the left side
&& binary_operation.operator == crate::BinaryOperator::Exponentiate;
// The subtraction, division, and modulo operators require parentheses around the
// right argument even if it has the same precedence
let operator_requires_right_priority = match binary_operation.operator
{
crate::BinaryOperator::Subtract
| crate::BinaryOperator::Divide
| crate::BinaryOperator::Modulo
=> true,
_ => false,
};
// Additionally, modulo operations nested to the right of another multiplicative
// operation always require parentheses
let right_requires_priority = match *binary_operation.right
{
crate::Term::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Modulo, ..})
=> true,
_ => false,
};
let right_requires_parentheses = binary_operation.right.precedence() == precedence
&& (operator_requires_right_priority || right_requires_priority);
if left_requires_parentheses
{
write!(format, "(")?;
}
write!(format, "{:?}", display_term(&binary_operation.left, Some(precedence)))?;
if left_requires_parentheses
{
write!(format, ")")?;
}
write!(format, " {} ", operator_string)?;
if right_requires_parentheses
{
write!(format, "(")?;
}
write!(format, "{:?}", display_term(&binary_operation.right, Some(precedence)))?;
if right_requires_parentheses
{
write!(format, ")")?;
}
Ok(())
},
crate::Term::UnaryOperation(
crate::UnaryOperation{operator: crate::UnaryOperator::Negative, argument})
=> write!(format, "-{:?}", display_term(argument, Some(precedence))),
crate::Term::UnaryOperation(
crate::UnaryOperation{operator: crate::UnaryOperator::AbsoluteValue, argument})
=> write!(format, "|{:?}|", display_term(argument, None)),
}?;
if requires_parentheses
{
write!(format, ")")?;
}
Ok(())
}
}
impl<'term> std::fmt::Display for TermDisplay<'term>
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", self)
}
}
struct FormulaDisplay<'formula>
{
parent_precedence: Option<i32>,
formula: &'formula crate::Formula,
}
fn display_formula(formula: &crate::Formula, parent_precedence: Option<i32>) -> FormulaDisplay
{
FormulaDisplay
{
parent_precedence,
formula,
}
}
impl<'formula> std::fmt::Debug for FormulaDisplay<'formula>
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
let precedence = self.formula.precedence();
let requires_parentheses = match self.parent_precedence
{
Some(parent_precedence) => precedence > parent_precedence,
None => false,
};
let precedence = Some(precedence);
if requires_parentheses
{
write!(format, "(")?;
}
match &self.formula
{
crate::Formula::Exists(exists) =>
{
assert!(!exists.parameters.is_empty());
write!(format, "exists")?;
let mut separator = " ";
for parameter in exists.parameters.iter()
{
write!(format, "{}{:?}", separator, parameter)?;
separator = ", "
}
write!(format, " {:?}", display_formula(&exists.argument, precedence))?;
},
crate::Formula::ForAll(for_all) =>
{
assert!(!for_all.parameters.is_empty());
write!(format, "forall")?;
let mut separator = " ";
for parameter in for_all.parameters.iter()
{
write!(format, "{}{:?}", separator, parameter)?;
separator = ", "
}
write!(format, " {:?}", display_formula(&for_all.argument, precedence))?;
},
crate::Formula::Not(argument) => write!(format, "not {:?}",
display_formula(argument, precedence))?,
crate::Formula::And(arguments) =>
{
let mut separator = "";
assert!(!arguments.is_empty());
for argument in arguments
{
write!(format, "{}{:?}", separator, display_formula(argument, precedence))?;
separator = " and "
}
},
crate::Formula::Or(arguments) =>
{
let mut separator = "";
assert!(!arguments.is_empty());
for argument in arguments
{
write!(format, "{}{:?}", separator, display_formula(argument, precedence))?;
separator = " or "
}
},
crate::Formula::Implies(crate::Implies{direction, antecedent, implication}) =>
{
match direction
{
crate::ImplicationDirection::LeftToRight =>
write!(format, "{:?} -> {:?}", display_formula(antecedent, precedence),
display_formula(implication, precedence))?,
crate::ImplicationDirection::RightToLeft =>
write!(format, "{:?} <- {:?}", display_formula(implication, precedence),
display_formula(antecedent, precedence))?,
};
},
crate::Formula::IfAndOnlyIf(arguments) =>
{
let mut separator = "";
for argument in arguments
{
write!(format, "{}{:?}", separator, display_formula(argument, precedence))?;
separator = " <-> ";
}
},
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::Less, left, right})
=> write!(format, "{:?} < {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::LessOrEqual, left, right})
=> write!(format, "{:?} <= {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::Greater, left, right})
=> write!(format, "{:?} > {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::GreaterOrEqual, left, right})
=> write!(format, "{:?} >= {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::Equal, left, right})
=> write!(format, "{:?} = {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::NotEqual, left, right})
=> write!(format, "{:?} != {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Boolean(true) => write!(format, "true")?,
crate::Formula::Boolean(false) => write!(format, "false")?,
crate::Formula::Predicate(predicate) =>
{
write!(format, "{}", predicate.declaration.name)?;
if !predicate.arguments.is_empty()
{
write!(format, "(")?;
let mut separator = "";
for argument in &predicate.arguments
{
write!(format, "{}{:?}", separator, display_term(argument, None))?;
separator = ", "
}
write!(format, ")")?;
}
},
}
if requires_parentheses
{
write!(format, ")")?;
}
Ok(())
}
}
impl<'formula> std::fmt::Display for FormulaDisplay<'formula>
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", self)
}
}
impl std::fmt::Debug for crate::Formula
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", display_formula(&self, None))
}
}
impl std::fmt::Display for crate::Formula
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}", display_formula(&self, None))
}
}
impl std::fmt::Debug for crate::Term
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", display_term(&self, None))
}
}
impl std::fmt::Display for crate::Term
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}", display_term(&self, None))
}
}

256
src/format/formulas.rs Normal file
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@ -0,0 +1,256 @@
use super::*;
impl super::Precedence for crate::Formula
{
fn precedence(&self) -> i32
{
match &self
{
Self::Predicate(_)
| Self::Boolean(_)
| Self::Compare(_)
=> 0,
Self::Exists(_)
| Self::ForAll(_)
=> 1,
Self::Not(_)
=> 2,
Self::And(_)
=> 3,
Self::Or(_)
=> 4,
Self::Implies(_)
=> 5,
Self::IfAndOnlyIf(_)
=> 6,
}
}
}
impl std::fmt::Debug for crate::ImplicationDirection
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
match &self
{
Self::LeftToRight => write!(format, "left to right"),
Self::RightToLeft => write!(format, "right to left"),
}
}
}
impl std::fmt::Debug for crate::PredicateDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}/{}", &self.name, self.arity)
}
}
impl std::fmt::Display for crate::PredicateDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", &self)
}
}
struct FormulaDisplay<'formula>
{
parent_precedence: Option<i32>,
formula: &'formula crate::Formula,
}
fn display_formula(formula: &crate::Formula, parent_precedence: Option<i32>) -> FormulaDisplay
{
FormulaDisplay
{
parent_precedence,
formula,
}
}
impl<'formula> std::fmt::Debug for FormulaDisplay<'formula>
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
let precedence = self.formula.precedence();
let requires_parentheses = match self.parent_precedence
{
Some(parent_precedence) => precedence > parent_precedence,
None => false,
};
let precedence = Some(precedence);
if requires_parentheses
{
write!(format, "(")?;
}
match &self.formula
{
crate::Formula::Exists(exists) =>
{
assert!(!exists.parameters.is_empty());
write!(format, "exists")?;
let mut separator = " ";
for parameter in exists.parameters.iter()
{
write!(format, "{}{:?}", separator, parameter)?;
separator = ", "
}
write!(format, " {:?}", display_formula(&exists.argument, precedence))?;
},
crate::Formula::ForAll(for_all) =>
{
assert!(!for_all.parameters.is_empty());
write!(format, "forall")?;
let mut separator = " ";
for parameter in for_all.parameters.iter()
{
write!(format, "{}{:?}", separator, parameter)?;
separator = ", "
}
write!(format, " {:?}", display_formula(&for_all.argument, precedence))?;
},
crate::Formula::Not(argument) => write!(format, "not {:?}",
display_formula(argument, precedence))?,
crate::Formula::And(arguments) =>
{
let mut separator = "";
assert!(!arguments.is_empty());
for argument in arguments
{
write!(format, "{}{:?}", separator, display_formula(argument, precedence))?;
separator = " and "
}
},
crate::Formula::Or(arguments) =>
{
let mut separator = "";
assert!(!arguments.is_empty());
for argument in arguments
{
write!(format, "{}{:?}", separator, display_formula(argument, precedence))?;
separator = " or "
}
},
crate::Formula::Implies(crate::Implies{direction, antecedent, implication}) =>
{
match direction
{
crate::ImplicationDirection::LeftToRight =>
write!(format, "{:?} -> {:?}", display_formula(antecedent, precedence),
display_formula(implication, precedence))?,
crate::ImplicationDirection::RightToLeft =>
write!(format, "{:?} <- {:?}", display_formula(implication, precedence),
display_formula(antecedent, precedence))?,
};
},
crate::Formula::IfAndOnlyIf(arguments) =>
{
let mut separator = "";
for argument in arguments
{
write!(format, "{}{:?}", separator, display_formula(argument, precedence))?;
separator = " <-> ";
}
},
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::Less, left, right})
=> write!(format, "{:?} < {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::LessOrEqual, left, right})
=> write!(format, "{:?} <= {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::Greater, left, right})
=> write!(format, "{:?} > {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::GreaterOrEqual, left, right})
=> write!(format, "{:?} >= {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::Equal, left, right})
=> write!(format, "{:?} = {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Compare(
crate::Compare{operator: crate::ComparisonOperator::NotEqual, left, right})
=> write!(format, "{:?} != {:?}", display_term(left, None),
display_term(right, None))?,
crate::Formula::Boolean(true) => write!(format, "true")?,
crate::Formula::Boolean(false) => write!(format, "false")?,
crate::Formula::Predicate(predicate) =>
{
write!(format, "{}", predicate.declaration.name)?;
if !predicate.arguments.is_empty()
{
write!(format, "(")?;
let mut separator = "";
for argument in &predicate.arguments
{
write!(format, "{}{:?}", separator, display_term(argument, None))?;
separator = ", "
}
write!(format, ")")?;
}
},
}
if requires_parentheses
{
write!(format, ")")?;
}
Ok(())
}
}
impl<'formula> std::fmt::Display for FormulaDisplay<'formula>
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", self)
}
}
impl std::fmt::Debug for crate::Formula
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", display_formula(&self, None))
}
}
impl std::fmt::Display for crate::Formula
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}", display_formula(&self, None))
}
}

265
src/format/terms.rs Normal file
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@ -0,0 +1,265 @@
use super::*;
impl super::Precedence for crate::Term
{
fn precedence(&self) -> i32
{
match &self
{
Self::Boolean(_)
| Self::SpecialInteger(_)
| Self::Integer(_)
| Self::String(_)
| Self::Variable(_)
| Self::Function(_)
| Self::UnaryOperation(
crate::UnaryOperation{operator: crate::UnaryOperator::AbsoluteValue, ..})
=> 0,
Self::UnaryOperation(
crate::UnaryOperation{operator: crate::UnaryOperator::Negative, ..})
=> 1,
Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Exponentiate, ..})
=> 2,
Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Multiply, ..})
| Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Divide, ..})
| Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Modulo, ..})
=> 3,
Self::BinaryOperation(crate::BinaryOperation{operator: crate::BinaryOperator::Add, ..})
| Self::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Subtract, ..})
=> 4,
}
}
}
impl std::fmt::Debug for crate::SpecialInteger
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
match &self
{
Self::Infimum => write!(format, "#inf"),
Self::Supremum => write!(format, "#sup"),
}
}
}
impl std::fmt::Display for crate::SpecialInteger
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", &self)
}
}
impl std::fmt::Debug for crate::FunctionDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}/{}", &self.name, self.arity)
}
}
impl std::fmt::Display for crate::FunctionDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", &self)
}
}
impl std::fmt::Debug for crate::VariableDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}", &self.name)
}
}
impl std::fmt::Display for crate::VariableDeclaration
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", &self)
}
}
pub(crate) struct TermDisplay<'term>
{
parent_precedence: Option<i32>,
term: &'term crate::Term,
}
pub(crate) fn display_term(term: &crate::Term, parent_precedence: Option<i32>) -> TermDisplay
{
TermDisplay
{
parent_precedence,
term,
}
}
impl<'term> std::fmt::Debug for TermDisplay<'term>
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
let precedence = self.term.precedence();
let requires_parentheses = match self.parent_precedence
{
Some(parent_precedence) => precedence > parent_precedence,
None => false,
};
if requires_parentheses
{
write!(format, "(")?;
}
match &self.term
{
crate::Term::Boolean(true) => write!(format, "true"),
crate::Term::Boolean(false) => write!(format, "false"),
crate::Term::SpecialInteger(value) => write!(format, "{:?}", value),
crate::Term::Integer(value) => write!(format, "{}", value),
crate::Term::String(value) => write!(format, "\"{}\"",
value.replace("\\", "\\\\").replace("\n", "\\n").replace("\t", "\\t")),
crate::Term::Variable(variable) => write!(format, "{:?}", variable.declaration),
crate::Term::Function(function) =>
{
write!(format, "{}", function.declaration.name)?;
assert!(function.declaration.arity == function.arguments.len(),
"number of function arguments differs from declaration (expected {}, got {})",
function.declaration.arity, function.arguments.len());
if !function.arguments.is_empty()
{
write!(format, "(")?;
let mut separator = "";
for argument in &function.arguments
{
write!(format, "{}{:?}", separator, display_term(&argument, None))?;
separator = ", ";
}
write!(format, ")")?;
}
Ok(())
},
crate::Term::BinaryOperation(binary_operation) =>
{
let operator_string = match binary_operation.operator
{
crate::BinaryOperator::Add => "+",
crate::BinaryOperator::Subtract => "-",
crate::BinaryOperator::Multiply => "*",
crate::BinaryOperator::Divide => "/",
crate::BinaryOperator::Modulo => "%",
crate::BinaryOperator::Exponentiate => "**",
};
let left_requires_parentheses = binary_operation.left.precedence() == precedence
// Exponentiation is right-associative and thus requires parentheses when
// nested on the left side
&& binary_operation.operator == crate::BinaryOperator::Exponentiate;
// The subtraction, division, and modulo operators require parentheses around the
// right argument even if it has the same precedence
let operator_requires_right_priority = match binary_operation.operator
{
crate::BinaryOperator::Subtract
| crate::BinaryOperator::Divide
| crate::BinaryOperator::Modulo
=> true,
_ => false,
};
// Additionally, modulo operations nested to the right of another multiplicative
// operation always require parentheses
let right_requires_priority = match *binary_operation.right
{
crate::Term::BinaryOperation(
crate::BinaryOperation{operator: crate::BinaryOperator::Modulo, ..})
=> true,
_ => false,
};
let right_requires_parentheses = binary_operation.right.precedence() == precedence
&& (operator_requires_right_priority || right_requires_priority);
if left_requires_parentheses
{
write!(format, "(")?;
}
write!(format, "{:?}", display_term(&binary_operation.left, Some(precedence)))?;
if left_requires_parentheses
{
write!(format, ")")?;
}
write!(format, " {} ", operator_string)?;
if right_requires_parentheses
{
write!(format, "(")?;
}
write!(format, "{:?}", display_term(&binary_operation.right, Some(precedence)))?;
if right_requires_parentheses
{
write!(format, ")")?;
}
Ok(())
},
crate::Term::UnaryOperation(
crate::UnaryOperation{operator: crate::UnaryOperator::Negative, argument})
=> write!(format, "-{:?}", display_term(argument, Some(precedence))),
crate::Term::UnaryOperation(
crate::UnaryOperation{operator: crate::UnaryOperator::AbsoluteValue, argument})
=> write!(format, "|{:?}|", display_term(argument, None)),
}?;
if requires_parentheses
{
write!(format, ")")?;
}
Ok(())
}
}
impl<'term> std::fmt::Display for TermDisplay<'term>
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", self)
}
}
impl std::fmt::Debug for crate::Term
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{:?}", display_term(&self, None))
}
}
impl std::fmt::Display for crate::Term
{
fn fmt(&self, format: &mut std::fmt::Formatter) -> std::fmt::Result
{
write!(format, "{}", display_term(&self, None))
}
}