443 lines
11 KiB
Rust
443 lines
11 KiB
Rust
use super::tokens::*;
|
|
|
|
pub fn parse_term(input: &str) -> Result<crate::Term, crate::parse::Error>
|
|
{
|
|
let term_str = TermStr::new(input);
|
|
term_str.parse(0)?;
|
|
|
|
// TODO: implement correctly
|
|
Ok(crate::Term::true_())
|
|
}
|
|
|
|
pub(crate) fn function_name(input: &str) -> Option<(&str, &str)>
|
|
{
|
|
let (identifier, remaining_input) = identifier(input)?;
|
|
|
|
if is_keyword(identifier)
|
|
{
|
|
return None;
|
|
}
|
|
|
|
let mut characters = identifier.chars();
|
|
|
|
while let Some(character) = characters.next()
|
|
{
|
|
match character
|
|
{
|
|
'_' => continue,
|
|
_ if character.is_ascii_lowercase() => return Some((identifier, remaining_input)),
|
|
_ => return None,
|
|
}
|
|
}
|
|
|
|
None
|
|
}
|
|
|
|
fn variable_name(input: &str) -> Option<(&str, &str)>
|
|
{
|
|
let (identifier, remaining_input) = identifier(input)?;
|
|
|
|
let mut characters = identifier.chars();
|
|
|
|
while let Some(character) = characters.next()
|
|
{
|
|
match character
|
|
{
|
|
'_' => continue,
|
|
_ if character.is_ascii_uppercase() => return Some((identifier, remaining_input)),
|
|
_ => return None,
|
|
}
|
|
}
|
|
|
|
None
|
|
}
|
|
|
|
pub(crate) fn variable_declaration(input: &str) -> Option<(crate::VariableDeclaration, &str)>
|
|
{
|
|
variable_name(input)
|
|
.map(|(variable_name, remaining_input)|
|
|
(crate::VariableDeclaration::new(variable_name.to_string()), remaining_input))
|
|
}
|
|
|
|
pub(crate) fn variable_declarations(input: &str)
|
|
-> Result<Option<(crate::VariableDeclarations, &str)>, crate::parse::Error>
|
|
{
|
|
let mut variable_declarations = vec![];
|
|
|
|
let (first_variable_declaration, mut input) = match variable_declaration(input)
|
|
{
|
|
Some(first_variable_declaration) => first_variable_declaration,
|
|
None => return Ok(None),
|
|
};
|
|
|
|
variable_declarations.push(std::rc::Rc::new(first_variable_declaration));
|
|
|
|
loop
|
|
{
|
|
input = input.trim_start();
|
|
|
|
input = match symbol(input)
|
|
{
|
|
Some((Symbol::Comma, input)) => input,
|
|
// TODO: detect redeclarations, such as in “exists X, Y, X”
|
|
_ => return Ok(Some((variable_declarations, input))),
|
|
};
|
|
|
|
input = input.trim_start();
|
|
|
|
let (variable_declaration, remaining_input) = match variable_declaration(input)
|
|
{
|
|
Some(variable_declaration) => variable_declaration,
|
|
None => return Err(crate::parse::Error::new_expected_variable_declaration(
|
|
crate::parse::error::Location::new(0, Some(0)))),
|
|
};
|
|
|
|
input = remaining_input;
|
|
|
|
variable_declarations.push(std::rc::Rc::new(variable_declaration));
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, Copy, Eq, PartialEq)]
|
|
pub(crate) enum TermInfixOperator
|
|
{
|
|
Add,
|
|
Divide,
|
|
Exponentiate,
|
|
Modulo,
|
|
Multiply,
|
|
Subtract,
|
|
}
|
|
|
|
impl TermInfixOperator
|
|
{
|
|
fn level(&self) -> usize
|
|
{
|
|
match self
|
|
{
|
|
Self::Exponentiate => 1,
|
|
Self::Multiply
|
|
| Self::Divide
|
|
| Self::Modulo => 2,
|
|
Self::Add
|
|
| Self::Subtract => 3,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl std::fmt::Debug for TermInfixOperator
|
|
{
|
|
fn fmt(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result
|
|
{
|
|
match &self
|
|
{
|
|
Self::Add => write!(formatter, "+"),
|
|
Self::Divide => write!(formatter, "/"),
|
|
Self::Exponentiate => write!(formatter, "**"),
|
|
// TODO: conflicts with single-line comments
|
|
Self::Modulo => write!(formatter, "%"),
|
|
Self::Multiply => write!(formatter, "*"),
|
|
Self::Subtract => write!(formatter, "-"),
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(crate) struct TermStr<'i>
|
|
{
|
|
input: &'i str,
|
|
}
|
|
|
|
impl<'i> TermStr<'i>
|
|
{
|
|
pub fn new(input: &'i str) -> Self
|
|
{
|
|
Self
|
|
{
|
|
input,
|
|
}
|
|
}
|
|
|
|
pub fn iter_infix_operators(&self) -> TermInfixOperatorIterator<'i>
|
|
{
|
|
TermInfixOperatorIterator::new(self.input)
|
|
}
|
|
|
|
pub fn split_at_infix_operator(&self, infix_operator: TermInfixOperator)
|
|
-> SplitTermAtInfixOperator<'i>
|
|
{
|
|
SplitTermAtInfixOperator::new(self, infix_operator)
|
|
}
|
|
|
|
pub fn parse(&self, level: usize) -> Result<crate::Term, crate::parse::Error>
|
|
{
|
|
let indentation = " ".repeat(level);
|
|
println!("{}- parsing term: {}", indentation, self.input);
|
|
|
|
let input = self.input.trim_start();
|
|
|
|
// TODO: implement
|
|
Ok(crate::Term::true_())
|
|
}
|
|
}
|
|
|
|
pub(crate) struct TermInfixOperatorIterator<'i>
|
|
{
|
|
original_input: &'i str,
|
|
input: &'i str,
|
|
}
|
|
|
|
impl<'i> TermInfixOperatorIterator<'i>
|
|
{
|
|
pub fn new(input: &'i str) -> Self
|
|
{
|
|
Self
|
|
{
|
|
original_input: input,
|
|
input,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'i> std::iter::Iterator for TermInfixOperatorIterator<'i>
|
|
{
|
|
type Item = Result<(&'i str, &'i str, TermInfixOperator), crate::parse::Error>;
|
|
|
|
fn next(&mut self) -> Option<Self::Item>
|
|
{
|
|
loop
|
|
{
|
|
self.input = self.input.trim_start();
|
|
|
|
let first_character = match self.input.chars().next()
|
|
{
|
|
None => return None,
|
|
Some(first_character) => first_character,
|
|
};
|
|
|
|
// TODO: implement
|
|
if self.input.starts_with("|")
|
|
{
|
|
unimplemented!();
|
|
}
|
|
|
|
if self.input.starts_with(")")
|
|
{
|
|
return Some(Err(crate::parse::Error::new_unmatched_parenthesis(
|
|
crate::parse::error::Location::new(0, Some(1)))));
|
|
}
|
|
|
|
match parenthesized_expression(self.input)
|
|
{
|
|
Ok(Some((_, remaining_input))) =>
|
|
{
|
|
self.input = remaining_input;
|
|
continue;
|
|
},
|
|
Ok(None) => (),
|
|
Err(error) => return Some(Err(error)),
|
|
}
|
|
|
|
match number(self.input)
|
|
{
|
|
Ok(Some((_, remaining_input))) =>
|
|
{
|
|
self.input = remaining_input;
|
|
continue;
|
|
}
|
|
Ok(None) => (),
|
|
Err(error) => return Some(Err(error)),
|
|
}
|
|
|
|
let index_left = self.input.as_ptr() as usize - self.original_input.as_ptr() as usize;
|
|
let input_left = self.original_input.split_at(index_left).0.trim_end();
|
|
|
|
if let Some((_, remaining_input)) = identifier(self.input)
|
|
{
|
|
self.input = remaining_input;
|
|
continue;
|
|
}
|
|
|
|
if let Some((symbol, remaining_input)) = symbol(self.input)
|
|
{
|
|
self.input = remaining_input;
|
|
|
|
match symbol
|
|
{
|
|
Symbol::Division => return Some(Ok((input_left, remaining_input,
|
|
TermInfixOperator::Divide))),
|
|
Symbol::Exponentiation => return Some(Ok((input_left, remaining_input,
|
|
TermInfixOperator::Exponentiate))),
|
|
Symbol::Minus => return Some(Ok((input_left, remaining_input,
|
|
TermInfixOperator::Subtract))),
|
|
Symbol::Multiplication => return Some(Ok((input_left, remaining_input,
|
|
TermInfixOperator::Multiply))),
|
|
Symbol::Percent => return Some(Ok((input_left, remaining_input,
|
|
TermInfixOperator::Modulo))),
|
|
Symbol::Plus => return Some(Ok((input_left, remaining_input,
|
|
TermInfixOperator::Add))),
|
|
_ => continue,
|
|
}
|
|
}
|
|
|
|
return Some(Err(crate::parse::Error::new_character_not_allowed(first_character,
|
|
crate::parse::error::Location::new(0, Some(0)))));
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(crate) struct SplitTermAtInfixOperator<'i>
|
|
{
|
|
infix_operator_iterator: TermInfixOperatorIterator<'i>,
|
|
infix_operator: TermInfixOperator,
|
|
previous_index: usize,
|
|
}
|
|
|
|
impl<'i> SplitTermAtInfixOperator<'i>
|
|
{
|
|
pub fn new(input: &TermStr<'i>, infix_operator: TermInfixOperator)
|
|
-> Self
|
|
{
|
|
Self
|
|
{
|
|
infix_operator_iterator: input.iter_infix_operators(),
|
|
infix_operator,
|
|
previous_index: 0,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'i> std::iter::Iterator for SplitTermAtInfixOperator<'i>
|
|
{
|
|
type Item = Result<&'i str, crate::parse::Error>;
|
|
|
|
fn next(&mut self) -> Option<Self::Item>
|
|
{
|
|
loop
|
|
{
|
|
let (input_left, input_right, infix_operator) =
|
|
match self.infix_operator_iterator.next()
|
|
{
|
|
Some(Err(error)) => return Some(Err(error)),
|
|
Some(Ok(infix_operator_iterator_next)) => infix_operator_iterator_next,
|
|
None => break,
|
|
};
|
|
|
|
if infix_operator == self.infix_operator
|
|
{
|
|
// TODO: refactor
|
|
let index = input_left.as_ptr() as usize
|
|
+ input_left.len()
|
|
- self.infix_operator_iterator.original_input.as_ptr() as usize;
|
|
let split_input = &self.infix_operator_iterator
|
|
.original_input[self.previous_index..index].trim();
|
|
self.previous_index = input_right.as_ptr() as usize
|
|
- self.infix_operator_iterator.original_input.as_ptr() as usize;
|
|
|
|
return Some(Ok(split_input));
|
|
}
|
|
}
|
|
|
|
let remaining_input = self.infix_operator_iterator
|
|
.original_input[self.previous_index..].trim();
|
|
|
|
if remaining_input.is_empty()
|
|
{
|
|
None
|
|
}
|
|
else
|
|
{
|
|
self.previous_index = self.infix_operator_iterator.original_input.len();
|
|
|
|
Some(Ok(remaining_input))
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests
|
|
{
|
|
use super::*;
|
|
|
|
#[test]
|
|
fn parse_variable_name()
|
|
{
|
|
assert_eq!(variable_name("X").unwrap(), ("X", ""));
|
|
assert_eq!(variable_name("_X").unwrap(), ("_X", ""));
|
|
assert_eq!(variable_name("__X").unwrap(), ("__X", ""));
|
|
assert_eq!(variable_name("Variable").unwrap(), ("Variable", ""));
|
|
assert_eq!(variable_name("_Variable").unwrap(), ("_Variable", ""));
|
|
assert_eq!(variable_name("__Variable").unwrap(), ("__Variable", ""));
|
|
assert_eq!(variable_name("X,").unwrap(), ("X", ","));
|
|
assert_eq!(variable_name("_X,").unwrap(), ("_X", ","));
|
|
assert_eq!(variable_name("__X,").unwrap(), ("__X", ","));
|
|
assert_eq!(variable_name("Variable,").unwrap(), ("Variable", ","));
|
|
assert_eq!(variable_name("_Variable,").unwrap(), ("_Variable", ","));
|
|
assert_eq!(variable_name("__Variable,").unwrap(), ("__Variable", ","));
|
|
}
|
|
|
|
#[test]
|
|
fn parse_variable_declaration()
|
|
{
|
|
let v = variable_declaration("X").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("X", ""));
|
|
let v = variable_declaration("_X").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("_X", ""));
|
|
let v = variable_declaration("__X").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("__X", ""));
|
|
let v = variable_declaration("Variable").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("Variable", ""));
|
|
let v = variable_declaration("_Variable").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("_Variable", ""));
|
|
let v = variable_declaration("__Variable").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("__Variable", ""));
|
|
let v = variable_declaration("X,").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("X", ","));
|
|
let v = variable_declaration("_X,").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("_X", ","));
|
|
let v = variable_declaration("__X,").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("__X", ","));
|
|
let v = variable_declaration("Variable,").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("Variable", ","));
|
|
let v = variable_declaration("_Variable,").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("_Variable", ","));
|
|
let v = variable_declaration("__Variable,").unwrap();
|
|
assert_eq!((v.0.name.as_str(), v.1), ("__Variable", ","));
|
|
}
|
|
|
|
#[test]
|
|
fn parse_variable_declarations()
|
|
{
|
|
let v = variable_declarations("X.").unwrap().unwrap();
|
|
assert_eq!(v.0.len(), 1);
|
|
assert_eq!(v.0[0].name.as_str(), "X");
|
|
assert_eq!(v.1, ".");
|
|
|
|
let v = variable_declarations("X,Y,Z.").unwrap().unwrap();
|
|
assert_eq!(v.0.len(), 3);
|
|
assert_eq!(v.0[0].name.as_str(), "X");
|
|
assert_eq!(v.0[1].name.as_str(), "Y");
|
|
assert_eq!(v.0[2].name.as_str(), "Z");
|
|
assert_eq!(v.1, ".");
|
|
|
|
let v = variable_declarations("X, Y, Z.").unwrap().unwrap();
|
|
assert_eq!(v.0.len(), 3);
|
|
assert_eq!(v.0[0].name.as_str(), "X");
|
|
assert_eq!(v.0[1].name.as_str(), "Y");
|
|
assert_eq!(v.0[2].name.as_str(), "Z");
|
|
assert_eq!(v.1, ".");
|
|
|
|
let v = variable_declarations("X , Y , Z.").unwrap().unwrap();
|
|
assert_eq!(v.0.len(), 3);
|
|
assert_eq!(v.0[0].name.as_str(), "X");
|
|
assert_eq!(v.0[1].name.as_str(), "Y");
|
|
assert_eq!(v.0[2].name.as_str(), "Z");
|
|
assert_eq!(v.1, ".");
|
|
|
|
assert!(variable_declarations("test").unwrap().is_none());
|
|
assert!(variable_declarations("X, test").is_err());
|
|
assert!(variable_declarations("X ,test").is_err());
|
|
assert!(variable_declarations("X,Y,Z, test").is_err());
|
|
assert!(variable_declarations("X,Y,Z ,test").is_err());
|
|
}
|
|
}
|