Add assignment resolving

This commit is contained in:
Casey Rodarmor 2016-10-29 20:39:21 -07:00
parent 362158d1da
commit 810365f22b
2 changed files with 134 additions and 39 deletions

12
notes
View File

@ -7,6 +7,15 @@ notes
and a evaluate recipe phase that runs when a recipe is run
and produces the evaluated lines
- --debug tests that:
- should consider renaming it to --evaluate if it actually evaluates stuff
- test values of assignments
- test values of interpolations
- remove evaluated_lines field from recipe
- change unknown variable to undefined variable
- save result of commands in variables
. backticks: `echo hello`
. backticks in assignments are evaluated before the first recipe is run
@ -20,6 +29,8 @@ notes
. eval shebang recipes all at once, but plain recipes line by line
. we want to avoid executing backticks before we need them
- --debug mode will evaluate everything and print values after assignments and interpolation expressions
- nicely convert a map to option string to a map to string
- set variables from the command line:
@ -54,6 +65,7 @@ notes
easier to accept a program that you once rejected than to
no longer accept a program or change its meaning
. habit of using clever commands and writing little scripts
. debugging with --debug or --evaluate
. very low friction to write a script (no new file, chmod, add to rcs)
. make list of contributors, include travis
. alias .j='just --justfile ~/.justfile --working-directory ~'

View File

@ -284,7 +284,11 @@ impl<'a> Display for Recipe<'a> {
}
}
fn resolve<'a>(recipes: &BTreeMap<&'a str, Recipe<'a>>) -> Result<(), Error<'a>> {
fn resolve_recipes<'a>(
recipes: &BTreeMap<&'a str, Recipe<'a>>,
assignments: &BTreeMap<&'a str, Expression<'a>>,
text: &'a str,
) -> Result<(), Error<'a>> {
let mut resolver = Resolver {
seen: HashSet::new(),
stack: vec![],
@ -296,6 +300,40 @@ fn resolve<'a>(recipes: &BTreeMap<&'a str, Recipe<'a>>) -> Result<(), Error<'a>
try!(resolver.resolve(&recipe));
}
for recipe in recipes.values() {
for line in &recipe.lines {
for fragment in line {
if let Fragment::Expression{ref expression, ..} = *fragment {
for variable in expression.variables() {
let name = variable.lexeme;
if !(assignments.contains_key(name) || recipe.arguments.contains(&name)) {
// There's a borrow issue here that seems too difficult to solve.
// The error derived from the variable token has too short a lifetime,
// so we create a new error from its contents, which do live long
// enough.
//
// I suspect the solution here is to give recipes, pieces, and expressions
// two lifetime parameters instead of one, with one being the lifetime
// of the struct, and the second being the lifetime of the tokens
// that it contains
let error = variable.error(ErrorKind::UnknownVariable{variable: name});
return Err(Error {
text: text,
index: error.index,
line: error.line,
column: error.column,
width: error.width,
kind: ErrorKind::UnknownVariable {
variable: &text[error.index..error.index + error.width.unwrap()],
}
});
}
}
}
}
}
}
Ok(())
}
@ -303,7 +341,7 @@ struct Resolver<'a: 'b, 'b> {
stack: Vec<&'a str>,
seen: HashSet<&'a str>,
resolved: HashSet<&'a str>,
recipes: &'b BTreeMap<&'a str, Recipe<'a>>
recipes: &'b BTreeMap<&'a str, Recipe<'a>>,
}
impl<'a, 'b> Resolver<'a, 'b> {
@ -340,6 +378,81 @@ impl<'a, 'b> Resolver<'a, 'b> {
}
}
fn resolve_assignments<'a>(
assignments: &BTreeMap<&'a str, Expression<'a>>,
assignment_tokens: &BTreeMap<&'a str, Token<'a>>,
) -> Result<(), Error<'a>> {
let mut resolver = AssignmentResolver {
assignments: assignments,
assignment_tokens: assignment_tokens,
stack: vec![],
seen: HashSet::new(),
evaluated: HashSet::new(),
};
for name in assignments.keys() {
try!(resolver.resolve_assignment(name));
}
Ok(())
}
struct AssignmentResolver<'a: 'b, 'b> {
assignments: &'b BTreeMap<&'a str, Expression<'a>>,
assignment_tokens: &'b BTreeMap<&'a str, Token<'a>>,
stack: Vec<&'a str>,
seen: HashSet<&'a str>,
evaluated: HashSet<&'a str>,
}
impl<'a: 'b, 'b> AssignmentResolver<'a, 'b> {
fn resolve_assignment(&mut self, name: &'a str) -> Result<(), Error<'a>> {
if self.evaluated.contains(name) {
return Ok(());
}
self.seen.insert(name);
self.stack.push(name);
if let Some(expression) = self.assignments.get(name) {
try!(self.resolve_expression(expression));
self.evaluated.insert(name);
} else {
panic!();
}
Ok(())
}
fn resolve_expression(&mut self, expression: &Expression<'a>) -> Result<(), Error<'a>> {
match *expression {
Expression::Variable{name, ref token} => {
if self.evaluated.contains(name) {
return Ok(());
} else if self.seen.contains(name) {
let token = self.assignment_tokens.get(name).unwrap();
self.stack.push(name);
return Err(token.error(ErrorKind::CircularVariableDependency {
variable: name,
circle: self.stack.clone(),
}));
} else if self.assignments.contains_key(name) {
try!(self.resolve_assignment(name));
} else {
return Err(token.error(ErrorKind::UnknownVariable{variable: name}));
}
}
Expression::String{..} => {}
Expression::Backtick{..} => {}
Expression::Concatination{ref lhs, ref rhs} => {
try!(self.resolve_expression(lhs));
try!(self.resolve_expression(rhs));
}
}
Ok(())
}
}
fn evaluate<'a>(
assignments: &BTreeMap<&'a str, Expression<'a>>,
assignment_tokens: &BTreeMap<&'a str, Token<'a>>,
@ -1420,7 +1533,7 @@ impl<'a> Parser<'a> {
}))
}
try!(resolve(&recipes));
try!(resolve_recipes(&recipes, &assignments, self.text));
for recipe in recipes.values() {
for argument in &recipe.argument_tokens {
@ -1439,39 +1552,9 @@ impl<'a> Parser<'a> {
}));
}
}
}
for line in &recipe.lines {
for piece in line {
if let Fragment::Expression{ref expression, ..} = *piece {
for variable in expression.variables() {
let name = variable.lexeme;
if !(assignments.contains_key(&name) || recipe.arguments.contains(&name)) {
// There's a borrow issue here that seems to difficult to solve.
// The error derived from the variable token has too short a lifetime,
// so we create a new error from its contents, which do live long
// enough.
//
// I suspect the solution here is to give recipes, pieces, and expressions
// two lifetime parameters instead of one, with one being the lifetime
// of the struct, and the second being the lifetime of the tokens
// that it contains
let error = variable.error(ErrorKind::UnknownVariable{variable: name});
return Err(Error {
text: self.text,
index: error.index,
line: error.line,
column: error.column,
width: error.width,
kind: ErrorKind::UnknownVariable {
variable: &self.text[error.index..error.index + error.width.unwrap()],
}
});
}
}
}
}
}
}
try!(resolve_assignments(&assignments, &assignment_tokens));
let values =
try!(evaluate(&assignments, &assignment_tokens, &mut recipes));