Struct StackFrame

pub struct StackFrame<'g, 'p, 'l>
where
    'g: 'p,
    'p: 'l,
{
    pub config: &'g Config<'g>,
    /* private fields */
}

Keeps track of variables and provides access to definitions from parent nodes

Example:

use diskplan_schema::DirectorySchema;
use diskplan_traversal::{StackFrame, VariableSource};

// The stack lifetimes allow us to have a function that takes a stack...
fn __<'g>(stack: &StackFrame<'g, '_, '_>, d: &'g DirectorySchema) {
    // ...provides access to items referenced by parent scopes...
    let var = stack.lookup(&"variable".into()).unwrap();

    // ...can be extended with a mutable local scope...
    let mut local = stack.push(VariableSource::Directory(d));

    // ...and capture local modifications...
    let owner = "root";
    local.put_owner(owner);
}

Fields

config: &'g Config<'g>

A reference to the shared config

Implementations

impl<'g, 'p, 'l> StackFrame<'g, 'p, 'l>

pub fn stack( config: &'g Config<'g>, variables: VariableSource<'g>, owner: &'l str, group: &'l str, mode: Mode, ) -> Self

Constructs a new stack

pub fn push<'s, 'r>( &'s self, variables: VariableSource<'g>, ) -> StackFrame<'g, 'r, 'r>

where 'g: 'r, 's: 'r,

Adds a new scope onto the stack, returning it

pub fn put_owner(&mut self, owner: &'l str)

Changes the owner in the current scope

pub fn put_group(&mut self, group: &'l str)

Changes the group in the current scope

pub fn owner(&self) -> &'l str

Returns the owner in the current scope

pub fn group(&self) -> &'l str

Returns the group in the current scope

pub fn mode(&self) -> Mode

Returns the UNIX permissions set for the current scope

pub fn variables(&self) -> &VariableSource<'l>

Provides access to variables in the current scope

pub fn lookup<'a>(&'a self, var: &Identifier<'a>) -> Option<Value<'a>>

Looks up the value of a variable in the current or parent scope(s)

pub fn find_definition<'a>( &self, var: &Identifier<'a>, ) -> Option<&'a SchemaNode<'g>>

Looks up the definition of a sub-schema in the current or parent scope(s)

Trait Implementations

impl Display for StackFrame<'_, '_, '_>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.