Struct gpp::Context

pub struct Context {
    pub macros: HashMap<String, String>,
    pub inactive_stack: u32,
    pub used_if: bool,
    pub allow_exec: bool,
    pub in_stack: Vec<Child>,
}

Context of the current processing.

Contains a set of currently defined macros, as well as the number of nested if statements that are being ignored; this is so that if the parser failed an if statement, and it is currently ignoring data, it knows how many endifs it needs to encounter before resuming reading data again. Only if this value is 0 then the parser will read data. It also stores whether the current if group has been accepted; this is for if groups with over three parts.

There are no limits on what variable names can be; by directly altering Context::macros, you can set variable names not possible with #defines. However, when replacing variable names in text the variable name must be surrounded by two characters that are not alphanumeric or an underscore.

Fields

macros: HashMap<String, String>

Map of all currently defined macros.

inactive_stack: u32

Number of layers of inactive if statements.

used_if: bool

Whether the current if statement has been accepted.

allow_exec: bool

Whether #exec and #in commands are allowed.

in_stack: Vec<Child>

The stack of processes that #in is piping to.

Implementations

impl Context

pub fn new() -> Self

Create a new empty context with no macros or inactive stack and exec commands disallowed.

pub fn new_exec() -> Self

Create a new empty context with no macros or inactive stack and exec commands allowed.

pub fn from_macros(macros: impl Into<HashMap<String, String>>) -> Self

Create a context from a map of macros.

pub fn from_macros_iter(
    macros: impl IntoIterator<Item = (String, String)>
) -> Self

Create a context from an iterator over tuples.

pub fn exec(self, allow_exec: bool) -> Self

Set whther exec commands are allowed.

Trait Implementations

impl Debug for Context

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

Formats the value using the given formatter.

impl Default for Context

fn default() -> Context

Returns the “default value” for a type.