Enum Expr 

pub enum Expr {
    Literal(Value),
    Variable(String),
    GetAttr {
        base: Box<Expr>,
        attr: String,
    },
    GetItem {
        base: Box<Expr>,
        index: Box<Expr>,
    },
    Slice {
        start: Option<Box<Expr>>,
        stop: Option<Box<Expr>>,
        step: Option<Box<Expr>>,
    },
    Call {
        callee: Box<Expr>,
        args: Vec<Expr>,
        kwargs: Vec<(String, Expr)>,
    },
    Filter {
        name: String,
        input: Box<Expr>,
        args: Vec<Expr>,
    },
    List(Vec<Expr>),
    Dict(Vec<(Expr, Expr)>),
    InlineIf {
        cond: Box<Expr>,
        then_expr: Box<Expr>,
        else_expr: Option<Box<Expr>>,
    },
    Unary {
        op: UnaryOp,
        expr: Box<Expr>,
    },
    Binary {
        op: BinOp,
        left: Box<Expr>,
        right: Box<Expr>,
    },
    Compare {
        head: Box<Expr>,
        rest: Vec<(CompareOp, Expr)>,
    },
    RegexLiteral {
        pattern: String,
        flags: String,
    },
}

Expression inside a variable tag or tag body (when wired up).

Variants

Literal(Value)

JSON literal (numbers, strings, booleans, null).

Variable(String)

Context key; non-existent keys render as empty (Nunjucks-style).

GetAttr

Attribute access: base.attr (Nunjucks LookupVal).

Fields

base: Box<Expr>

attr: String

GetItem

Subscript: base[index] or Jinja-style base[start:stop:step].

Fields

base: Box<Expr>

index: Box<Expr>

Single index, or Expr::Slice for : subscripts.

Slice

Slice inside [ … ] (start:stop:step; any part may be omitted).

Fields

start: Option<Box<Expr>>

stop: Option<Box<Expr>>

step: Option<Box<Expr>>

Call

Function-style call callee(args…) (runtime may be limited until globals exist).

Fields

callee: Box<Expr>

args: Vec<Expr>

kwargs: Vec<(String, Expr)>

name = value arguments (applied after positionals; unknown names ignored, Nunjucks-style).

Filter

Filter pipeline step: input | name or input | name(arg, …).

Fields

name: String

input: Box<Expr>

args: Vec<Expr>

List(Vec<Expr>)

Array literal [a, b, …] with arbitrary expressions.

Dict(Vec<(Expr, Expr)>)

Object literal { key: val, …} (keys are expressions, usually strings or identifiers).

InlineIf

Python-style conditional: body if cond else else_.

Fields

cond: Box<Expr>

then_expr: Box<Expr>

else_expr: Option<Box<Expr>>

Unary

Fields

op: UnaryOp

expr: Box<Expr>

Binary

Fields

op: BinOp

left: Box<Expr>

right: Box<Expr>

Compare

Chained comparisons (a == b < c → left-associative JS-style emit in Nunjucks).

Fields

head: Box<Expr>

rest: Vec<(CompareOp, Expr)>

RegexLiteral

JavaScript-style regex literal r/pattern/flags (Nunjucks lexer).

Fields

pattern: String

Raw pattern body between slashes (may contain \/ escapes).

flags: String

Flag letters g, i, m, y (subset of ECMAScript).

Trait Implementations

impl Clone for Expr

fn clone(&self) -> Expr

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Expr

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

Formats the value using the given formatter.

impl PartialEq for Expr

fn eq(&self, other: &Expr) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Expr