Struct WalkCtx 

struct WalkCtx<'a> {
    src: &'a str,
    scopes: Vec<HashMap<String, WgslType>>,
    edits: Vec<TextEdit>,
}

AST walker state: a small stacked symbol table plus a sink for text edits. Each walk_* consults and updates the table; walk_expr returns the inferred type of the expression so callers can decide whether to emit a fix-up edit.

Fields

src: &'a str

scopes: Vec<HashMap<String, WgslType>>

edits: Vec<TextEdit>

Implementations

impl<'a> WalkCtx<'a>

fn new(src: &'a str) -> Self

fn seed_globals(&mut self, tu: &TranslationUnit)

fn scope_push(&mut self)

fn scope_pop(&mut self)

fn declare(&mut self, name: &str, ty: WgslType)

fn lookup(&self, name: &str) -> WgslType

fn slice(&self, span: Span) -> &'a str

Slice of original source between span bounds.

fn emit_truncation(&mut self, span: Span, target_size: usize)

fn emit_pad_vec2_to_vec3(&mut self, span: Span)

Wrap a vec2 expression in vec3<f32>(<expr>, 0.0) so it satisfies a helper that demands a vec3 (real example: MD2 presets calling lum(roam_sin.yx) where the runtime padded implicitly). Emitted as two zero-length insertions instead of one replace-range edit so any inner edits inside the arg (e.g. a swizzle rewrite) don’t get dropped by apply_edits’s overlap guard.

fn emit_scalar_to_vec2(&mut self, span: Span)

Wrap a scalar expression in vec2<f32>(<expr>) so it satisfies a 2D-texture coord parameter. MD2 presets occasionally pass a single channel (tex2D(sampler_noise_hq, uv.x)) where naga demands a vec2; HLSL silently broadcast in that situation. Emitted as two zero-length insertions, same overlap-safety rationale as Self::emit_pad_vec2_to_vec3.