Struct SymbolTable 

pub struct SymbolTable {
    pub locals: HashMap<String, WgslType>,
}

Maps locally-declared identifier → its WGSL type. Pre-seeded with the uniforms and helper-function bindings the codegen wrapper exposes inside fs_main (so that texsize, q1..q32, aspect, etc. resolve to known types).

Fields

locals: HashMap<String, WgslType>

Implementations

impl SymbolTable

pub fn from_source(src: &str) -> Self

Build a symbol table by scanning var NAME: TYPE / let NAME: TYPE declarations in the translated source. Pre-seeded with the wrapper preamble’s bindings so user code can be analysed in isolation.

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

pub fn infer_expr_type(&self, expr: &str) -> WgslType

Best-effort type inference for an expression text. Returns a confident type for the dominant patterns, WgslType::Unknown otherwise — callers must treat Unknown as “do not modify”.

Recognised:

• A numeric literal (with or without f/i/u suffix) → F32.
• A bare identifier in the symbol table → that type.
• A constructor call vec3<f32>(...) etc. → that type.
• A call to a known helper (GetPixel, GetBlur1..3, lum, textureSample, etc.) → its return type.
• A swizzle access <expr>.<comp> where the prefix is a vec type — narrowed to F32 for .x/.y/.z/.w/.r/.g/.b/.a of length 1, Vec2F for 2, Vec3F for 3, Vec4F for 4.
• A binary op (+, -, *, /) where one side is vec → the widest vec type. Falls back to F32 when both sides are scalar.