Function evaluteExpression

src/preprocessor/preprocessor.ts:311–412

(node: PreprocessorAstNode, macros: Macros)

// TODO: Are all of these operators equivalent between javascript and GLSL?
const evaluteExpression = (node: PreprocessorAstNode, macros: Macros) =>
  evaluate(node, {
    // TODO: Handle non-base-10 numbers. Should these be parsed in the peg grammar?
    int_constant: (node) => parseInt(node.token, 10),
    unary_defined: (node) => node.identifier.identifier in macros,
    identifier: (node) => node.identifier,
    group: (node, visit) => visit(node.expression),
    binary: ({ left, right, operator: { literal } }, visit) => {
      switch (literal) {
        // multiplicative
        case '*': {
          return visit(left) * visit(right);
        }
        // division
        case '/': {
          return visit(left) / visit(right);
        }
        // modulo
        case '%': {
          return visit(left) % visit(right);
        }
        // addition
        case '+': {
          return visit(left) + visit(right);
        }
        // subtraction
        case '-': {
          return visit(left) - visit(right);
        }
        // bit-wise shift
        case '<<': {
          return visit(left) << visit(right);
        }
        // bit-wise shift
        case '>>': {
          return visit(left) >> visit(right);
        }
        case '<': {
          return visit(left) < visit(right);
        }
        case '>': {
          return visit(left) > visit(right);
        }
        case '<=': {
          return visit(left) <= visit(right);
        }
        case '>=': {
          return visit(left) >= visit(right);
        }
        case '==': {
          return visit(left) == visit(right);
        }
        case '!=': {
          return visit(left) != visit(right);
        }
        // bit-wise and
        case '&': {
          return visit(left) & visit(right);