Function typeAssignable

packages/language/src/utils.ts:85–103

(destType: ExpressionType, sourceType: ExpressionType, sourceExpr?: Expression)

 * Determines if the given sourceType is assignable to a destination of destType
 */
export function typeAssignable(destType: ExpressionType, sourceType: ExpressionType, sourceExpr?: Expression): boolean {
    // implicit conversion from ISO datetime string to datetime
    if (destType === 'DateTime' && sourceType === 'String' && sourceExpr && isStringLiteral(sourceExpr)) {
        const literal = getStringLiteral(sourceExpr);
        if (literal && isoDateTimeRegex.test(literal)) {
            // implicitly convert to DateTime
            sourceType = 'DateTime';
        }
    }

    switch (destType) {
        case 'Any':
            return true;
        case 'Float':
            return sourceType === 'Any' || sourceType === 'Int' || sourceType === 'Float';
        default:
            return sourceType === 'Any' || sourceType === destType;
    }
}

/**
 * Maps a ZModel builtin type to expression type