Concurrent incremental attribute evaluation

The design of a concurrent incremental combined static/dynamic attribute evaluator is presented. The static part is an incremental version of the ordered attribute evaluation scheme. The dynamic part is an incremental version of the dynamic evaluation scheme.To remove the restriction that every transformation of an attributed syntax tree should immediately be followed by a reevaluation of the tree, criteria have been formulated which permit a delay in calling the reevaluator. These criteria allow multiple asynchronous tree transformations and multiple asynchronous reevaluations. Transformation and reevaluation processes are distributed over regions of the tree. Each region is either in its transformation phase or in its reevaluation phase. Different regions can be in different phases at the same time

Determinants of door-in-door-out time in patients with ischaemic stroke transferred for endovascular thrombectomy

Background: Long door-in-door-out (DIDO) times are an important cause of treatment delay in patients transferred for endovascular thrombectomy (EVT) from primary stroke centres (PSC) to an intervention centre. Insight in causes of prolonged DIDO times may facilitate process improvement interventions. We aimed to quantify different components of DIDO time and to identify determinants of DIDO time. Methods: We performed a retrospective cohort study in a Dutch ambulance region consisting of six PSCs and one intervention centre. We included consecutive adult patients with anterior circulation large vessel occlusion, transferred from a PSC for EVT between October 1, 2019 and November 31, 2020. We subdivided DIDO into several time components and quantified contribution of these components to DIDO time. We used univariable and multivariable linear regression models to explore associations between potential determinants and DIDO time. Results: We included 133 patients. Median (IQR) DIDO time was 66 (52–83) min. The longest component was CTA-to-ambulance notification time with a median (IQR) of 24 (16–37) min. DIDO time increased with age (6 min per 10 years, 95% CI: 2–9), onset-to-door time outside 6 h (20 min, 95% CI: 5–35), M2-segment occlusion (15 min, 95% CI: 4–26) and right-sided ischaemia (12 min, 95% CI: 2–21). Conclusions: The CTA-to-ambulance notification time is the largest contributor to DIDO time. Higher age, onset-to-door time longer than 6 h, M2-segment occlusion and right-sided occlusions are independently associated with a longer DIDO time. Future interventions that aim to decrease DIDO time should take these findings into account.</p

Concurrent incremental attribute evaluation

The design of a concurrent incremental combined static/dynamic attribute evaluator is presented. The static part is an incremental version of the ordered attribute evaluation scheme. The dynamic part is an incremental version of the dynamic evaluation scheme. To remove the restriction that every transformation of an attributed syntax tree should immediately be followed by a reevaluation of the tree, criteria have been formulated which permit a delay in calling the reevaluator. These criteria allow multiple asynchronous tree transformations and multiple asynchronous reevaluations. Transformation and reevaluation processes are distributed over regions of the tree. Each region is either in its transformation phase or in its reevaluation phase. Different regions can be in different phases at the same time

Student Language Development Environment: the Slade companion version 2.8

Building a compiler can only really be understood by doing it. However, writing a compiler by hand is labour-intensive, time-consuming and error-prone. To automate this process, a compiler-writing system called SLADE, which stands for Student Language Development Environment, has been developed. This book consists of a tutorial on SLADE, comprising 8 lessons, and a reference guide for SLADE . The reference guide provides a detailed description of the Application Programming Interface, the underlying Virtual Machine (including the virtual instruction set), and a code interpreter. An on-line help is provided in SLADE that is closely related to the contents of this book

Attributed Abstract Program Trees

Traditionally, an attribute grammar is presented as a context-free grammar which is augmented with attributes and attribute evaluation rules. This makes attribute grammars a suitable means for the specification of the semantics of programming languages in the context of derivation trees. For the specification of semantic integrity constraints in the context of abstract program trees the concept of attribute grammars has to be re-defined. For this purpose, a language for the specification of context-free tree grammars is defined. This language is extended to an attribute tree grammar specification language