TY - JOUR A1 - Giannini, Paola A1 - Richter, Tim A1 - Servetto, Marco A1 - Zucca, Elena T1 - Tracing sharing in an imperative pure calculus JF - Science of computer programming N2 - We introduce a type and effect system, for an imperative object calculus, which infers sharing possibly introduced by the evaluation of an expression, represented as an equivalence relation among its free variables. This direct representation of sharing effects at the syntactic level allows us to express in a natural way, and to generalize, widely-used notions in literature, notably uniqueness and borrowing. Moreover, the calculus is pure in the sense that reduction is defined on language terms only, since they directly encode store. The advantage of this non-standard execution model with respect to a behaviorally equivalent standard model using a global auxiliary structure is that reachability relations among references are partly encoded by scoping. (C) 2018 Elsevier B.V. All rights reserved. KW - Imperative calculi KW - Sharing KW - Type and effect systems Y1 - 2018 U6 - https://doi.org/10.1016/j.scico.2018.11.007 SN - 0167-6423 SN - 1872-7964 VL - 172 SP - 180 EP - 202 PB - Elsevier CY - Amsterdam ER -