Abstract: A system is provided for building a parser generator. The system includes a grammar input module for inputting in the parser generator a grammar expressed in a given formalism. A checking module formally verifies that a given grammar belongs to a predetermined class of grammars for which a translation to a correct, terminating parser is feasible. A checking module formally verifies that a grammar expressed in the formalism is well-formed. A semantic action module defines a parsing result depending on semantic actions embedded in the grammar. The semantic action module ensures in a formal way that all semantic actions of the grammar are terminating semantic actions. A formal module generates a parser with total correctness guarantees, using the modules to verify that the grammar is well-formed, belongs to a certain class of feasible, terminating grammars and all its semantic actions are terminating.

Abstract: A trip planning service allows users to easily edit and buy trips which consist of several items and elements. The trip planning service allows for editing a trip which respects a set of rules, such as rules that all nights have accommodations, scheduled visits are on intended days, etc. The trip planning service automatically updates elements to make them correct. In some examples, the trip planning service allows editing a trip in a single web page or interface screen through which the user interacts.

Abstract: The invention relates to a method for compiling a computer program written in a high-level programming language. In some examples, the method includes: a preliminary step of writing said program written in a high-level programming language including: a step of building a so-called PML functional basic language with reduced algebra and without re-allocation operations; a step of writing at least one library in a pre-existing language and, from said at least one library, the step of building functional interfaces from imperative functionalities be-longing to the group that includes at least: the perennial storage of information on a medium, the transmission and reception of packets on a network, and the analysis of a data flow; a step of building a high-level language by linking said interfaces in PML language functions; and a step of creating said computer program from the high-level language that includes a compilation step.