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38 lines
2.3 KiB
TeX
38 lines
2.3 KiB
TeX
% !TEX TS-program = pdflatex
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% !TeX spellcheck = en_US
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% !TEX root = lama-spec.tex
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\chapter{Introduction}
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\lama is a programming language developed by JetBrains Research for educational purposes as an exemplary language to introduce
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the domain of programming languages, compilers and tools. Its general characteristics are:
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\begin{itemize}
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\item procedural with first-class functions~--- functions can be passed as arguments, placed in data structures,
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returned and ``constructed'' at runtime via closure mechanism;
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\item with lexical static scoping;
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\item strict~--- all arguments of function application are evaluated before function body;
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\item imperative~--- variables can be re-assigned, function calls can have side effects;
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\item untyped~--- no static type checking is performed;
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\item with S-expressions and pattern-matching;
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\item with user-defined infix operators, including those defined in local scopes;
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\item with automatic memory management (garbage collection).
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\end{itemize}
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The name \lama is an acronym for $\lambda\textsc{-Algol}$ since the language has borrowed the syntactic shape of
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operators from \textsc{Algol-68}~\cite{A68}; \textsc{Haskell}~\cite{haskell} and \textsc{OCaml}~\cite{ocaml} can be
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mentioned as other languages of inspiration.
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The main purpose of \lama is to present a repertoire of constructs with certain runtime behavior and
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relevant implementation techniques. The lack of a type system (a vital feature for a real-word language
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for software engineering) is an intensional decision which allows to show the unchained diversity
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of runtime behaviors, including those which a typical type system is called to prevent. On the other hand
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the language can be used in future as a raw substrate to apply various ways of software verification (including
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type systems) on.
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The current implementation contains a native code compiler for \textsc{x86-64}, written
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in \textsc{OCaml}, a runtime library with garbage-collection support, written in \textsc{C}, and a small
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standard library, written in \lama itself.
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In addition, a source-level reference interpreter is implemented as well as a compiler to a small
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stack machine. The stack machine code can in turn be either interpreted on a stack machine interpreter, or
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used as an intermediate representation by the native code compiler.
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