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Allegro CL |
3.1 Evaluation  3.1.2 The Evaluation Model 3.1.2.1 Form Evaluation 3.1.2.1.1 Symbols as Forms
3.1.2.1.1.1 Lexical VariablesA lexical variable is a variable that can be referenced only within the lexical scope of the form that establishes that variable; lexical variables have lexical scope. Each time a form creates a lexical binding of a variable, a fresh binding is established.Within the scope of a binding for a lexical variable name, uses of that name as a variable are considered to be references to that binding except where the variable is shadowed2 by a form that establishes a fresh binding for that variable name, or by a form that locally declares the name special. A lexical variable always has a value. There is no operator that introduces a binding for a lexical variable without giving it an initial value, nor is there any operator that can make a lexical variable be unbound. Bindings of lexical variables are found in the lexical environment. |