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Scope modifiers: Difference between revisions
→{{header|Common Lisp}}: global functions within LETs are rarely used. Replaced with local function.
Underscore (talk | contribs) (→{{header|R}}: Linked to an enlightening blog post.) |
(→{{header|Common Lisp}}: global functions within LETs are rarely used. Replaced with local function.) |
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Line 184:
(let ((shape "triangle") (*bug* "ant"))
(
(format t "~% There is some ~A in my ~A!" *bug* shape)))
(format t "~%Put ~A in your ~A..." *bug* shape)
(speak
(let ((shape "circle") (*bug* "cockroach"))▼
(format t "~%Put ~A in your ~A..." *bug* shape)▼
(speak))))</lang>▼
The
▲(let ((shape "circle") (*bug* "cockroach"))
▲ (format t "~%Put ~A in your ~A..." *bug* shape)
▲ (speak))</lang>
▲The global function <code>speak</code> tries to use both <code>*bug*</code> and <code>shape</code>. For lexical scope, the value comes from where the program ''defines'' <code>speak</code>. For dynamic scope, the value comes from where the program ''calls'' <code>speak</code>. So <code>speak</code> always uses the same "triangle", but can use a different bug.
<pre>Put ant in your triangle...
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