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Task/Call-a-function/Lambdatalk/call-a-function.lambdatalk

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+The command
+
+replace   :a0 :a1 ... an-1
+     in   expression containing some occurences of :ai
+     by   v0 v1 ... vp-1
+
+is rewritten in a prefixed parenthesized form
+
+{{lambda {:a0 :a1 ... an-1}
+          expression containing some occurences of :ai}
+          v0 v1 ... vp-1}
+
+so called IIFE (Immediately Invoked Function Expression), and defines an anonymous function containing a sequence of n arguments :ai, immediately invoked on a sequence of p values vi, and returning the expression in its body as so modified:
+
+1) if p < n     (partial application)
+
+• the occurrences of the p first arguments are replaced in the function's body by the corresponding p given values,
+• a function waiting for missing n-p values is created,
+• and its reference is returned.
+• example:
+{{lambda {:x :y} ... :y ... :x ...} hello}
+-> {lambda {:y} ... :y ... hello ...}    // replaces :x by hello
+-> LAMB_123                              // the new functions's reference
+• called with the value world this function will return ... world ... hello ...
+
+2) if p = n     (normal application)
+
+• the occurences of the n arguments are replaced in the function's body by the corresponding p given values,
+• the body is evaluated and the result is returned.
+• example
+{{lambda {:x :y} ... :y ... :x ...} hello world}
+-> {{lambda {:y} ... :y ... hello ...} world}  // replaces :x by hello
+-> {{lambda {} ... world ... hello ...} }      // replaces :y by world
+->             ... world ... hello ...         // the value
+
+3) if p > n    (variadicity)
+
+• the occurrences of the n-1 first arguments are replaced in the function's body by the corresponding n-1 given values,
+• the occurrences of the last argument are replaced in the body by the sequence of p-n supernumerary values,
+• the body is evaluated and the result is returned.
+• example:
+{{lambda {:x :y} ... :y ... :x ...} hello world good morning}
+-> {{lambda {:y} ... :y ... hello ...} world good morning}
+-> {{lambda {} ... world good morning ... hello ...}}
+->             ... world good morning ... hello ...        // the value
+
+More can be seen in http://lambdaway.free.fr/lambdawalks/?view=lambda