Analysis of information sources in references of the Wikipedia article "模式匹配" in Chinese language version.
John Darlington’s NPL, “New Programming Language”, developed with Burstall in the period 1973-5, replaced case expressions with multi-equation function definitions over algebraic types, including natural numbers, e.g.
fib (0) <= 1
fib (1) <= 1
fib (n+2) <= fib (n+1) + fib (n)
Darlington got this idea from Kleene’s recursion equations.
Miranda had, instead of conditional expressions, conditional equations with guards. Example:
sign x = 1, if x>0
= -1, if x<0
= 0, if x=0
Combining pattern matching with guards gives a significant gain in expressive power. Guards of this kind first appeared in KRC, “Kent Recursive Calculator”(Turner 1981, 1982), a miniaturised version of SASL which I designed in 1980–81 for teaching.
John Darlington’s NPL, “New Programming Language”, developed with Burstall in the period 1973-5, replaced case expressions with multi-equation function definitions over algebraic types, including natural numbers, e.g.
fib (0) <= 1
fib (1) <= 1
fib (n+2) <= fib (n+1) + fib (n)
Darlington got this idea from Kleene’s recursion equations.
Miranda had, instead of conditional expressions, conditional equations with guards. Example:
sign x = 1, if x>0
= -1, if x<0
= 0, if x=0
Combining pattern matching with guards gives a significant gain in expressive power. Guards of this kind first appeared in KRC, “Kent Recursive Calculator”(Turner 1981, 1982), a miniaturised version of SASL which I designed in 1980–81 for teaching.
