syntax (define/match1 函数名 函数体 ...)

> (define/match1 f     [1 2]     [_ 10])
> (f 1)
2
> (f 2)
10
> (define/match1 g     [1 (+ it it it)]     [_ 10])
> (g 1)
3
> (g 2)
10

syntax (define/match1/contract 函数名 contract-body 函数体 ...)

> (define/match1/contract f     (-> positive? positive?)     [1 2]     [_ -1])

> (f 1)

2

> (f 10)

f: broke its own contract

promised: positive?

produced: -1

in: the range of

(-> positive? positive?)

contract from: (function f)

blaming: (function f)

(assuming the contract is correct)

at: eval:10:0

syntax (define/match/contract (函数名 参数 ...) contract-body 函数体 ....)

> (define/match/contract (f a)     (-> positive? positive?)     [(1) 2]     [(_) -10])

> (f 1)

2

> (f 2)

f: broke its own contract

promised: positive?

produced: -10

in: the range of

(-> positive? positive?)

contract from: (function f)

blaming: (function f)

(assuming the contract is correct)

at: eval:13:0