如何更改big_step_Decls (Proc p s)
以遵循静态范围规则并匹配proc类型?
这是我要实现的静态proc声明的规则:
<decls, env [p -> (s, env)] --> <sto', env'>
------------------------------------------------
<proc p is s : decls, env, sto > --> <sto', env'>
这是Haskell代码的片段,用于变量和过程声明的大步语义。
data Env = Env {var :: Map String Loc, proc :: Map String (Stm, Env)} deriving Show
env0 = Env { var = empty, proc = empty}
big_step_Decls :: ([Decl], Env, Sto) -> (Env, Sto)
big_step_Decls ([], env, sto) = (env, sto)
big_step_Decls ((VarD x a): more_decls, env, sto) = (env', sto')
where v = big_step_a env sto a'
(l, sto'') = alloc sto
env'' = env {var = insert x l (var env)}
(env', sto') = big_step_Decls (more_decls, env'', insert l v sto'')
big_step_Decls ((Proc p s): more_decls, env, sto) = (env',sto')
where env'' = env {proc = insert p s (proc env)}
(env', sto') = big_step_Decls (more_decls, env'', sto)
这是我遇到的错误(PS:我是Haskell的新手,仍在尝试弄清楚基础知识。)
BIPs.hs:161:31: error:
* Couldn't match type `Stm' with `(Stm, Env)'
Expected type: Map String (Stm, Env)
Actual type: Map String Stm
* In the `proc' field of a record
In the expression: env {proc = (insert p s) (proc env)}
In an equation for env'':
env'' = env {proc = (insert p s) (proc env)}
|
161 | where env'' = env {proc = (insert p s) (proc env)}
| ^^^^^^^^^^^^^^^^^^^^^^^
BIPs.hs:161:45: error:
* Couldn't match type `(Stm, Env)' with `Stm'
Expected type: Map String Stm
Actual type: Map String (Stm, Env)
* In the third argument of `insert', namely `(proc env)'
In the `proc' field of a record
In the expression: env {proc = (insert p s) (proc env)}
|
161 | where env'' = env {proc = (insert p s) (proc env)}
| ^^^^^^^^
Failed, no modules loaded.
在此表达式中,env'' = env {proc = (insert p s) (proc env)}
p
是映射键,s
是值。 proc
映射中的值的类型为(Stm, Env)
,但是您当前正在尝试仅插入类型为s
的Stm
。