diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 90 |
1 files changed, 75 insertions, 15 deletions
@@ -20889,11 +20889,16 @@ leftmost argument, so that the function has access to the object. .coNP Macro @ meth .synb -.mets (meth < struct << slot ) +.mets (meth < struct < slot << curried-expr *) .syne .desc The .code meth +macro allows indirection upon a method-like function stored +in a function slot. + +The +.code meth macro binds .meta struct as the leftmost argument of the function stored in @@ -20903,16 +20908,49 @@ That is to say, it returns a function .meta f such that .cblk -.meti >> ( f < arg ... ) +.meti >> [ f < arg ... ] .cble calls .cblk -.meti >> ( struct.slot < struct < arg ... ) +.meti >> [ struct.slot < struct < arg ... ] .cble except that .meta struct is evaluated only once. +If one or more +.meta curried-expr +expressions are present, their values are bound inside +.meta f +also, and when +.meta f +is invoked, these are passed to the function stored in the slot. +Thus if +.meta f +is produced by +.code "(meth struct slot c1 c2 c3 ...)" +then +.cblk +.meti >> [ f < arg ... ] +.cble +calls +.cblk +.meti >> [ struct.slot < struct < c1v < c2v < c3v ... arg ... ] +.cble +.cble +except that +.meta struct +is evaluated only once, and +.metn c1v , +.meta c2v +and +.meta c3v +are the values of expressions +.codn c1 , +.code c2 +and +.codn c3 . + The argument .meta struct must be an expression which evaluates to a struct. @@ -20927,10 +20965,20 @@ function: (meth a b) <--> (method a 'b) .cble -The -.code meth -macro allows indirection upon a method-like function stored -in a function slot. +If +.meta curried-arg +expressions are present, the translation may be be understood +as: + +.cblk + (meth a b c1 c2 ...) <--> [(fun method) a 'b c1 c2 ...] +.cble + +In other words the +.meta curried-arg +expressions are evaluated under the +.code dwim +operator evaluation rules. .TP* Example: @@ -21547,14 +21595,20 @@ The return value is .coNP Function @ method .synb -.mets (method < struct-obj << slot-name ) +.mets (method < struct-obj < slot-name << curried-arg *) .syne .desc The .code method -function retrieves a function from a structure's slot -and binds that function's left argument to the -structure. +function retrieves a function +.meta m +from a structure's slot +and returns a new function which binds that function's +left argument. If +.meta curried-arg +arguments are present, then they are also stored in +the returned function. These are the +.IR "curried arguments" . The .meta struct-obj @@ -21564,13 +21618,19 @@ must be a symbol denoting a slot in that structure. The slot must hold a function of at least one argument. -The +The function +.meta f +which .code method -function returns a function which, when invoked, -calls the function previously retrieved from the object's +function returns, when invoked, +calls the function +.meta m +previously retrieved from the object's slot, passing to that function .meta struct-obj -as the leftmost argument, followed by the function's +as the leftmost argument, followed by the curried +arguments, followed by all of +.metn f 's own arguments. Note: the |