serum.core
and-letcljmacro
(and-let bindings expr)(and-let bindings expr else-expr)Derived from Scheme's and-let, this macro will evaluate expr should all of its bindings evaluate truthy.
Evaluates else-expr if any of the bindings evaluate falsey or returns nil if else-expr is not provided.
Evaluation of bindings ceases upon a falsey result.
bindings expects a binding-forms vector as in (let) and (loop) etc.
expr expression to be evaluated if bindings evaluate truthy
else-expr expression to be evaluated if any bindings evaluate falsey
Derived from Scheme's and-let, this macro will evaluate `expr` should all of its bindings evaluate truthy. Evaluates `else-expr` if any of the bindings evaluate falsey or returns nil if `else-expr` is not provided. Evaluation of `bindings` ceases upon a falsey result. `bindings` expects a binding-forms vector as in (let) and (loop) etc. `expr` expression to be evaluated if bindings evaluate truthy `else-expr` expression to be evaluated if any bindings evaluate falsey
attemptcljmacro
(attempt expr f)the expression expr will be executed in a try/catch form.
if an exception is caught, a handler function of one argument, f, will be executed
and will be passed the caught java exception object.
the expression `expr` will be executed in a try/catch form. if an exception is caught, a handler function of one argument, `f`, will be executed and will be passed the caught java exception object.
divertcljmacro
(divert & body)derived from (with-out-str). Evaluates body, captures any output destined to out, and returns result
of body and text output as a vector tuple, [~@body captured-output-string]
derived from (with-out-str). Evaluates body, captures any output destined to *out*, and returns result of `body` and text output as a vector tuple, [~@body captured-output-string]
do-onceclj
(do-once fun)Returns a closure which will execute the passed function, fun, once.
Subsequent calls will return cached results of the function call.
fun is expected to be a function without arguments.
The initial result of evaluating fun will always be returned.
Different caches can be maintained simply by using separate invocations of do-once
Returns a closure which will execute the passed function, `fun`, once. Subsequent calls will return cached results of the function call. `fun` is expected to be a function without arguments. The initial result of evaluating `fun` will always be returned. Different caches can be maintained simply by using separate invocations of `do-once`
fail-letcljmacro
(fail-let binding expr)conditional let form which expects binding expression to return a hashmap with {:success boolean} content.
fail-let supports a single binding pair: binding.
will evaluate 'expr' if (:success y#) is falsey.
passes binding symbol/value to expr.
conditional let form which expects binding expression to return a hashmap with {:success boolean} content.
`fail-let` supports a single binding pair: `binding`.
will evaluate 'expr' if (:success y#) is falsey.
passes binding symbol/value to `expr`.find-key-valclj
(find-key-val k v mapseq)searches mapseq for an element with a matching key/value pair.
The key is specified by k, and the value is specified by v.
searches `mapseq` for an element with a matching key/value pair. The key is specified by `k`, and the value is specified by `v`.
find-predclj
(find-pred pred coll)applies pred to each element of a collection, coll, until it returns a truthy value,
then returns the matching element (not the individual value). Compare with clojure.core/some
applies `pred` to each element of a collection, `coll`, until it returns a truthy value, then returns the matching element (*not* the individual value). Compare with `clojure.core/some`
set-var-rootclj
(set-var-root v value)convenience interface to clojure.core/alter-var-root.
with the semantic of clojure.core/reset!, will rebind a value, value to a var v.
v - a var reference (e.g. #'state-example).
value - new value to bind to var v.
convenience interface to `clojure.core/alter-var-root`. with the semantic of `clojure.core/reset!`, will rebind a value, `value` to a var `v`. `v` - a var reference (e.g. `#'state-example`). `value` - new value to bind to var `v`.
shiftclj
(shift f)(shift f arg2)(shift f arg2 arg3)(shift f arg2 arg3 arg4 & args)similar to partial, provides a modified interface to function f.
returns a function which accepts a single argument, always passing it as the first argument of f.
useful with (comp) and threading macros.
similar to partial, provides a modified interface to function `f`. returns a function which accepts a single argument, always passing it as the first argument of `f`. useful with (comp) and threading macros.
success-letcljmacro
(success-let binding expr)(success-let binding expr else-expr)conditional let form which expects binding expression to return a hashmap with {:success boolean} content.
success-let supports a single binding pair: binding.
will evaluate expr if (:success y#) is truthy.
will evaluate else if (:success y#) is falsey.
passes binding symbol/value to both expr and else-expr expressions.
conditional let form which expects binding expression to return a hashmap with {:success boolean} content.
`success-let` supports a single binding pair: `binding`.
will evaluate `expr` if (:success y#) is truthy.
will evaluate `else` if (:success y#) is falsey.
passes binding symbol/value to both `expr` and `else-expr` expressions.try-true?cljmacro
(try-true? expr)the expression expr is expected to be a validation form which returns booleanness.
expr will be executed in a try/catch form and a boolean returned.
caught exceptions will return false.
the expression `expr` is expected to be a validation form which returns booleanness. `expr` will be executed in a try/catch form and a boolean returned. caught exceptions will return false.
within?clj
(within? coll x)(within? coll fun x)is "x" in "coll"?
has signature and semantics of contains?.
matches elements rather than indices of indexed collections.
coll collection which is source of comparison.
x target comparison value.
fun comparison function (defaults to =).
within? has arguably more consistent semantics for collections than contains?:
(contains? [4 5 6] 4) => falsey
(contains? '(4 5 6) 4) => truthy
(within? [4 5 6] 4) => truthy
(within? '(4 5 6) 4) => truthy
is "x" in "coll"? has signature and semantics of `contains?`. matches elements rather than indices of indexed collections. `coll` collection which is source of comparison. `x` target comparison value. `fun` comparison function (defaults to `=`). `within?` has arguably more consistent semantics for collections than `contains?`: `(contains? [4 5 6] 4) => falsey` `(contains? '(4 5 6) 4) => truthy` `(within? [4 5 6] 4) => truthy` `(within? '(4 5 6) 4) => truthy`
wrap-within-fnclj
(wrap-within-fn fun)(wrap-within-fn compare-fn fun)convenience function which returns a lambda intended for within? comparisons.
fun to process all comparison arguments.
compare-fn function to perform comparison
convenience function which returns a lambda intended for `within?` comparisons. `fun` to process all comparison arguments. `compare-fn` function to perform comparison
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