rename cmd parse to argx to improve importing (#671)

- imports `*` are unnecessary
- shorter names for easier reference in task scripts
- `cmd` is too common and may cause potential conflicts

Co-authored-by: nash <nash@iffy.me>

modules/argx/argx.nu

@@ -0,0 +1,127 @@
+export def get-sign [cmd] {
+    let x = (scope commands | where name == $cmd).signatures?.0?.any?
+    mut s = []
+    mut n = {}
+    mut p = []
+    mut pr = []
+    mut r = []
+    for it in $x {
+        if $it.parameter_type == 'switch' {
+            if not ($it.short_flag | is-empty) {
+                $s ++= $it.short_flag
+            }
+            if not ($it.parameter_name | is-empty) {
+                $s ++= $it.parameter_name
+            }
+        } else if $it.parameter_type == 'named' {
+            if ($it.parameter_name | is-empty) {
+                $n = ($n | upsert $it.short_flag $it.short_flag)
+            } else if ($it.short_flag | is-empty) {
+                $n = ($n | upsert $it.parameter_name $it.parameter_name)
+            } else {
+                $n = ($n | upsert $it.short_flag $it.parameter_name)
+            }
+        } else if $it.parameter_type == 'positional' {
+            if $it.is_optional == false {
+                $p ++= $it.parameter_name
+            } else {
+                $pr ++= $it.parameter_name
+            }
+        } else if $it.parameter_type == 'rest' {
+            $r ++= $it.parameter_name
+        }
+    }
+    { switch: $s, name: $n, positional: ($p ++ $pr), rest: $r }
+}
+
+# "test -h [123 (3213 3)] 123 `a sdf` --cd --ef sadf -g" | token
+export def token [] {
+    let s = ($in | split row '' | range 1..-2)
+    let s = if ($s | last) == ' ' { $s } else { $s | append ' ' }
+    mut par = []
+    mut res = []
+    mut cur = ''
+    mut esc = false
+    for c in $s {
+        if $c == '\' {
+            $esc = true
+        } else {
+            if $esc {
+                $cur ++= $c
+                $esc = false
+            } else {
+                if $c == ' ' and ($par | length) == 0 {
+                    $res ++= [$cur]
+                    $cur = ''
+                } else {
+                    if $c in ['{' '[' '('] {
+                        $par ++= $c
+                    }
+                    if $c in ['}' ']' ')'] {
+                        $par = ($par | range ..-2)
+                    }
+                    if $c in ['"' "'" '`'] {
+                        if ($par | length) > 0 and ($par | last) == $c {
+                            $par = ($par | range ..-2)
+                        } else {
+                            $par ++= $c
+                        }
+                    }
+                    $cur ++= $c
+                }
+
+            }
+        }
+    }
+    return $res
+}
+
+export def parse [] {
+    let token = ($in | token)
+    let sign = (get-sign $token.0)
+    mut sw = ''
+    mut pos = []
+    mut opt = {}
+    for c in $token {
+        if ($sw | is-empty) {
+            if ($c | str starts-with '-') {
+                let c = if ($c | str substring 1..2) != '-' {
+                    let k = ($c | str substring 1..)
+                    if $k in $sign.name {
+                        $'($sign.name | get $k)'
+                    } else {
+                        $k
+                    }
+                } else {
+                    $c | str substring 2..
+                }
+                if $c in $sign.switch {
+                    $opt = ($opt | upsert $c true)
+                } else {
+                    $sw = $c
+                }
+            } else {
+                $pos ++= [$c]
+            }
+        } else {
+            $opt = ($opt | upsert $sw $c)
+            $sw = ''
+        }
+    }
+    $opt._args = $pos
+    let p = $pos | range 1..($sign.positional | length)
+    let rest = $pos | range (($sign.positional | length) + 1)..-1
+    $opt._pos = ( $p | enumerate
+        | reduce -f {} {|it, acc|
+            $acc | upsert ($sign.positional | get $it.index) $it.item
+        } )
+    if ($sign.rest | length) > 0 {
+        $opt._pos = ($opt._pos | upsert $sign.rest.0 $rest)
+    }
+    $opt
+}
+
+# def test [a b x? ...y --cd(-c) --ef(-e):string -g -h:int --ij --lm:bool] {}
+# (scope commands | where name == test).signatures?.0?.any?
+# get-sign test | to yaml
+# "test -h 111 123 'asdf' --cd --ef sadf -g -h 222" | cmd parse | to yaml