chore: separating fishtool from main fish config

functions/fishtools.fish

@@ -0,0 +1,62 @@
+function fishtools-startswith
+    set len1 (string length $argv[1])
+    set len2 (string length $argv[2])
+    if test $len1 -lt $len2
+        set tmp (string sub -l $len1 $argv[2])
+        if test $tmp = $argv[1]
+            return 0
+        end
+    else
+        set tmp (string sub -l $len2 $argv[1])
+        if test $tmp = $argv[2]
+            return 0
+        end
+    end
+    return 1
+end
+
+function fishtools-in-list
+    if test (count $argv) -ge 2
+        for i in $argv[2..-1]
+            if test "$i" = "$argv[1]"
+                return 0
+            end
+        end
+    end
+    return 1
+end
+
+function fishtools-enable-rust
+    if test -e $HOME/.cargo/bin
+        set real (realpath $HOME/.cargo/bin)
+
+        if not fishtools in $real $PATH
+            set -gx PATH $real $PATH
+        end
+    end
+end
+
+function fishtools-enable
+    for i in $argv
+        switch $i
+            case rust
+                fishtools-enable-rust
+            case '*'
+                echo "unsupported " $argv[1]
+        end
+    end
+end
+
+function fishtools
+    switch $argv[1]
+        case startswith
+            fishtools-startswith $argv[2..-1]
+        case in
+            fishtools-in-list $argv[2..-1]
+        case enable
+            fishtools-enable $argv[2..-1]
+        case '*'
+            echo "unknown sub-command:" $argv
+            return 1
+    end
+end