[feature] Added support for negative alt condition

test/test_unit_score_file.py

@@ -321,3 +321,74 @@ def test_underscores_and_upper_case_in_distro_and_family(runner, yadm):
     assert run.success
     assert run.err == ""
     assert run.out == expected
+
+def test_negative_class_condition(runner, yadm):
+    """Test negative class condition: returns 0 when matching and proper score when not matching."""
+    script = f"""
+        YADM_TEST=1 source {yadm}
+        local_class="testclass"
+        local_classes=("testclass")
+
+        # 0
+        score=0
+        score_file "filename##~class.testclass" "dest"
+        echo "score: $score"
+
+        # 16
+        score=0
+        score_file "filename##~class.badclass" "dest"
+        echo "score2: $score"
+
+        # 16
+        score=0
+        score_file "filename##~c.badclass" "dest"
+        echo "score3: $score"
+    """
+    run = runner(command=["bash"], inp=script)
+    assert run.success
+    output = run.out.strip().splitlines()
+    assert output[0] == "score: 0"
+    assert output[1] == "score2: 16"
+    assert output[2] == "score3: 16"
+
+def test_negative_combined_conditions(runner, yadm):
+    """Test negative conditions for multiple alt types: returns 0 when matching and proper score when not matching."""
+    script = f"""
+        YADM_TEST=1 source {yadm}
+        local_class="testclass"
+        local_classes=("testclass")
+        local_distro="testdistro"
+
+        # (0) + (0) = 0
+        score=0
+        score_file "filename##~class.testclass,~distro.testdistro" "dest"
+        echo "score: $score"
+
+        # (1000 + 16) + (1000 + 4) = 2020
+        score=0
+        score_file "filename##class.testclass,distro.testdistro" "dest"
+        echo "score2: $score"
+
+        # 0 (negated class condition)
+        score=0
+        score_file "filename##~class.badclass,~distro.testdistro" "dest"
+        echo "score3: $score"
+
+        # (1000 + 16) + (4) = 1020
+        score=0
+        score_file "filename##class.testclass,~distro.baddistro" "dest"
+        echo "score4: $score"
+
+        # (1000 + 16) + (16) = 1032
+        score=0
+        score_file "filename##class.testclass,~class.badclass" "dest"
+        echo "score5: $score"
+    """
+    run = runner(command=["bash"], inp=script)
+    assert run.success
+    output = run.out.strip().splitlines()
+    assert output[0] == "score: 0"
+    assert output[1] == "score2: 2020"
+    assert output[2] == "score3: 0"
+    assert output[3] == "score4: 1020"
+    assert output[4] == "score5: 1032"

yadm

@@ -179,32 +179,39 @@ function score_file() {
     local value=${field#*.}
     [ "$field" = "$label" ] && value="" # when .value is omitted
 
+    # Check for negative condition prefix (e.g., "~<label>")
+    local negate=0
+    if [ "${label:0:1}" = "~" ]; then
+      negate=1
+      label="${label:1}"
+    fi
+
     shopt -s nocasematch
-    local -i delta=-1
+    local -i delta=$(( negate ? 1 : -1 ))
     case "$label" in
       default)
         delta=0
         ;;
       a | arch)
-        [[ "$value" = "$local_arch" ]] && delta=1
+        [[ "$value" = "$local_arch" ]] && delta=1 || delta=-1
         ;;
       o | os)
-        [[ "$value" = "$local_system" ]] && delta=2
+        [[ "$value" = "$local_system" ]] && delta=2 || delta=-2
         ;;
       d | distro)
-        [[ "${value// /_}" = "${local_distro// /_}" ]] && delta=4
+        [[ "${value// /_}" = "${local_distro// /_}" ]] && delta=4 || delta=-4
         ;;
       f | distro_family)
-        [[ "${value// /_}" = "${local_distro_family// /_}" ]] && delta=8
+        [[ "${value// /_}" = "${local_distro_family// /_}" ]] && delta=8 || delta=-8
         ;;
       c | class)
-        in_list "$value" "${local_classes[@]}" && delta=16
+        in_list "$value" "${local_classes[@]}" && delta=16 || delta=-16
         ;;
       h | hostname)
-        [[ "$value" = "$local_host" ]] && delta=32
+        [[ "$value" = "$local_host" ]] && delta=32 || delta=-32
         ;;
       u | user)
-        [[ "$value" = "$local_user" ]] && delta=64
+        [[ "$value" = "$local_user" ]] && delta=64 || delta=-64
         ;;
       e | extension)
         # extension isn't a condition and doesn't affect the score
@@ -230,11 +237,13 @@ function score_file() {
     esac
     shopt -u nocasematch
 
+    (( negate )) && delta=$((-delta))
     if ((delta < 0)); then
       score=0
       return
     fi
-    score=$((score + 1000 + delta))
+    (( negate )) || delta=$((delta + 1000))
+    score=$((score + delta))
   done
 
   record_score "$score" "$target" "$source" "$template_processor"

yadm.1

@@ -489,7 +489,7 @@ These are the supported attributes, in the order of the weighted precedence:
 Valid when the value matches a supported template processor.
 See the TEMPLATES section for more details.
 .TP
-.BR user ,\  u
+.BR user ,\  u\ 
 Valid if the value matches the current user.
 Current user is calculated by running
 .BR "id \-u \-n" .
@@ -575,6 +575,7 @@ files are managed by yadm's repository:
   - $HOME/path/example.txt##os.Linux
   - $HOME/path/example.txt##os.Linux,hostname.host1
   - $HOME/path/example.txt##os.Linux,hostname.host2
+  - $HOME/path/example.txt##~os.Linux,~os.Darwin,~os.SunOS
 
 If running on a Macbook named "host2",
 yadm will create a symbolic link which looks like this:
@@ -601,6 +602,13 @@ If running on a system, with class set to "Work", the link will be:
 
 .IR $HOME/path/example.txt " -> " $HOME/path/example.txt##class.Work
 
+Negative conditions are supported via the "~" prefix. If running within 
+Windows Subsystem for Linux, where the os is reported as WSL, the link will be:
+
+.IR $HOME/path/example.txt " -> " $HOME/path/example.txt##~os.Linux,~os.Darwin,~os.SunOS
+
+Negative conditions use the same weight which corresponds to the attached attribute.
+
 If no "##default" version exists and no files have valid conditions, then no
 link will be created.