feat(comps): improve bash completion script word tracking

Rework bash completion script to fix word-index tracking when the
cursor is in the middle of a word, compute the current word from
COMP_LINE truncated at COMP_POINT, and use space-separated option
arguments. Also trim colon prefixes from completion items when
COMP_WORDBREAKS includes colons.

2 files changed, 33 insertions, 12 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 69bfe43..590d566 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -59,6 +59,8 @@ None
 
 1. **[`comps:zsh`]** Fixed zsh completion script to properly escape colons in completion descriptions. The zsh completion script generated for the `zsh` output format now escapes colon characters in completion items (`${item//:/\\:}`) and description parts (`${match[1]//:/\\:}`) so that descriptions containing colons don't break the `_describe` command's parsing. Additionally, fixed the simple-completions branch to iterate over the original `completions` array (with the colon-escaped format matching) rather than the already-parsed `parsed_completions` array, correctly extracting the completion item when no description is present.
 
+2. **[`comps:bash`]** Reworked the bash completion script template to fix word-index tracking when the cursor is in the middle of a word and to add colon-ltrimming for completion descriptions. The script now computes the current word (`cur`) using `COMP_LINE` truncated to `COMP_POINT` (taking the last whitespace-delimited token) rather than relying on `COMP_WORDS[COMP_CWORD]`, which fails when the cursor is in the middle of a word. The word index is derived from the count of words preceding the current cursor position (`before_words`), and `prev` is the last word in that preceding set. The option flags to the underlying completion engine are now passed as `-f value`/`-C value`/etc. (space-separated) instead of `-f=value`/`-C=value`/etc. (equals-separated), since the engine expects space-delimited argument pairs. Additionally, when the current word contains a colon and `COMP_WORDBREAKS` includes `:`, the completion items are trimmed of the colon prefix before being inserted into `COMPREPLY` — this prevents completions like `foo:bar` from being double-prefixed with the literal `foo:bar` when bash would otherwise append the full word.
+
 #### Optimizations:
 
 1. **[`pathf`]** Added `is_module` field to `AnalyzeItem` and a new constructor `AnalyzeItem::local_module(module, item_name)` which sets `is_module: true`. The `type_mapping_builder` now tracks whether an item is a module: when generating `type_using.rs`, module items produce `use path::to::module::*;` (glob import) instead of the standard `use path::to::TypeName;` direct import. Non-module items continue to use direct imports as before. The internal data structure changed from `Vec<(String, String)>` to `Vec<(String, String, bool)>` to carry the `is_module` flag through the pipeline.
diff --git a/mingling_core/tmpls/comps/bash.sh b/mingling_core/tmpls/comps/bash.sh
index 1af4f6c..edec28d 100644
--- a/mingling_core/tmpls/comps/bash.sh
+++ b/mingling_core/tmpls/comps/bash.sh
@@ -1,22 +1,31 @@
 #!/usr/bin/env bash
 _<<<bin_name>>>_bash_completion() {
-    local cur="${COMP_WORDS[COMP_CWORD]}"
+    local line="${COMP_LINE:0:COMP_POINT}"
+    local cur="${line##* }"
     local prev=""
-    [ $COMP_CWORD -gt 0 ] && prev="${COMP_WORDS[COMP_CWORD-1]}"
+    local word_index=1
 
-    local word_index=$((COMP_CWORD + 1))
+    local before="${line:0:$(( ${#line} - ${#cur} ))}"
+    local -a before_words
+    if [[ -n "$before" ]]; then
+        read -ra before_words <<< "$before"
+        word_index=$(( ${#before_words[@]} + 1 ))
+        if [[ $word_index -gt 1 ]]; then
+            prev="${before_words[${#before_words[@]}-1]}"
+        fi
+    fi
 
     local args=()
-    args+=(-f="${COMP_LINE//-/^}")
-    args+=(-C="$COMP_POINT")
-    args+=(-w="${cur//-/^}")
-    args+=(-p="${prev//-/^}")
-    args+=(-c="${COMP_WORDS[0]//-/^}")
-    args+=(-i="$word_index")
-    args+=(-F="bash")
+    args+=(-f "${COMP_LINE//-/^}")
+    args+=(-C "$COMP_POINT")
+    args+=(-w "${cur//-/^}")
+    args+=(-p "${prev//-/^}")
+    args+=(-c "${COMP_WORDS[0]//-/^}")
+    args+=(-i "$word_index")
+    args+=(-F "bash")
 
     for word in "${COMP_WORDS[@]}"; do
-        args+=(-a="${word//-/^}")
+        args+=(-a "${word//-/^}")
     done
 
     local suggestions
@@ -36,7 +45,17 @@ _<<<bin_name>>>_bash_completion() {
                     [ -z "$cur" ] || [[ "$suggestion" == "$cur"* ]] && filtered+=("$suggestion")
                 done
 
-                [ ${#filtered[@]} -gt 0 ] && COMPREPLY=("${filtered[@]}")
+                if [ ${#filtered[@]} -gt 0 ]; then
+                    COMPREPLY=("${filtered[@]}")
+                    if [[ "$cur" == *:* && "$COMP_WORDBREAKS" == *:* ]]; then
+                        local colon_prefix="${cur%"${cur##*:}"}"
+                        local -a ltrimmed=()
+                        for suggestion in "${COMPREPLY[@]}"; do
+                            ltrimmed+=("${suggestion#"$colon_prefix"}")
+                        done
+                        COMPREPLY=("${ltrimmed[@]}")
+                    fi
+                fi
                 return
             fi
         fi