[gnuastro-commits] master 86df9d8 25/62: Table: Completion, custom compgen

[Mohammad Akhlaghi]

branch: master
commit 86df9d899619ecaff3e524ee3f0bb6c834162ce8
Author: Pedram Ashofteh Ardakani <pedramardakani@pm.me>
Commit: Mohammad Akhlaghi <mohammad@akhlaghi.org>

    Table: Completion, custom compgen
    
    Until now, the completions used the built-in 'compgen' command. But
    'compgen' did not handle '-' inside a single suggestion such as
    'QUERY-CONFIG' for '--wcshdu' option. With this commit, the
    '_gnuastro_autocomplete_compgen' is introduced. The behavior is
    completely predictable.
    
    Also, the global variables are 'unset' when they are not needed.
    
    Lastly, the '=' sign is handled well in this version. It is removed if
    it is counted as the current word, and it is ignored if it was counted
    as the previous word. This way we have a way of knowing which long
    option is being completed. Furthermore, this prevents some complications
    while we are filtering out the suggestions.
---
 bin/table/completion.sh | 53 ++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 44 insertions(+), 9 deletions(-)

diff --git a/bin/table/completion.sh b/bin/table/completion.sh
index 814eba3..2ad7c81 100644
--- a/bin/table/completion.sh
+++ b/bin/table/completion.sh
@@ -54,12 +54,27 @@ _gnuastro_autocomplete_get_fits_hdu(){
     fi
 }
 
+_gnuastro_autocomplete_compgen(){
+    # Accept either an array or a string split by normal bash conventions,
+    # check if the current word being completed is present in the
+    # suggestions, if so, put it in suggestions, continue otherwise.
+    for w in $1
+    do
+        [[ "$w" =~ $word ]] && COMPREPLY+=( "$w" )
+    done
+}
+
 _gnuastro_autocomplete_list_fits_hdu(){
     # Checks for the current fits file and puts its headers into
     # completion suggestions
     if [ -f "$1"  ]; then
-        list=$(_gnuastro_autocomplete_get_fits_hdu "$1")
-        COMPREPLY=($(compgen -W "$list"))
+        list=("$(_gnuastro_autocomplete_get_fits_hdu $1)")
+        # A custom enhancement for the 'compgen' command. This version will
+        # have no problem with the dash sign '-'. Because sometimes the
+        # 'hdu' names might contain dash symbols in them. This ensures that
+        # all of them are suggested.
+        _gnuastro_autocomplete_compgen "${list[@]}"
+        unset list
     fi
 }
 
@@ -120,7 +135,8 @@ _gnuastro_autocomplete_list_fits_columns(){
     # its column names. If the file does not exist, pass.
     if [ -f "$1" ]; then
         list=$(_gnuastro_autocomplete_get_fits_columns "$1")
-        COMPREPLY=($(compgen -W "$list"))
+        COMPREPLY=($(compgen -W "${list[@]}"))
+        unset list
     fi
 }
 
@@ -139,8 +155,9 @@ _gnuastro_autocomplete_list_options(){
     # types. For example the 'asttable' program can either accept a fits
     # file or various short/long options as its first argument. In this
     # case, autocompletion suggests both.
-    list=$("$1" --help | awk -v regex=" --+[a-zA-Z0-9]*=?" 'match($0, regex) 
{print substr($0, RSTART, RLENGTH)}')
-    COMPREPLY+=($(compgen -W "$list" -- "$word"))
+    list=("$($1 --help | awk -v regex=' --+[a-zA-Z0-9]*=?' 'match($0, regex) 
{print substr($0, RSTART, RLENGTH)}')")
+    _gnuastro_autocomplete_compgen "${list[@]}"
+    unset list
 }
 
 _gnuastro_asttable_completions(){
@@ -153,11 +170,28 @@ _gnuastro_asttable_completions(){
     # Initialize the completion response with null
     COMPREPLY=();
 
-    # Variable "word", is the current word being completed
-    word="${COMP_WORDS[COMP_CWORD]}";
+    # Variable "word", is the current word being completed. "$2" is the
+    # default value for the current word in completion scripts. But we are
+    # using the longer form: "${COMP_WORDS[COMP_CWORD]}" for clarity.
+    word="${COMP_WORDS[COMP_CWORD]}"
+    if [ "$word" = "=" ]; then
+        # The equal sign '=' raises complexities when filling suggestions
+        # for long options. Things will work out fine when they are simply
+        # ignored.
+        word=""
+    fi
 
-    # Variable "prev" is the word just before the current word
-    prev="${COMP_WORDS[COMP_CWORD-1]}";
+    # Variable "prev", is one word before the one being completed. By
+    # default, this is set as "$3" in completion scripts. But we are using
+    # the longer form: "${COMP_WORDS[COMP_CWORD-1]}" for clarity.
+    prev="${COMP_WORDS[COMP_CWORD-1]}"
+    if [ "$prev" = "=" ]; then
+        # While a user is writing a long option's argument, the previous
+        # word will be the equal sign '='. This is not helpful at all. But
+        # looking at a word just before '=' helps us understand which long
+        # option is being called upon.
+        prev="${COMP_WORDS[COMP_CWORD-2]}"
+    fi
 
     # A quick check to see if there is already a fits file name invoked in
     # the current commandline. This means the order of commands does matter
@@ -214,6 +248,7 @@ _gnuastro_asttable_completions(){
 >>> prev: '$prev' -- \$3: '$3'
 >>> word: '$word' -- \$2: '$2'
 >>> fits_name: '$fits_name'
+>>> COMPREPLY: '${COMPREPLY[@]}'
 EOF
         printf ">>> line: %s" "$COMP_LINE"
     fi