From 407caee006a682b0d4981ee9832ab398d423dbde Mon Sep 17 00:00:00 2001
From: Erez <exb4096@rit.edu>
Date: Sun, 10 May 2020 15:52:40 -0400
Subject: [PATCH] Create oeis.sh

Allows integer sequences from [OEIS](https://oeis.org/) to be browsed, and to print syntax highlighted code samples for sequence implementation.
[Demo](https://github.com/ErezBinyamin/Scripts/blob/master/tools/img/oeis.gif)
[Source maintained here](https://github.com/ErezBinyamin/Scripts/blob/master/tools/oeis.sh)
---
 share/adapters/oeis.sh | 110 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 share/adapters/oeis.sh

diff --git a/share/adapters/oeis.sh b/share/adapters/oeis.sh
new file mode 100644
index 0000000..f2594eb
--- /dev/null
+++ b/share/adapters/oeis.sh
@@ -0,0 +1,110 @@
+#!/usr/bin/env bash
+
+# Written by Erez Binyamin (github.com/ErezBinyamin)
+
+# Search for an integer sequence
+oeis() {
+  local URL='https://oeis.org'
+  local TMP=/tmp/oeis
+  local DOC=/tmp/oeis/doc.html
+  mkdir -p $TMP
+  # Search sequence by ID
+  if [ $# -eq 1 ]
+  then
+    # Generate URL
+    [[ ${1:0:1} == 'A' ]] && ID=${1:1} || ID=${1}
+    ID=$(bc <<< "$ID")
+    ID="A$(printf '%06d' ${ID})"
+    URL+="/${ID}"
+    curl $URL 2>/dev/null > $DOC
+    # ID
+    printf "ID: ${ID}\n"
+    # Description
+    grep -A 1 '<td valign=top align=left>' $DOC \
+      | sed '/<td valign=top align=left>/d; /--/d; s/^[ \t]*//; s/<[^>]*>//g;' \
+      | sed 's/&nbsp;/ /g; s/\&amp;/\&/g; s/&gt;/>/g; s/&lt;/</g; s/&quot;/"/g'
+    printf "\n"
+    # Sequence
+    grep -o '<tt>.*, .*[0-9]</tt>' $DOC \
+      | sed 's/<[^>]*>//g' \
+      | grep -v '[a-z]' \
+      | grep -v ':'
+    printf "\n"
+    # Code
+    if grep -q 'MAPLE' $DOC
+    then
+        GREP_REGEX='MAPLE.*CROSSREFS'
+        grep -q 'PROG' $DOC && GREP_REGEX='MAPLE.*PROG'
+        grep -q 'MATHEMATICA' $DOC && GREP_REGEX='MAPLE.*MATHEMATICA'
+        cat $DOC \
+          | tr '\n' '`' \
+          | grep -o "${GREP_REGEX}" \
+          | tr '`' '\n' \
+          | sed 's/^[ \t]*//; s/<[^>]*>//g; /^\s*$/d;' \
+          | sed 's/&nbsp;/ /g; s/\&amp;/\&/g; s/&gt;/>/g; s/&lt;/</g; s/&quot;/"/g' \
+          | sed 's/MAPLE/(MAPLE)/; /MATHEMATICA/d; /PROG/d; /CROSSREFS/d' \
+          | pygmentize -f terminal256 -g -l python -P style=monokai
+        printf "\n"
+    fi
+    if grep -q 'MATHEMATICA' $DOC
+    then
+        GREP_REGEX='MATHEMATICA.*CROSSREFS'
+        grep -q 'PROG' $DOC && GREP_REGEX='MATHEMATICA.*PROG'
+        cat $DOC \
+          | tr '\n' '`' \
+          | grep -o "${GREP_REGEX}" \
+          | tr '`' '\n' \
+          | sed 's/^[ \t]*//; s/<[^>]*>//g; /^\s*$/d;' \
+          | sed 's/&nbsp;/ /g; s/\&amp;/\&/g; s/&gt;/>/g; s/&lt;/</g; s/&quot;/"/g' \
+          | sed 's/MATHEMATICA/(MATHEMATICA)/; /PROG/d; /CROSSREFS/d' \
+          | pygmentize -f terminal256 -g -l mathematica -P style=monokai
+        printf "\n"
+    fi
+    # PROG section language support
+    cat $DOC \
+      | tr '\n' '`' \
+      | grep -o "PROG.*CROSSREFS" \
+      | tr '`' '\n' \
+      | sed 's/^[ \t]*//; s/<[^>]*>//g; /^\s*$/d;' \
+      | sed 's/&nbsp;/ /g; s/\&amp;/\&/g; s/&gt;/>/g; s/&lt;/</g; s/&quot;/"/g' \
+      | sed '/PROG/d; /CROSSREFS/d' > ${TMP}/lang
+    langs=("Axiom" "MAGMA" "PARI" "Python" "Sage" "Haskell" "Julia" "GAP" "Scala")
+    for L in ${langs[@]}
+    do
+        echo "foo" | pygmentize -l ${L,,} &>/dev/null && PYG="${L,,}" || PYG="c"
+        if grep -q "(${L})" $DOC
+        then
+              awk -v tgt="${L}" -F'[()]' '/^\(/{f=(tgt==$2)} f' ${TMP}/lang \
+              | pygmentize -f terminal256 -g -P style=monokai -l ${PYG}
+              printf "\n"
+        fi
+    done
+  # Search unknown sequence
+  else
+    # Build URL
+    URL+="/search?q=signed%3A$(echo $@ | tr ' ' ',')"
+    curl $URL 2>/dev/null > $DOC
+    # Sequence IDs
+    grep -o '=id:.*&' $DOC \
+      | sed 's/=id://; s/&//' > $TMP/id
+    # Descriptions
+    grep -A 1 '<td valign=top align=left>' $DOC \
+      | sed '/<td valign=top align=left>/d; /--/d; s/^[ \t]*//; s/<[^>]*>//g' \
+      | sed 's/&nbsp;/ /g; s/\&amp;/\&/g; s/&gt;/>/g; s/&lt;/</g; s/&quot;/"/g' > $TMP/nam
+    # Sequences
+    grep -o '<tt>.*<b.*</tt>' $DOC \
+      | sed 's/<[^>]*>//g' > $TMP/seq
+    # Print data for all
+    readarray -t ID < $TMP/id
+    readarray -t NAM < $TMP/nam
+    readarray -t SEQ < $TMP/seq
+    for i in ${!ID[@]}
+    do
+      printf "${ID[$i]}: ${NAM[$i]}\n"
+      echo ${SEQ[$i]}
+      printf "\n"
+    done
+  fi
+}
+
+oeis $@