From e792598c698439f5cde48a996cefc3738e58ec56 Mon Sep 17 00:00:00 2001
From: Mattias Wadman <mattias.wadman@gmail.com>
Date: Mon, 24 Jan 2022 18:21:43 +0100
Subject: [PATCH] interp: Add grep_by/1 to recursively match using a filter

Refactor other grep functions to use it
---
 doc/usage.md                    |  1 +
 pkg/interp/grep.jq              | 61 +++++++++++----------------------
 pkg/interp/testdata/grep.fqtest | 18 ++++++++++
 3 files changed, 39 insertions(+), 41 deletions(-)

diff --git a/doc/usage.md b/doc/usage.md
index c134a904..a89b8964 100644
--- a/doc/usage.md
+++ b/doc/usage.md
@@ -318,6 +318,7 @@ unary uses input and if more than one argument all as arguments ignoring the inp
     - `vgrep/1`, `vgrep/2` recursively match value
     - `bgrep/1`, `bgrep/2` recursively match buffer
     - `fgrep/1`, `fgrep/2` recursively match field name
+  - `grep_by/1` recursively match using a filter. Ex: `grep_by(. > 180 and . < 200)`, `first(grep_by(format == "id3v2"))`.
   - Buffers:
     - `tobits/0` - Transform input into a bits buffer not preserving source range, will start at zero.
     - `tobitsrange/0` - Transform input into a bits buffer preserving source range if possible.
diff --git a/pkg/interp/grep.jq b/pkg/interp/grep.jq
index 182dbfc5..58da6722 100644
--- a/pkg/interp/grep.jq
+++ b/pkg/interp/grep.jq
@@ -1,13 +1,7 @@
-def _grep($v; filter_cond; string_cond; other_cond):
-  if $v | type == "string" then
-    ( ..
-    | select(filter_cond and string_cond)
-    )
-  else
-    ( ..
-    | select(filter_cond and other_cond)
-    )
-  end;
+def grep_by(f):
+  ( ..
+  | select(f)?
+  );
 
 def _value_grep_string_cond($v; $flags):
   if type == "string" then test($v; $flags)
@@ -18,46 +12,31 @@ def _value_grep_other_cond($v; $flags):
   . == $v;
 
 def vgrep($v; $flags):
-  _grep(
-    $v;
-    _is_scalar;
-    _value_grep_string_cond($v; $flags);
-    _value_grep_other_cond($v; $flags)
-  );
-
+  if $v | type == "string" then
+    grep_by(_is_scalar and _value_grep_string_cond($v; $flags))
+  else
+    grep_by(_is_scalar and _value_grep_other_cond($v; $flags))
+  end;
 def vgrep($v): vgrep($v; "");
 
 def _buf_grep_any_cond($v; $flags):
   (isempty(tobytesrange | match($v; $flags)) | not)? // false;
 def bgrep($v; $flags):
-  _grep(
-    $v;
-    _is_scalar;
-    _buf_grep_any_cond($v; $flags);
-    _buf_grep_any_cond($v; $flags)
-  );
-
+  if $v | type == "string" then
+    grep_by(_is_scalar and _buf_grep_any_cond($v; $flags))
+  else
+    grep_by(_is_scalar and _buf_grep_any_cond($v; $flags))
+  end;
 def bgrep($v): bgrep($v; "");
 
 def grep($v; $flags):
-  _grep(
-    $v;
-    _is_scalar;
-    _buf_grep_any_cond($v; $flags) or _value_grep_string_cond($v; $flags);
-    _buf_grep_any_cond($v; $flags) or _value_grep_other_cond($v; $flags)
-  );
-
+  if $v | type == "string" then
+    grep_by(_is_scalar and _buf_grep_any_cond($v; $flags) or _value_grep_string_cond($v; $flags))
+  else
+    grep_by(_is_scalar and _buf_grep_any_cond($v; $flags) or _value_grep_other_cond($v; $flags))
+  end;
 def grep($v): grep($v; "");
 
-def _field_grep_string_cond($v; $flags):
-  (._name | test($v; $flags))? // false;
-
 def fgrep($v; $flags):
-  _grep(
-    $v;
-    _is_decode_value;
-    _field_grep_string_cond($v; $flags);
-    empty
-  );
-
+  grep_by(_is_decode_value and (._name | test($v; $flags))? // false);
 def fgrep($v): fgrep($v; "");
diff --git a/pkg/interp/testdata/grep.fqtest b/pkg/interp/testdata/grep.fqtest
index 6921137b..712c6d3d 100644
--- a/pkg/interp/testdata/grep.fqtest
+++ b/pkg/interp/testdata/grep.fqtest
@@ -56,4 +56,22 @@ mp3> bgrep(44100, "ID", "^ID3$", "^ID.?$", "Info", "magic", "\u00ff", [0x49, 0x4
 mp3> "64ff65ff66" | hex | bgrep("\u00ff"; "b")
    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|
 0x0|64 ff 65 ff 66|                                |d.e.f|          |.: raw bits 0x0-0x4.7 (5)
+mp3> grep_by(. == 44100)
+    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|
+0x20|                                             40|               @|.frames[0].header.sample_rate: 44100 (0)
+    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|
+0xe0|               50                              |     P          |.frames[1].header.sample_rate: 44100 (0)
+     |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|
+0x1b0|               52                              |     R          |.frames[2].header.sample_rate: 44100 (0)
+mp3> grep_by(format == "id3v2")
+    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|.headers[0]{}: (id3v2)
+0x00|49 44 33                                       |ID3             |  magic: "ID3" (valid)
+0x00|         04                                    |   .            |  version: 4
+0x00|            00                                 |    .           |  revision: 0
+0x00|               00                              |     .          |  flags{}:
+0x00|                  00 00 00 23                  |      ...#      |  size: 35
+0x00|                              54 53 53 45 00 00|          TSSE..|  frames[0:1]:
+0x10|00 0f 00 00 03 4c 61 76 66 35 38 2e 34 35 2e 31|.....Lavf58.45.1|
+0x20|30 30 00                                       |00.             |
+0x20|         00 00 00 00 00 00 00 00 00 00         |   ..........   |  padding: raw bits (all zero)
 mp3> ^D