json-rpc-shell/json-format.pl

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3.7 KiB
Perl
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#!/usr/bin/env perl
use strict;
use warnings;
use Term::ANSIColor;
use Getopt::Long;
my $reset = color('reset');
my %format = (
FIELD => color('bold'),
NULL => color('cyan'),
BOOL => color('red'),
NUMBER => color('magenta'),
STRING => color('blue'),
ERROR => color('bold white on_red'),
);
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my ($color, $keep_ws, $help) = 'auto';
if (!GetOptions('color=s' => \$color, 'keep-ws' => \$keep_ws, 'help' => \$help)
|| $help) {
print STDERR
"Usage: $0 [OPTION...] [FILE...]\n" .
"Pretty-print and colorify JSON\n" .
"\n" .
" --help print this help\n" .
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" --keep-ws retain all original whitespace\n" .
" --color=COLOR 'always', 'never' or 'auto' (the default)\n";
exit 2;
}
%format = ()
if $color eq 'never' || $color eq 'auto' && !-t STDOUT;
# Hash lookup is the fastest way to qualify tokens, however it cannot be used
# for everything and we need to fall back to regular expressions
my %lookup = (
'[' => 'LBRACKET', '{' => 'LBRACE',
']' => 'RBRACKET', '}' => 'RBRACE',
':' => 'COLON', ',' => 'COMMA',
'true' => 'BOOL', 'false' => 'BOOL', 'null' => 'NULL',
);
my @pats = (
['"(?:[^\\\\"]*|\\\\(?:u[\da-f]{4}|["\\\\/bfnrt]))*"' => 'STRING'],
['-?\d+(?:\.\d+)?(?:[eE][-+]?\d+)?' => 'NUMBER'],
['[ \t\r\n]+' => 'WS'],
);
my @tokens = map {[qr/^$_->[0]$/s, $_->[1]]} @pats;
# m//g is the fastest way to explode text into tokens in the first place
# and we need to construct an all-encompassing regular expression for it
my @all_pats = map {$_->[0]} @pats;
push @all_pats, quotemeta for keys %lookup;
my $any_token = qr/\G(${\join '|', @all_pats})/;
# FIXME: this probably shouldn't be a global variable
my $indent = 0;
sub nexttoken ($) {
my $json = shift;
if (!@$json) {
return unless defined (my $line = <>);
push @$json, $line =~ /$any_token/gsc;
push @$json, substr $line, pos $line
if pos $line != length $line;
}
my $text = shift @$json;
if (my $s = $lookup{$text}) {
return $s, $text;
}
for my $s (@tokens) {
return $s->[1], $text if $text =~ $s->[0];
}
return 'ERROR', $text;
}
sub gettoken ($) {
my $json = shift;
while (my ($token, $text) = nexttoken $json) {
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next if !$keep_ws && $token eq 'WS';
return $token, $text;
}
return;
}
sub printindent () {
print "\n", ' ' x $indent;
}
sub do_value ($$$);
sub do_object ($) {
my $json = shift;
my $in_field_name = 1;
my $first = 1;
while (my ($token, $text) = gettoken $json) {
if ($token eq 'COLON') {
$in_field_name = 0;
} elsif ($token eq 'COMMA') {
$in_field_name = 1;
} elsif ($token eq 'STRING') {
$token = 'FIELD' if $in_field_name;
}
if ($token eq 'RBRACE') {
$indent--;
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printindent unless $keep_ws;
} elsif ($first) {
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printindent unless $keep_ws;
$first = 0;
}
do_value $token, $text, $json;
return if $token eq 'RBRACE';
}
}
sub do_array ($) {
my $json = shift;
my $first = 1;
while (my ($token, $text) = gettoken $json) {
if ($token eq 'RBRACKET') {
$indent--;
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printindent unless $keep_ws;
} elsif ($first) {
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printindent unless $keep_ws;
$first = 0;
}
do_value $token, $text, $json;
return if $token eq 'RBRACKET';
}
}
sub do_value ($$$) {
my ($token, $text, $json) = @_;
if (my $format = $format{$token}) {
print $format, $text, $reset;
} else {
print $text;
}
if ($token eq 'LBRACE') {
$indent++;
do_object $json;
} elsif ($token eq 'LBRACKET') {
$indent++;
do_array $json;
} elsif ($token eq 'COMMA') {
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printindent unless $keep_ws;
} elsif ($token eq 'COLON') {
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print ' ' unless $keep_ws;
}
}
my @buffer;
while (my ($token, $text) = gettoken \@buffer) {
do_value $token, $text, \@buffer;
print "\n" unless $keep_ws;
}