Add streaming utilities (fix #827)

tests/modules/streaming.jq

@@ -1,49 +0,0 @@
-
-# Filter and adjust streamed values so that only values from the .th
-# level are output.
-def trunc(stream):
-  . as $n | stream | . as $input | if (.[0]|length) > $n then setpath([0];$input[0][$n:]) else empty end;
-
-# Reduce streamed values back to normal
-def tovalues(i):
-  def debug(msg): . as $dot | [msg, .] | debug | $dot;
-  foreach i as $item (
-    [null,false,null];
-
-    # Updator
-    # 
-    # If the new $item is a top-level value,
-    # then clear out the current value
-    .                   as [$cur, $cur_isvalid, $prev]  |
-    $item               as [$path, $leaf]               |
-    ($item|length > 1)  as $has_leaf                    |
-    ($item|length == 1) as $closing                     |
-    ($path|length)      as $plen                        |
-    # if the new $item terminates the current value, then cur is ready
-    # for extraction and we'll start building a new value with the next
-    # inputs
-    if ($plen == 0) or # top-level scalar
-       ($closing and $plen < 2) then [null,false,$cur]
-    # else continue building up cur
-    else . end                                          |
-    . as [$cur, $cur_isvalid, $prev]                    |
-    # If the new $item has a leaf, upate the current value
-    if $has_leaf and $plen > 0 then
-      [$cur|setpath(($path); $leaf),              # update current value
-      true,                                         # current value is now valid (if, perhaps, incomplete)
-      $prev]                                        # previous value is unchanged
-    else .
-    end;
-
-    # Extractor
-    #
-    . as [$cur, $cur_isvalid, $prev]                    |
-    $item as [$path, $leaf]                             |
-    ($item|length > 1) as $has_leaf                     |
-    ($item|length == 1) as $closing                     |
-    ($path|length) as $plen                             |
-    # If previous value is valid, output it
-    if $plen == 1 and $closing then $prev else empty end,
-    # and/or if the new $item is a top-level scalar, output it
-    if $plen == 0 then $leaf else empty end
-    );

tests/shtest

@@ -77,9 +77,6 @@ fi
 
 ## Test JSON sequence support
 
-## XXX If we add a `stream_fromjson` builtin then we can move these tests
-## into tests/all.test
-
 cat > $d/expected <<EOF
 ignoring parse error: Truncated value at line 2, column 5
 ignoring parse error: Truncated value at line 2, column 25
@@ -149,7 +146,7 @@ if which seq > /dev/null 2>&1; then
         fi
 
         dd "if=tests/torture/input0.json" bs=$i count=1 2>/dev/null |
-            $VALGRIND $JQ -cn --stream -L "$mods" 'import "streaming" as streaming; streaming::tovalues(inputs)' > $d/out1 2>$d/err || true
+            $VALGRIND $JQ -cn --stream 'fromstream(inputs)' > $d/out1 2>$d/err || true
         if [ -n "$VALGRIND" ]; then
             grep '^==[0-9][0-9]*== ERROR SUMMARY: 0 errors' $d/err > /dev/null
         else