Differences

This shows you the differences between two versions of the page.

--- language:langs:dflow [2023/04/09 23:46] – [Clusters and Ordering] rajit
+++ language:langs:dflow [2024/07/22 17:54] (current) – [Function] rajit
@@ Line 26: / Line 26: @@
 ===== Function =====
-The syntax shown above corresponds to the //function// dataflow block. A function dataflow element receives one input token on each of its input channels, computes a function of the values received, and produces one output token with the value computed. The example above shows the function syntax. The left hand side of the arrow is a channel expression that corresponds to the function being computed, and the right hand side is the name of the channel on which the output is produced.
+The syntax shown in the first example above corresponds to the //function// dataflow block. A function dataflow element receives one input token on each of its input channels, computes a function of the values received, and produces one output token with the value computed. The example above shows the function syntax. The left hand side of the arrow is a channel expression that corresponds to the function being computed, and the right hand side is the name of the channel on which the output is produced.
 ===== Split =====
@@ Line 57: / Line 57: @@
 <code act>
 dataflow {
-  {c = 0 ? 1 : 0} A -> X, Y
+  {c = 0 ? 0 : 1} A -> X, Y
 }
 </code>
@@ Line 64: / Line 64: @@
 <code  act>
 dataflow {
- c = 0 ? 1 : 0 -> ctrl;
+ c = 0 ? 0 : 1 -> ctrl;
 {ctrl} A -> X, Y
 }
@@ Line 92: / Line 92: @@
 }
 </code>
-The fact that ''a'' is used twice on the left hand side implies that there will be a token copy circuit introduced. Note also that semicolon is used as a separator, like in the CHP language.
+The fact that ''a'' is used twice on the left hand side implies that there will be a token copy circuit introduced. Note also that semicolon is used as a separator, so there is no semicolon after the last dataflow statement in the block.
 In pipelined circuits, it is important to be able to introduce slack to optimize performance. The syntax for this is the following:
@@ Line 213: / Line 213: @@
 dataflow {
   order {
-     c < e
+     c < e    // c must be produced before e is available
    }
    a + b -> c;
    d + e -> out
+ }
+</code>
+In general, the order block contains a semi-colon separated list of directives. Each directive is a list of comma-separated channels followed by ''<'' followed by a second comma-separated list of channels. The directive means that all the channels in the first group must produce outputs before any of the channels in the second group can receive inputs.
+====== Syntactic replication ======
+The dataflow sub-language has support for syntactic replication for splits, merges, mixers, and arbiters. For a split, the output side can use syntactic replication; for the others, the input side can use syntactic replication.
+For example, the following syntax is legal (assuming everything is of the right type):
+<code act>
+dataflow {
+  {ctrl} l -> (, i : 8 : out[i])
+ }
+</code>