Merge pull request #22 from WebAssembly/text-format

Clarify the equivalence between the binary and text format

1 files changed, 8 insertions, 3 deletions

diff --git a/V1.md b/V1.md
index 2f9dc5e..c743ec1 100644
--- a/V1.md
+++ b/V1.md
@@ -14,7 +14,7 @@ precise descriptions of:
  * At the top level, a module is ELF-like: a squence of sections which declare their type and byte-length.
  * Sections with unknown types would be skipped without error. 
  * Standardized section types:
-  * module import section (see [Module imports](V1.md#module-imports) below)  
+  * module import section (see [Module imports](V1.md#module-imports) below)
   * globals section (constants, signatures, variables)
   * code section (see [Code section](V1.md#code-section) below)
   * heap initialization section (see [Heap](V1.md#heap) below)
@@ -45,7 +45,10 @@ precise descriptions of:
  * See the [AST Semantics](AstSemantics.md) for descriptions of individual AST nodes.
 
 ## Binary format
-* This is the format natively decoded by the browser.
+* The sole purpose of this format is efficiency: reducing download size and making decoding
+  faster, thus enabling even very large codebases to have quick startup times.
+  * Towards that goal, the binary format will be natively decoded by the browser.
+* The binary format has an equivalent and isomorphic [text format](V1.md#text-format).
 * Do not try to compete with a generic compression algorithm by trying to suck out every last bit;
   assume a generic compression algorithm is applied on top of the binary encoding.
 * "Given that text is so compressible and it is well known that it is hard to beat gzipped source,
@@ -63,10 +66,12 @@ precise descriptions of:
 
 ## Text format
 * The purpose of this format is to support:
-  * View Source on a WebAssembly module.
+  * View Source on a WebAssembly module, thus fitting into the Web (where every source can
+    be viewed) in a natural way.
   * Presentation in browser devtools when source maps aren't present (which is necessarily the case with v.1).
   * Writing WebAssembly code directly for reasons including pedagogical, experimental, debugging, or
     optimization.
+* The text format is equivalent and isomorphic to the [binary format](V1.md#binary-format).
 * Given that the code representation is actually an AST, the syntax would contain nested
   statements and expressions (instead of the linear list of instructions most assembly languages have).
 * There is no requirement to use JS syntax; this format is not intended to be evaluated or translated