Remove ethdebug/format/pointer/templates

... and just define ethdebug/format/pointer/template instead

packages/pointers/src/pointer.test.ts

@@ -178,9 +178,9 @@ describe("type guards", () => {
     },
     {
       schema: {
-        id: "schema:ethdebug/format/pointer/templates"
+        id: "schema:ethdebug/format/pointer/template"
       },
-      guard: Pointer.isTemplates
+      guard: Pointer.isTemplate
     },
   ] as const;
 

packages/pointers/src/test-cases.ts

@@ -1,7 +1,6 @@
 import {
   singleSourceCompilation,
   findExamplePointer,
-  findExampleTemplates,
   type ObserveTraceOptions
 } from "../test/index.js";
 import { type Cursor, Data } from "./index.js";
@@ -81,8 +80,7 @@ const structStorageTest: ObserveTraceTest<{
 };
 
 const stringStorageTest: ObserveTraceTest<string> = {
-  pointer: findExamplePointer("solidity-string-storage"),
-  templates: findExampleTemplates(),
+  pointer: findExamplePointer("string-storage-contract-variable-slot"),
 
   compileOptions: singleSourceCompilation({
     path: "StringStorage.sol",

packages/pointers/test/examples.ts

@@ -16,15 +16,3 @@ export const findExamplePointer = (() => {
     examplePointers
       .find(pointer => JSON.stringify(pointer).includes(text))!;
 })();
-
-export const findExampleTemplates = (() => {
-  const {
-    schema: {
-      examples: [exampleTemplates]
-    }
-  } = describeSchema({
-    schema: { id: "schema:ethdebug/format/pointer/templates" }
-  }) as { schema: { examples: Pointer.Templates[] } };
-
-  return (): Pointer.Templates => exampleTemplates;
-})();

packages/pointers/test/index.ts

@@ -11,7 +11,7 @@ export {
 
 export { deployContract, } from "./deploy.js";
 
-export { findExamplePointer, findExampleTemplates } from "./examples.js";
+export { findExamplePointer } from "./examples.js";
 
 export {
   observeTrace,

packages/web/spec/pointer/templates.mdx

@@ -6,28 +6,13 @@ import SchemaViewer from "@site/src/components/SchemaViewer";
 
 # Pointer templates
 
-This format provides the concept of **pointer templates** to allow
+This format provides the concept of a **pointer template** to allow
 deduplicating representations. Pointer templates are defined to specify the
 variables they expect in scope and the pointer definition that uses those
 variables.
 
-## Template schema {#template-schema}
-
-The following schema defines how to represent a single pointer template.
-See [below](#templates-schema) for how to organize pointer templates by name.
-
 <SchemaViewer
   schema={{
-    id: "schema:ethdebug/format/pointer/templates"
+    id: "schema:ethdebug/format/pointer/template"
   }}
-  pointer="#/$defs/Template"
-  />
-
-## Organizing templates {#templates-schema}
-
-The **ethdebug/format/pointer/templates** schema specifies how to represent
-a collection of pointer templates by name.
-
-<SchemaViewer
-  schema={{ id: "schema:ethdebug/format/pointer/templates" }}
   />

packages/web/src/schemas.ts

@@ -116,13 +116,8 @@ export const schemaIndex: SchemaIndex = {
     href: "/spec/pointer/expression"
   },
 
-  "schema:ethdebug/format/pointer/templates": {
-    href: "/spec/pointer/templates"
-  },
-
-  "schema:ethdebug/format/pointer/templates#/$defs/Template": {
-    title: "Pointer template schema",
-    href: "/spec/pointer/templates#template-schema"
+  "schema:ethdebug/format/pointer/template": {
+    href: "/spec/pointer/template"
   },
 
   ...Object.entries({

schemas/pointer.schema.yaml

@@ -153,6 +153,94 @@ examples:
 
   - # example template reference
     define:
-      "contract-variable-slot": 0
+      "string-storage-contract-variable-slot": 0
     in:
-      template: "solidity-string-storage"
+      group:
+        # for short strings, the length is stored as 2n in the last byte of slot
+        - name: "length-flag"
+          location: storage
+          slot: "string-storage-contract-variable-slot"
+          offset:
+            $difference: [$wordsize, 1]
+          length: 1
+
+        # define the region representing the string data itself conditionally
+        # based on odd or even length data
+        - if:
+            $remainder:
+              - $sum:
+                  - $read: "length-flag"
+                  - 1
+              - 2
+
+          # short string case (flag is even)
+          then:
+            define:
+              "string-length":
+                $quotient: [{ $read: "length-flag" }, 2]
+            in:
+              name: "string"
+              location: storage
+              slot: "string-storage-contract-variable-slot"
+              offset: 0
+              length: "string-length"
+
+          # long string case (flag is odd)
+          else:
+            group:
+              # long strings may use full word to describe length as 2n+1
+              - name: "long-string-length-data"
+                location: storage
+                slot: "string-storage-contract-variable-slot"
+                offset: 0
+                length: $wordsize
+
+              - define:
+                  "string-length":
+                    $quotient:
+                      - $difference:
+                        - $read: "long-string-length-data"
+                        - 1
+                      - 2
+
+                  "start-slot":
+                    $keccak256:
+                      - $wordsized: "string-storage-contract-variable-slot"
+
+                  "total-slots":
+                    # account for both zero and nonzero slot remainders by adding
+                    # $wordsize-1 to the length before dividing
+                    $quotient:
+                      - $sum: ["string-length", { $difference: [$wordsize, 1] }]
+                      - $wordsize
+                in:
+                  list:
+                    count: "total-slots"
+                    each: "i"
+                    is:
+                      define:
+                        "current-slot":
+                          $sum: ["start-slot", "i"]
+                        "previous-length":
+                          $product: ["i", $wordsize]
+                      in:
+                        # conditional based on whether this is the last slot:
+                        # is the string length longer than the previous length
+                        # plus this whole slot?
+                        if:
+                          $difference:
+                            - "string-length"
+                            - $sum: ["previous-length", "$wordsize"]
+                        then:
+                          # include the whole slot
+                          name: "string"
+                          location: storage
+                          slot: "current-slot"
+                        else:
+                          # include only what's left in the string
+                          name: "string"
+                          location: storage
+                          slot: "current-slot"
+                          offset: 0
+                          length:
+                            $difference: ["string-length", "previous-length"]

schemas/pointer/template.schema.yaml

@@ -0,0 +1,34 @@
+$schema: "https://json-schema.org/draft/2020-12/schema"
+$id: "schema:ethdebug/format/pointer/template"
+
+title: ethdebug/format/pointer/template
+description: |
+  A schema for representing a pointer defined in terms of some variables whose
+  values are to be provided when invoking the template.
+
+type: object
+properties:
+  expect:
+    title: Template variables
+    description: |
+      An array of variable identifiers used in the definition of the
+      pointer template.
+    type: array
+    items:
+      $ref: "schema:ethdebug/format/pointer/identifier"
+    additionalItems: false
+
+  for:
+    $ref: "schema:ethdebug/format/pointer"
+
+required:
+  - expect
+  - for
+
+additionalProperties: false
+
+examples:
+  - expect: ["slot"]
+    for:
+      location: storage
+      slot: "slot"