Add tokenquote interface

README.md

@@ -638,7 +638,7 @@ Define limits of value amounts of tokens that individual addresses can
 hold.
 
 Limits are inclusive; a limit for 42 means transfer resulting in a token
-balance \_higher\_ than 42 should be rejected.
+balance *higher* than 42 should be rejected.
 
 A return value of 0 indicates that the token is categorically not
 accepted by the holder.
@@ -650,6 +650,9 @@ accepted by the holder.
 #### Solidity interface definition
 
     interface ITokenLimit {
+        // Returns limit of total value a holder will accept of a specific token.
+        // The value limit returned is inclusive; A limit of 42 means any operation resulting in a balance OVER 42 should be rejected.
+        // A value of 0 means that no value of the token is accepted.
         function limitOf(address _token, address _holder) external view returns(uint256);
     }
 
@@ -657,6 +660,29 @@ accepted by the holder.
 
 - <git://holbrook.no/erc20-limiter.git>
 
+### TokenQuote
+
+Quote an output token value for a given value of input tokens.
+
+Both input and output value is denominated in the smallest available
+unit of respective tokens.
+
+#### ERC165 Interface identifier
+
+dbb21d40
+
+#### Solidity interface definition
+
+    interface ITokenQuote {
+        // Returns, within a current context, what value of outTokens the given value of inTokens translates to.
+        // The values are given in smallest unit of each respective token.
+        function valueFor(address _outToken, address _inToken, uint256 value) external view returns (uint256);
+    }
+
+#### Example implementation
+
+- <git://holbrook.no/erc20-limiter.git>
+
 ### TokenRateChange
 
 Enables detection of properties for CIC tokens that change value over

doc/texinfo/overview.texi

@@ -76,6 +76,8 @@ The following well-known solidity interfaces are partially implemented in CIC na
 
 @include tokenlimit.sol.texi
 
+@include tokenquote.sol.texi
+
 @include tokenratechange.sol.texi
 
 @include tokenswap.sol.texi

doc/texinfo/tokenlimit.sol.texi

@@ -2,7 +2,7 @@
 
 Define limits of value amounts of tokens that individual addresses can hold.
 
-Limits are inclusive; a limit for 42 means transfer resulting in a token balance _higher_ than 42 should be rejected.
+Limits are inclusive; a limit for 42 means transfer resulting in a token balance @emph{higher} than 42 should be rejected.
 
 A return value of 0 indicates that the token is categorically not accepted by the holder.
 

doc/texinfo/tokenquote.sol.texi

@@ -0,0 +1,20 @@
+@subsection TokenQuote
+
+Quote an output token value for a given value of input tokens.
+
+Both input and output value is denominated in the smallest available unit of respective tokens.
+
+@subsubsection ERC165 Interface identifier
+
+@include ../../build/TokenQuote.interface
+
+@subsubsection Solidity interface definition
+
+@include ../../build/contract_TokenQuote.texi
+
+@subsubsection Example implementation
+
+@itemize
+@item
+@uref{git://holbrook.no/erc20-limiter.git,}
+@end itemize

python/README.md

@@ -638,7 +638,7 @@ Define limits of value amounts of tokens that individual addresses can
 hold.
 
 Limits are inclusive; a limit for 42 means transfer resulting in a token
-balance \_higher\_ than 42 should be rejected.
+balance *higher* than 42 should be rejected.
 
 A return value of 0 indicates that the token is categorically not
 accepted by the holder.
@@ -650,6 +650,9 @@ accepted by the holder.
 #### Solidity interface definition
 
     interface ITokenLimit {
+        // Returns limit of total value a holder will accept of a specific token.
+        // The value limit returned is inclusive; A limit of 42 means any operation resulting in a balance OVER 42 should be rejected.
+        // A value of 0 means that no value of the token is accepted.
         function limitOf(address _token, address _holder) external view returns(uint256);
     }
 
@@ -657,6 +660,29 @@ accepted by the holder.
 
 - <git://holbrook.no/erc20-limiter.git>
 
+### TokenQuote
+
+Quote an output token value for a given value of input tokens.
+
+Both input and output value is denominated in the smallest available
+unit of respective tokens.
+
+#### ERC165 Interface identifier
+
+dbb21d40
+
+#### Solidity interface definition
+
+    interface ITokenQuote {
+        // Returns, within a current context, what value of outTokens the given value of inTokens translates to.
+        // The values are given in smallest unit of each respective token.
+        function valueFor(address _outToken, address _inToken, uint256 value) external view returns (uint256);
+    }
+
+#### Example implementation
+
+- <git://holbrook.no/erc20-limiter.git>
+
 ### TokenRateChange
 
 Enables detection of properties for CIC tokens that change value over

solidity/TokenLimit.sol

@@ -5,5 +5,8 @@ pragma solidity >=0.6.12;
 // File-version: 1
 
 interface ITokenLimit {
+	// Returns limit of total value a holder will accept of a specific token.
+	// The value limit returned is inclusive; A limit of 42 means any operation resulting in a balance OVER 42 should be rejected.
+	// A value of 0 means that no value of the token is accepted.
 	function limitOf(address _token, address _holder) external view returns(uint256);
 }

solidity/TokenQuote.sol

@@ -0,0 +1,13 @@
+pragma solidity >=0.6.12;
+
+// Author:	Louis Holbrook <dev@holbrook.no> 0826EDA1702D1E87C6E2875121D2E7BB88C2A746
+// SPDX-License-Identifier:	AGPL-3.0-or-later
+// File-version: 1
+
+// Value translator between tokens
+
+interface ITokenQuote {
+	// Returns, within a current context, what value of outTokens the given value of inTokens translates to.
+	// The values are given in smallest unit of each respective token.
+	function valueFor(address _outToken, address _inToken, uint256 value) external view returns (uint256);
+}