Smalltalk-style syntax
From Erights
Revision as of 05:12, 19 February 2008 by Kevin Reid (Talk)
User:Kevin Reid's idle speculation on an alternate surface syntax for E.
Translated mint example:
makeMint does { run: name = the any { [sealer, unsealer] = makeBrandPair run: name. mint does { __printOn: out = the void { out print: `<$name's mint>`. } makePurse: var balance an (int >= 0) = the any { decr does { run: amount an (0..balance) = the void { set balance = balance - amount. } }. purse does { __printOn: out = the void { out print: `<has $balance $name bucks>`. } getBalance = the int { balance } sprout = the any { mint makePurse: 0 } getDecr = the any { sealer seal: decr } deposit: amount an int from: src = the void { (unsealer unseal: src getDecr) run: amount. set balance = balance + amount. } }. ^ purse } }. ^ mint } }
Verb mapping
Syntax | Verb | Arity |
---|---|---|
recip foo | "foo" | 0 |
recip foo: arg | "foo" | 1 |
recip foo: arg bar: arg | "foo:bar" | 2 |
recip foo: arg : arg | "foo" | 2 |
recip foo: arg bar: arg baz: arg | "foo:bar:baz" | 3 |
recip foo: arg bar: arg : arg | "foo:bar" | 3 |
The traditional Smalltalk/ObjC form would include an additional colon at the end of the >0-arg verbs, but this would drop it for compatibility with normal E protocols.
There would also need to be a way to use arbitrary verbs as normal E surface syntax provides (the "verb-string" syntax).