caseInsensitive error: expected a Terminal (e.g. "abc")

ohm-js version: 0.14.0

i got an error after moving my working grammar from the online ohm-editor to my node program. when running the following in node:

// test.js
const ohm = require('ohm-js')

ohm.grammar(`
Test {
  Match = i<"foo">
  i<x> = caseInsensitive<x>
}
`)

it fails with the error, complaining about the rule i<x>, apparently:

~/Programming/sceditor $ node test.js
/Users/n642275/Programming/sceditor/node_modules/ohm-js/src/errors.js:233
      throw errors[0];
      ^

Error: Incorrect argument type: expected a Terminal (e.g. "abc")
    at createError (/Users/n642275/Programming/sceditor/node_modules/ohm-js/src/errors.js:20:9)
    at Object.incorrectArgumentType (/Users/n642275/Programming/sceditor/node_modules/ohm-js/src/errors.js:143:10)
    at Apply.pexprs.Apply._assertAllApplicationsAreValid (/Users/n642275/Programming/sceditor/node_modules/ohm-js/src/pexprs-assertAllApplicationsAreValid.js:98:20)
    at Apply.pexprs.PExpr.assertAllApplicationsAreValid (/Users/n642275/Programming/sceditor/node_modules/ohm-js/src/pexprs-assertAllApplicationsAreValid.js:24:8)
    at /Users/n642275/Programming/sceditor/node_modules/ohm-js/src/GrammarDecl.js:115:12
    at Array.forEach (<anonymous>)
    at GrammarDecl.build (/Users/n642275/Programming/sceditor/node_modules/ohm-js/src/GrammarDecl.js:107:30)
    at Semantics.Wrapper.Grammar (/Users/n642275/Programming/sceditor/node_modules/ohm-js/src/main.js:85:20)
    at Operation.doAction (/Users/n642275/Programming/sceditor/node_modules/ohm-js/src/Semantics.js:659:16)
    at Operation.execute (/Users/n642275/Programming/sceditor/node_modules/ohm-js/src/Semantics.js:627:18)

replacing the application of i<"foo"> with righthand caseInsensitive<"foo"> is a workaround the issue.

it works in the online editor, which doesn’t complain about this. might be that the hosted ohm-js script version is newer/older than the npm package?

[alexwarth]

Hi htor,

The issue is that the caseInsensitive rule is not actually a rule. In fact, if you look at the code you’ll see that we called it “case insensitive terminal”. It exists to give the author of a grammar a way to express that a terminal is not case sensitive (which is what you get by default in Ohm). At the time, @pdubroy and I considered just adding a different syntax for case-insensitive terminals, but in the end we decided on this pseudo-rule because it is more explicit. The down side is that the fact that it’s not a full-fledged rule is also confusing, as you’ve discovered. Sorry about that!

And to address ashnur’s comment: yes, it’s been some time since we last made any changes to the code, or published a new version of the npm. But this project is certainly not dead! I for one am still using Ohm in a bunch of different projects.

Best, Alex

[ashnur]

OTOH. you can install the github version from npm with just npm i harc/ohm I think.