added first draft implementation for slices for ohm grammar, core, analyzer and generator.

Author: MatthewSavitt

src/analyzer.js

@@ -151,6 +151,14 @@ export default function analyze(match) {
       );
     },
 
+    SliceExpr(expr, _backslash, rest) {
+      const expressions = [expr.rep()];
+      if (rest.children.length > 0) {
+        expressions.push(...rest.children.map(child => child.rep()));
+      }
+      return core.sliceExpr(expressions);
+    },
+
     CondExpr_ternary(
       _question,
       condLeft,

src/core.js

@@ -21,6 +21,10 @@ export function expr(condExpr, rest = []) {
   return { type: condExpr.type, kind: "Expr", condExpr, rest };
 }
 
+export function sliceExpr(expressions) {
+  return { type: expressions[0].type, kind: "SliceExpr", expressions };
+}
+
 export function condExpr(leftCond, op, rightCond, thenBranch, elseBranch) {
   return {
     type: thenBranch?.type ?? anyType,

src/funktion.ohm

@@ -1,9 +1,10 @@
 Funktion {
   Program        = (GlobalRange "\n")? "\n"* ListOf<(Statement | FuncDef | ""), ("\n"+ | space+)>
 
-  FuncDef        = id "(" id ")" "=" "\n"? Expr (";" (FuncDef | Expr))*
+  FuncDef        = id "(" id ")" "=" "\n"? SliceExpr (";" (FuncDef | SliceExpr))*
   FuncCall		   = id "(" Expr ")"
   Expr           = CondExpr ("," "\n"? CondExpr)*
+  SliceExpr      = Expr ("\\" Expr)*
   CondExpr       = "?" CondExpr ("==" | "!=" | "<=" | "<" | ">=" | ">") CondExpr "=>" BitwiseExpr ":" "\n"? CondExpr --ternary
                  | BitwiseExpr
   BitwiseExpr    = BitwiseExpr ("&" | "|" | "^") ShiftExpr              --binary

src/generator.js

@@ -70,22 +70,25 @@ export default function generate(program) {
           if (gen.size === 0) {
             gen.size++;
             gen.index++;
-            gen.values.push(f(currentVal));
+            const result = f(currentVal);
+            gen.values.push(Array.isArray(result) ? result.join(' ') : result);
             currentVal += gen.timestepRange.step;
           }
           if (gen.timestepRange.step > 0) {
             while (currentVal <= gen.timestepRange.end && iterations > 0) {
               gen.size++;
               gen.index++;
-              gen.values.push(f(currentVal));
+              const result = f(currentVal);
+              gen.values.push(Array.isArray(result) ? result.join(' ') : result);
               currentVal += gen.timestepRange.step;
               iterations--;
             }
           } else {
             while (currentVal >= gen.timestepRange.end && iterations > 0) {
               gen.size++;
               gen.index++;
-              gen.values.push(f(currentVal));
+              const result = f(currentVal);
+              gen.values.push(Array.isArray(result) ? result.join(' ') : result);
               currentVal += gen.timestepRange.step;
               iterations--;
             }
@@ -102,8 +105,21 @@ export default function generate(program) {
       const funcName = targetName(d.name);
       const param = targetName(d.param);
       const body = gen(d.body);
-      const lastStmt = body.pop();
-      output.push(`function ${funcName}(${param}) {\n${body}\nreturn ${lastStmt};\n} `);
+
+      // check for slices in the body of the function
+      if (d.body.kind === "SliceExpr") {
+        const sliceExpressions = d.body.expressions.map(expr => {
+          return `${gen(expr)}`;
+        }).join(", ");
+
+        output.push(`function ${funcName}(${param}) {
+          return [${sliceExpressions}];
+        }`);
+      } else {
+        // handle same as before if not a slice
+        const lastStmt = body.pop();
+        output.push(`function ${funcName}(${param}) {\n${body}\nreturn ${lastStmt};\n} `);
+      }
       if (!instantiatedMutableRanges.has(param)) {
         output.push(`let ${param} = initializeMutableRange();`);
         instantiatedMutableRanges.add(param)
@@ -129,6 +145,13 @@ export default function generate(program) {
       return exprs;
     },
 
+    //anywhere you see SliceExpr in the code, I added it in  ~MS
+    SliceExpr(e) {
+      const slices = e.expressions.map(gen);
+      // join slices with spaces in output
+      return `[${slices.join(', ')}]`;
+    },
+
     CondExpr(e) {
       if (e.thenBranch) {
         const condleft = gen(e.leftCond);