Merge pull request #65 from mkantor/boolean-operations

Add `boolean.and` & `boolean.or` to prelude

Author: mkantor

src/language/semantics/prelude.ts

@@ -22,4 +22,6 @@ export const prelude = makeObjectNode({
   '<': integer.less_than,
   '>': integer.greater_than,
   '%': natural_number.modulo,
+  '&&': boolean.and,
+  '||': boolean.or,
 })

src/language/semantics/stdlib/boolean.ts

@@ -1,7 +1,12 @@
 import either from '@matt.kantor/either'
+import option from '@matt.kantor/option'
+import { makeFunctionNode } from '../function-node.js'
 import { type SemanticGraph } from '../semantic-graph.js'
 import { types } from '../type-system.js'
-import { preludeFunction } from './stdlib-utilities.js'
+import {
+  preludeFunction,
+  serializeOnceAppliedFunction,
+} from './stdlib-utilities.js'
 
 type BooleanNode = 'true' | 'false'
 const nodeIsBoolean = (node: SemanticGraph): node is BooleanNode =>
@@ -33,4 +38,76 @@ export const boolean = {
       }
     },
   ),
+  and: preludeFunction(
+    ['boolean', 'and'],
+    {
+      parameter: types.boolean,
+      return: types.boolean,
+    },
+    argument2 => {
+      if (!nodeIsBoolean(argument2)) {
+        return either.makeLeft({
+          kind: 'panic',
+          message: 'argument was not a boolean',
+        })
+      } else {
+        return either.makeRight(
+          makeFunctionNode(
+            {
+              parameter: types.boolean,
+              return: types.integer,
+            },
+            serializeOnceAppliedFunction(['boolean', 'and'], argument2),
+            option.none,
+            argument1 => {
+              if (!nodeIsBoolean(argument1)) {
+                return either.makeLeft({
+                  kind: 'panic',
+                  message: 'argument was not a boolean',
+                })
+              } else {
+                return either.makeRight(String(argument1 && argument2))
+              }
+            },
+          ),
+        )
+      }
+    },
+  ),
+  or: preludeFunction(
+    ['boolean', 'or'],
+    {
+      parameter: types.boolean,
+      return: types.boolean,
+    },
+    argument2 => {
+      if (!nodeIsBoolean(argument2)) {
+        return either.makeLeft({
+          kind: 'panic',
+          message: 'argument was not a boolean',
+        })
+      } else {
+        return either.makeRight(
+          makeFunctionNode(
+            {
+              parameter: types.boolean,
+              return: types.integer,
+            },
+            serializeOnceAppliedFunction(['boolean', 'or'], argument2),
+            option.none,
+            argument1 => {
+              if (!nodeIsBoolean(argument1)) {
+                return either.makeLeft({
+                  kind: 'panic',
+                  message: 'argument was not a boolean',
+                })
+              } else {
+                return either.makeRight(String(argument1 || argument2))
+              }
+            },
+          ),
+        )
+      }
+    },
+  ),
 }