Grammar improvements

nois-lang · Jun 4, 2023 · bd964ba · bd964ba
1 parent 6cb4a57
commit bd964ba
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Showing 4 changed files with 88 additions and 59 deletions.
diff --git a/src/grammar.bnf b/src/grammar.bnf
@@ -22,29 +22,23 @@ block           ::= OPEN-BRACE statements CLOSE-BRACE
                 | OPEN-BRACE CLOSE-BRACE
                 ;
 
-expr            ::= sub-expr expr_
+expr            ::= sub-expr infix-operator sub-expr
                 | sub-expr
                 ;
 
-expr_           ::= infix-operator sub-expr
-                ;
-
 sub-expr        ::= unary-expr
                 | operand
-//                | paren-expr
-                ;
-
-unary-expr      ::= prefix-op paren-expr
-                | paren-expr postfix-op
                 ;
 
-paren-expr      ::= OPEN-PAREN expr CLOSE-PAREN
+unary-expr      ::= prefix-op operand
+                | operand postfix-op
                 ;
 
 operand         ::= STRING
                 | CHAR
                 | NUMBER
                 | IDENTIFIER
+                | OPEN-PAREN expr CLOSE-PAREN
                 | type
                 | function-expr
                 | if-expr

diff --git a/src/grammar.json b/src/grammar.json
@@ -88,18 +88,10 @@
       "branches": [
         [
           "sub-expr",
-          "expr_"
-        ],
-        [
+          "infix-operator",
           "sub-expr"
-        ]
-      ]
-    },
-    {
-      "name": "expr_",
-      "branches": [
+        ],
         [
-          "infix-operator",
           "sub-expr"
         ]
       ]
@@ -120,24 +112,14 @@
       "branches": [
         [
           "prefix-op",
-          "paren-expr"
+          "operand"
         ],
         [
-          "paren-expr",
+          "operand",
           "postfix-op"
         ]
       ]
     },
-    {
-      "name": "paren-expr",
-      "branches": [
-        [
-          "open-paren",
-          "expr",
-          "close-paren"
-        ]
-      ]
-    },
     {
       "name": "operand",
       "branches": [
@@ -153,6 +135,11 @@
         [
           "identifier"
         ],
+        [
+          "open-paren",
+          "expr",
+          "close-paren"
+        ],
         [
           "type"
         ],

diff --git a/src/parser/parser.spec.ts b/src/parser/parser.spec.ts
@@ -62,28 +62,57 @@ describe('parser', () => {
         })
     })
 
-    it('parse function-expr', () => {
-        const code = `(): Unit {}`
-        const rule = parse(code, 'function-expr')
+    it('parse unary-expr', () => {
+        const rule = parse('-3', 'unary-expr')
         expect(compactToken(rule!)).toEqual({
-            'name': 'function-expr',
+            'name': 'unary-expr',
             'nodes': [
-                { 'name': 'open-paren', 'value': '(' },
-                { 'name': 'close-paren', 'value': ')' },
-                { 'name': 'colon', 'value': ':' },
                 {
-                    'name': 'type',
-                    'nodes': [
-                        { 'name': 'identifier', 'value': 'Unit' }
-                    ]
-                }, {
-                    'name': 'block',
-                    'nodes': [
-                        { 'name': 'open-brace', 'value': '{' },
-                        { 'name': 'close-brace', 'value': '}' }
-                    ]
+                    'name': 'prefix-op',
+                    'nodes': [{
+                        'name': 'minus', 'value': '-'
+                    }]
+                },
+                {
+                    'name': 'operand',
+                    'nodes': [{
+                        'name': 'number', 'value': '3'
+                    }]
                 }]
         })
     })
 
+    it('parse function-expr', () => {
+        const code = `(): Unit {}`
+        const rule = parse(code, 'expr')
+        expect(compactToken(rule!)).toEqual({
+            'name': 'expr', 'nodes': [{
+                'name': 'sub-expr', 'nodes': [{
+                    'name': 'operand', 'nodes': [{
+                        'name': 'function-expr',
+                        'nodes': [
+                            { 'name': 'open-paren', 'value': '(' },
+                            { 'name': 'close-paren', 'value': ')' },
+                            { 'name': 'colon', 'value': ':' },
+                            {
+                                'name': 'type',
+                                'nodes': [
+                                    { 'name': 'identifier', 'value': 'Unit' }
+                                ]
+                            },
+                            {
+                                'name': 'block',
+                                'nodes': [
+                                    { 'name': 'open-brace', 'value': '{' },
+                                    { 'name': 'close-brace', 'value': '}' }
+                                ]
+                            }
+                        ],
+                    }]
+                }]
+            }]
+
+        })
+    })
+
 })
diff --git a/src/parser/parser.ts b/src/parser/parser.ts
@@ -2,17 +2,35 @@ import { LexerToken, LexerTokenName, TokenLocation } from '../lexer/lexer'
 import { generateParsingTable } from './table'
 import { readFileSync } from 'fs'
 import { join } from 'path'
+import { inspect } from 'util'
 
-export type ParserTokenName
-    = 'program'
-    | 'statement'
-    | 'function-expr'
-    | 'params'
-    | 'params_'
-    | 'param'
-    | 'trailing-comma'
-    | 'block'
-    | 'block_'
+export const parserTokenNames = <const>[
+    'program',
+    'statements',
+    'statement',
+    'variable-def',
+    'type-def',
+    'return-stmt',
+    'block',
+    'expr',
+    'expr_',
+    'sub-expr',
+    'unary-expr',
+    'paren-expr',
+    'operand',
+    'infix-operator',
+    'prefix-op',
+    'postfix-op',
+    'args',
+    'function-expr',
+    'params',
+    'param',
+    'trailing-comma',
+    'type',
+    'type-params',
+    'if-expr',
+]
+export type ParserTokenName = typeof parserTokenNames[number]
 
 export interface ParserToken {
     name: ParserTokenName,
@@ -58,6 +76,7 @@ export const generateTransforms = (tokens: LexerToken[], root: ParserTokenName =
         } else {
             const transform = table.get(<ParserTokenName>stack.at(-1)!)?.get(buffer[0].name)
             if (!transform) {
+                console.debug(inspect({ chain }, { depth: null, colors: true }))
                 throw Error(`syntax error, expected ${stack.at(-1)}, got ${buffer[0].name}, at ${buffer[0].location.start}`)
             }
             chain.push(transform)