[BUG] Update grammar.ebnf amber-lang#608 (amber-lang#609)

grammar.ebnf

@@ -6,45 +6,107 @@
 root = { statement_global } ;
 
 (* Statement *)
-statement_local = expression | variable_init | variable_set
-    | loop | loop_array | if_statement | if_chain ;
-statement_global = statement_local | function_def | main
-    | import_all | import_ids;
+statement_local =
+    builtins_statement |
+    expression |
+    if_chain |
+    if_statement |
+    loop |
+    loop_array |
+    variable_init_const |
+    variable_init_mut |
+    variable_set ;
+statement_global =
+    function_def |
+    import_all |
+    import_ids |
+    main |
+    statement_local ;
 
 (* Block *)
 singleline_block = ':', statement_local ;
 multiline_block = '{', { statement_local }, '}' ;
 block = singleline_block | multiline_block ;
 
 (* Expression *)
-expression = number | text | boolean | null | list | command
-    | binary_operation | unary_operation | parentheses | ternary
-    | range | range_inclusive | identifier | function_call ;
+expression =
+    binary_operation |
+    boolean |
+    builtins_expression |
+    command |
+    function_call |
+    identifier |
+    list |
+    null |
+    number |
+    parentheses |
+    range |
+    range_inclusive |
+    ternary |
+    text |
+    unary_operation ;
+
+(* Keywords *)
+KEYWORD_AND = 'and' ;
+KEYWORD_AS = 'as' ;
+KEYWORD_BREAK = 'break' ;
+KEYWORD_CD = 'cd' ;
+KEYWORD_CONST = 'const' ;
+KEYWORD_CONTINUE = 'continue' ;
+KEYWORD_ECHO = 'echo' ;
+KEYWORD_ELSE = 'else' ;
+KEYWORD_EXIT = 'exit' ;
+KEYWORD_FAIL = 'fail' ;
+KEYWORD_FAILED = 'failed' ;
+KEYWORD_FOR = 'for' ;
+KEYWORD_FROM = 'from' ;
+KEYWORD_FUN = 'fun' ;
+KEYWORD_IF = 'if' ;
+KEYWORD_IMPORT = 'import' ;
+KEYWORD_IN = 'in' ;
+KEYWORD_IS = 'is' ;
+KEYWORD_LEN = 'len' ;
+KEYWORD_LET = 'let' ;
+KEYWORD_LINES = 'lines' ;
+KEYWORD_LOOP = 'loop' ;
+KEYWORD_MAIN = 'main' ;
+KEYWORD_MV = 'mv' ;
+KEYWORD_NAMEOF = 'nameof' ;
+KEYWORD_NOT = 'not' ;
+KEYWORD_OR = 'or' ;
+KEYWORD_PUB = 'pub' ;
+KEYWORD_REF = 'ref' ;
+KEYWORD_RETURN = 'return' ;
+KEYWORD_SILENT = 'silent' ;
+KEYWORD_STATUS = 'status' ;
+KEYWORD_THEN = 'then' ;
+KEYWORD_TRUST = 'trust' ;
+KEYWORD_UNSAFE = 'unsafe' ;
 
 (* Terminals *)
 ANY_CHAR = ? any character ? ;
 LETTER = 'A'..'Z' | 'a'..'z' ;
 DIGIT = '0'..'9' ;
 TYPE = 'Text' | 'Num' | 'Bool' | 'Null';
-UNARY_OP = '-' | 'not' ;
-BINARY_OP = '+' | '-' | '*' | '/' | '%' | 'and' | 'or' | '==' | '!=' | '<' | '<=' | '>' | '>=' ;
-SILENT_MOD = 'silent' ;
-TRUST_MOD = 'trust' ;
-VISIBILITY = 'pub' ;
+UNARY_OP = '-' | KEYWORD_NOT ;
+BINARY_OP = '+' | '-' | '*' | '/' | '%' | KEYWORD_AND | KEYWORD_OR | '==' | '!=' | '<' | '<=' | '>' | '>=' ;
+SILENT_MOD = KEYWORD_SILENT ;
+TRUST_MOD = KEYWORD_TRUST ;
+VISIBILITY = KEYWORD_PUB ;
 
 (* Identifier *)
-any_identifier = (LETTER | '_') , { LETTER | '_' | DIGIT } ;
-internal_identifier = '__' , { LETTER | '_' | DIGIT } ;
+any_identifier = (LETTER | '_'), { LETTER | '_' | DIGIT } ;
+internal_identifier = '__', { LETTER | '_' | DIGIT } ;
 identifier = any_identifier - internal_identifier ;
 
 (* `Num` literal *)
-integer = DIGIT , { DIGIT } ;
-real = integer , '.' , integer ;
+integer = DIGIT, { DIGIT } ;
+real = integer, '.', integer ;
 number = integer | real ;
 
 (* `Text` literal *)
-interpolation = '{' , expression , '}' ;
-text = '"' , { ANY_CHAR | interpolation } , '"' ;
+interpolation = '{', expression, '}' ;
+text = '"', { ANY_CHAR | interpolation }, '"' ;
 
 (* `Bool` literal *)
 boolean = 'true' | 'false' ;
@@ -53,8 +115,8 @@ boolean = 'true' | 'false' ;
 null = 'null' ;
 
 (* `List` literal *)
-empty_list = '[' , TYPE , ']' ;
-full_list = '[' , [ expression , { ',' , expression } ] , ']' ;
+empty_list = '[', TYPE, ']' ;
+full_list = '[', [ expression, { ',', expression } ], ']' ;
 list = empty_list | full_list ;
 
 (* Command expression *)
@@ -66,52 +128,72 @@ command = [ SILENT_MOD ], command_base, [ failure_handler ] ;
 command_trust = [ SILENT_MOD ], TRUST_MOD, command_base ;
 
 (* Operations *)
-binary_operation = expression , BINARY_OP , expression ;
-unary_operation = UNARY_OP , expression ;
+binary_operation = expression, BINARY_OP, expression ;
+unary_operation = UNARY_OP, expression ;
 
 (* Parentheses *)
 parentheses = '(', expression, ')' ;
 
 (* Failure handler *)
 failure_propagation = '?';
-failure_block = 'failed', block ;
+failure_block = KEYWORD_FAILED, block ;
 failure_handler = failure_propagation | failure_block ;
 
 (* Variable *)
 variable_index = '[', expression, ']' ;
-variable_init = 'let', identifier, '=', expression ;
+variable_init_mut = KEYWORD_LET, identifier, '=', expression ;
+variable_init_const = KEYWORD_CONST, identifier, '=', expression ;
 variable_get = identifier, variable_index? ;
 variable_set = identifier, variable_index?, '=', expression ;
 
 (* Function *)
 function_call = identifier, '(', [ expression, { ',', expression } ], ')' ;
 function_call_failed = [ SILENT_MOD ], function_call, failure_handler ;
 function_call_trust = [ SILENT_MOD ], TRUST_MOD, function_call ;
-function_def = [ VISIBILITY ], 'fun', identifier, '(', [ identifier, { ',', identifier } ], ')', block ;
-function_def_typed = [ VISIBILITY ], 'fun', identifier, '(',
+function_def = [ VISIBILITY ], KEYWORD_FUN, identifier, '(', [ identifier, { ',', identifier } ], ')', block ;
+function_def_typed = [ VISIBILITY ], KEYWORD_FUN, identifier, '(',
     [ identifier, ':', TYPE, { ',', identifier, ':', TYPE } ], ')', ':', TYPE, block ;
 
 (* Loop *)
-loop = 'loop', block ;
-loop_array = 'loop', identifier, 'in', expression, block ;
-loop_array_iterator = 'loop', identifier, ',', identifier, 'in', expression, block ;
+loop = KEYWORD_LOOP, block ;
+loop_array = KEYWORD_FOR | KEYWORD_LOOP, identifier, KEYWORD_IN, expression, block ;
+loop_array_iterator = KEYWORD_FOR | KEYWORD_LOOP, identifier, ',', identifier, KEYWORD_IN, expression, block ;
 
 (* Ranges *)
 range = expression, '..', expression ;
 range_inclusive = expression, '..=', expression ;
 
 (* Conditional *)
-if_statement = 'if', expression, block, [ 'else', block ] ;
-if_chain = 'if', '{', { expression, block }, [ 'else', block ],  '}' ;
-ternary = expression, 'then', expression, 'else', expression ;
+if_statement = KEYWORD_IF, expression, block, [ KEYWORD_ELSE, block ] ;
+if_chain = KEYWORD_IF, '{', { expression, block }, [ KEYWORD_ELSE, block ],  '}' ;
+ternary = expression, KEYWORD_THEN, expression, KEYWORD_ELSE, expression ;
 
 (* Main *)
-main = 'main', [ '(', identifier, ')' ], block ;
+main = KEYWORD_MAIN, [ '(', identifier, ')' ], block ;
 
 (* Imports *)
 import_path = '"', { ANY_CHAR }, '"' ;
-import_all = [ VISIBILITY ], 'import', '*', 'from', import_path ;
-import_ids = [ VISIBILITY ], 'import', '{', { identifier, [ 'as', identifier ] }, '}', 'from', import_path ;
+import_all = [ VISIBILITY ], KEYWORD_IMPORT, '*', KEYWORD_FROM, import_path ;
+import_ids = [ VISIBILITY ], KEYWORD_IMPORT, '{', { identifier, [ KEYWORD_AS, identifier ], [ ',' ] }, '}', KEYWORD_FROM, import_path ;
 
 (* Comment *)
-comment = '//', { ANY_CHAR }, '\n'
+comment = '//', { ANY_CHAR }, '\n' ;
+
+(* Built-ins *)
+builtins_statement =
+    builtin_cd |
+    builtin_echo |
+    builtin_exit |
+    builtin_mv ;
+builtin_cd = KEYWORD_CD, expression ;
+builtin_echo = KEYWORD_ECHO, expression ;
+builtin_exit = KEYWORD_EXIT, expression ;
+builtin_mv = KEYWORD_MV, expression ;
+
+builtins_expression =
+    builtin_len |
+    builtin_lines |
+    builtin_nameof ;
+builtin_len = KEYWORD_LEN, expression ;
+builtin_lines = KEYWORD_LINES, expression ;
+builtin_nameof = KEYWORD_NAMEOF, expression ;

keywords.ab

@@ -0,0 +1,28 @@
+#! /usr/bin/env amber
+
+import {
+    replace,
+    starts_with,
+    words,
+} from "std/text"
+
+main (args) {
+    let keywords = [Text]
+    let should_append = false
+    for line in lines("grammar.ebnf") {
+        if not should_append and not starts_with(line, "KEYWORD"): continue
+        should_append = true
+        for token in words(line) {
+            if {
+                starts_with(token, "'"): keywords += [replace(token, "'", "")]
+                token == ";": should_append = false
+            }
+        }
+    }
+    let result = $ echo "\$\{{nameof keywords}[@]}" | sort $ failed {
+        echo "Something went wrong while sorting the keywords"
+    }
+    for item in words(result) {
+        echo item
+    }
+}