Reserved Keywords vs long Identider (multi-words)

Question

I would like to create a MiniLang with friendly function name
This is my sample script and expected statement

                              // actual                   // expected    
set a = true;                 // 'set a' -> IDs             // 'set' -> Set, 'a' -> IDS    
Set name ('hello');           // 'Set name' -> IDs          // 'Set name' -> IDs    
set b = my friendly variable; // 'set b' -> IDs             // 'set' -> Set, 'b' -> IDS    
set my variable = 10;         // 'set my variable' -> IDs   // 'set' -> Set, 'my variable' -> IDs    
Calculate sum (1, 2, 4);      // 'Calculate sum' -> IDs     // 'Calculate sum' -> IDs

I would like some reserved keywords will be matched before IDs (identifier with multi-words). But ANTLR4 matches IDs only. I try to define keywords before IDs but not effect.

How to define rule for keyword of statement be matched before IDs

Thanks!

This is my grammar

  grammar MiniLang;

  document    
      : (stmt NL*)+ EOF
      ;
  stmt        
      : Set Space+ IDs Space* '=' Space* expr Space* ';'                          # SetStatement
      | IDs Space* '(' Space* (expr (Space*(',' expr))*)? Space* ')' Space* ';'   # FunctionCall
      ;
  expr 
      : atom 
      ;
  atom       
      : IDs 
      | Number
      | String
      ;
  Set         
      : 'set'
      ;
  Space       
      : ' '
      ;
  Number         
      : [0-9]+
      ;
  ID          
      : [a-zA-Z][a-zA-Z0-9]*
      ;
  IDs         
      : ID (Space ID)*
      ;
  String      
      : ['] (~['\r\n\\] | EscapeSequence)* ['] 
      ;
  EscapeSequence    
      : '\\' [']
      ;
  NL          
      : [\r\n]
      ;

Answer 1

The lexer tries to match as much as possible. Therefore you will need to change the IDs rule into a parser rule instead:

ids
 : ID+
 ;

Space
 : [ \t] -> skip
 ;

Or if you're going to keep spaces:

ids
 : ID (Space ID)*
 ;