Skip to content

perf: Replace if-else chain with switch-based token dispatch #103

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
bartveneman merged 1 commit into from
Jan 3, 2026
Merged

perf: Replace if-else chain with switch-based token dispatch #103

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
63 changes: 28 additions & 35 deletions src/tokenize.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -116,41 +116,34 @@ export class Lexer {
let start_column = this.column

// Fast path for single-character tokens
if (ch === CHAR_LEFT_BRACE) {
this.advance()
return this.make_token(TOKEN_LEFT_BRACE, start, this.pos, start_line, start_column)
}
if (ch === CHAR_RIGHT_BRACE) {
this.advance()
return this.make_token(TOKEN_RIGHT_BRACE, start, this.pos, start_line, start_column)
}
if (ch === CHAR_COLON) {
this.advance()
return this.make_token(TOKEN_COLON, start, this.pos, start_line, start_column)
}
if (ch === CHAR_SEMICOLON) {
this.advance()
return this.make_token(TOKEN_SEMICOLON, start, this.pos, start_line, start_column)
}
if (ch === CHAR_COMMA) {
this.advance()
return this.make_token(TOKEN_COMMA, start, this.pos, start_line, start_column)
}
if (ch === CHAR_LEFT_BRACKET) {
this.advance()
return this.make_token(TOKEN_LEFT_BRACKET, start, this.pos, start_line, start_column)
}
if (ch === CHAR_RIGHT_BRACKET) {
this.advance()
return this.make_token(TOKEN_RIGHT_BRACKET, start, this.pos, start_line, start_column)
}
if (ch === CHAR_LEFT_PAREN) {
this.advance()
return this.make_token(TOKEN_LEFT_PAREN, start, this.pos, start_line, start_column)
}
if (ch === CHAR_RIGHT_PAREN) {
this.advance()
return this.make_token(TOKEN_RIGHT_PAREN, start, this.pos, start_line, start_column)
switch (ch) {
case CHAR_LEFT_BRACE:
this.advance()
return this.make_token(TOKEN_LEFT_BRACE, start, this.pos, start_line, start_column)
case CHAR_RIGHT_BRACE:
this.advance()
return this.make_token(TOKEN_RIGHT_BRACE, start, this.pos, start_line, start_column)
case CHAR_COLON:
this.advance()
return this.make_token(TOKEN_COLON, start, this.pos, start_line, start_column)
case CHAR_SEMICOLON:
this.advance()
return this.make_token(TOKEN_SEMICOLON, start, this.pos, start_line, start_column)
case CHAR_COMMA:
this.advance()
return this.make_token(TOKEN_COMMA, start, this.pos, start_line, start_column)
case CHAR_LEFT_BRACKET:
this.advance()
return this.make_token(TOKEN_LEFT_BRACKET, start, this.pos, start_line, start_column)
case CHAR_RIGHT_BRACKET:
this.advance()
return this.make_token(TOKEN_RIGHT_BRACKET, start, this.pos, start_line, start_column)
case CHAR_LEFT_PAREN:
this.advance()
return this.make_token(TOKEN_LEFT_PAREN, start, this.pos, start_line, start_column)
case CHAR_RIGHT_PAREN:
this.advance()
return this.make_token(TOKEN_RIGHT_PAREN, start, this.pos, start_line, start_column)
}

// Whitespace
Expand Down