Create a lexer.

2018-07-22 17:37:08 -07:00 · 2018-07-22 17:37:08 -07:00 · 380b12d02c
parent 3ea84f414a
commit 380b12d02c
1 changed files with 74 additions and 0 deletions
--- a/src/chalk/lexer.cr
+++ b/src/chalk/lexer.cr
@ -0,0 +1,74 @@
+require "lex"
+
+module Chalk
+    enum TokenType
+        Any,
+        Str,
+        Id,
+        LitDec,
+        LitBin,
+        LitHex,
+        OpAdd
+        OpSub
+        OpMul
+        OpDiv
+        OpOr
+        OpAnd
+        OpXor
+        KwSprite
+        KwInline
+        KwFun
+        KwU0
+        KwU8
+        KwU12
+        KwVar
+        KwIf
+        KwElse
+        KwWhile
+        KwReturn
+    end
+
+    class Lexer
+        def initialize
+            @lexer = Lex::Lexer.new
+            @lexer.add_pattern(".", TokenType::Any.value)
+            @lexer.add_pattern("\"(\\\\\"|[^\"])*\"",
+                               TokenType::Str.value)
+            @lexer.add_pattern("[a-zA-Z_][a-zA-Z_0-9]*",
+                               TokenType::Id.value)
+            @lexer.add_pattern("[0-9]+",
+                               TokenType::LitDec.value)
+            @lexer.add_pattern("0b[0-1]+",
+                               TokenType::LitBin.value)
+            @lexer.add_pattern("0x[0-9a-fA-F]+",
+                               TokenType::LitHex.value)
+            @lexer.add_pattern("\\+", TokenType::OpAdd.value)
+            @lexer.add_pattern("-", TokenType::OpSub.value)
+            @lexer.add_pattern("\\*", TokenType::OpMul.value)
+            @lexer.add_pattern("/", TokenType::OpDiv.value)
+            @lexer.add_pattern("&", TokenType::OpAdd.value)
+            @lexer.add_pattern("\\|", TokenType::OpOr.value)
+            @lexer.add_pattern("^", TokenType::OpXor.value)
+            @lexer.add_pattern("sprite", TokenType::KwSprite.value)
+            @lexer.add_pattern("inline", TokenType::KwInline.value)
+            @lexer.add_pattern("fun", TokenType::KwFun.value)
+            @lexer.add_pattern("u0", TokenType::KwU0.value)
+            @lexer.add_pattern("u8", TokenType::KwU8.value)
+            @lexer.add_pattern("u12", TokenType::KwU12.value)
+            @lexer.add_pattern("var", TokenType::KwVar.value)
+            @lexer.add_pattern("if", TokenType::KwIf.value)
+            @lexer.add_pattern("else", TokenType::KwElse.value)
+            @lexer.add_pattern("while", TokenType::KwWhile.value)
+            @lexer.add_pattern("return", TokenType::KwReturn.value)
+        end
+
+        def lex(string)
+            return @lexer.lex(string)
+                .select { |t| t[0] != " " }
+                .map do |tuple|
+                    string, id = tuple
+                    { string, TokenType.new(id) }
+                end
+        end
+    end
+end