Wrote the buggy CSS parser

Author: ralt

Block.go

@@ -1,33 +1,157 @@
 package cssminify
 
 import (
+	"bytes"
+	"fmt"
 	"io/ioutil"
+	"strings"
 )
 
 type Block struct {
-	selector string
-	pair     Pair
+	selector []byte
+	pairs    []Pair
 }
 
+// Error constants
+const (
+	NOT_IN_SELECTOR = "Met { while not being in selector"
+	NOT_AFTER_VALUE = "Met } after a non-value"
+	NOT_IN_PROPERTY = "Met : after a non-property"
+	NOT_IN_VALUE    = "Met ; after a non-value"
+)
+
+// Parser constants
+const (
+	STARTING_COMMENT = 0
+	IN_COMMENT       = 1
+	CLOSING_COMMENT  = 2
+	IN_SELECTOR      = 3
+	IN_PROPERTY      = 4
+	IN_VALUE         = 5
+)
+
 func Blocks(file string) []Block {
 	var (
-		block  Block
-		blocks = make([]Block, 0)
+		blocks       []Block
+		letter       byte
+		current      []byte
+		beforeState  byte
+		state        byte
+		currentBlock Block
+		currentPair  Pair
 	)
 
-	content := readFile(file)
+	content := []byte(readFile(file))
+
+	for letter, content = stripLetter(content); letter != 0; letter, content = stripLetter(content) {
+		if state == STARTING_COMMENT && letter != '*' {
+			state = beforeState
+		}
+		if state == CLOSING_COMMENT && letter != '/' {
+			state = beforeState
+		}
+		switch letter {
+		case '/':
+			switch state {
+			case CLOSING_COMMENT:
+				state = beforeState
+
+				// Since we don't keep comments
+				current = []byte{}
+			default:
+				if state != IN_COMMENT {
+					beforeState = state
+					state = STARTING_COMMENT
+					current = append(current, letter)
+				}
+			}
+		case '*':
+			switch state {
+			case STARTING_COMMENT:
+				beforeState = state
+				state = IN_COMMENT
+				current = append(current, letter)
+			case IN_COMMENT:
+				state = CLOSING_COMMENT
+				current = append(current, letter)
+			}
+		case '{':
+			if state != IN_COMMENT {
+				if state == IN_SELECTOR {
+					state = IN_PROPERTY
+					currentBlock.selector = current
+					current = []byte{}
+				} else {
+					panic(NOT_IN_SELECTOR)
+				}
+			}
+		case '}':
+			if state != IN_COMMENT {
+				if state == IN_VALUE && !bytes.Equal(nil, current) {
+					state = IN_PROPERTY
+					currentPair.value = current
+					currentBlock.pairs = append(currentBlock.pairs, currentPair)
+				}
+				if state == IN_PROPERTY && strings.Trim(string(current), " ") != "" {
+					current = []byte{}
+					blocks = append(blocks, currentBlock)
+					currentBlock = Block{}
+					state = IN_SELECTOR
+				} else {
+					panic(NOT_AFTER_VALUE)
+				}
+			}
+		case ':':
+			if state != IN_COMMENT {
+				if state == IN_PROPERTY && !bytes.Equal(nil, current) {
+					state = IN_VALUE
+					currentPair.property = current
+
+					// Cleanup
+					current = []byte{}
+				} else {
+					if state != IN_VALUE && state != IN_SELECTOR {
+						panic(NOT_IN_PROPERTY)
+					}
+				}
+			}
+		case ';':
+			if state != IN_COMMENT {
+				if state == IN_VALUE {
+					state = IN_PROPERTY
+					currentPair.value = current
+					currentBlock.pairs = append(currentBlock.pairs, currentPair)
+
+					// Cleanup
+					currentPair = Pair{}
+					current = []byte{}
+				} else {
+					panic(NOT_IN_VALUE)
+				}
+			}
+		default:
+			if state != IN_COMMENT {
+				if state == 0 {
+					state = IN_SELECTOR
+				}
+				current = append(current, letter)
+			}
+		}
 
-	block = createBlockFromFile(&content)
-	for block.selector != "" {
-		blocks = append(blocks, block)
-		block = createBlockFromFile(&content)
 	}
 
 	return blocks
 }
 
-func createBlockFromFile(content *string) Block {
-	return Block{}
+func stripLetter(content []byte) (byte, []byte) {
+	var letter byte
+	if len(content) != 0 {
+		letter = content[0]
+		content = content[1:]
+	} else {
+		content = []byte{}
+	}
+	return letter, content
 }
 
 func readFile(root string) string {

Pair.go

@@ -1,6 +1,6 @@
 package cssminify
 
 type Pair struct {
-	property string
-	value    string
+	property []byte
+	value    []byte
 }